CA1133049A - Electrochemical cell having mixed soluble depolarizer including halogens and interhalogens - Google Patents
Electrochemical cell having mixed soluble depolarizer including halogens and interhalogensInfo
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- CA1133049A CA1133049A CA347,514A CA347514A CA1133049A CA 1133049 A CA1133049 A CA 1133049A CA 347514 A CA347514 A CA 347514A CA 1133049 A CA1133049 A CA 1133049A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M6/00—Primary cells; Manufacture thereof
- H01M6/14—Cells with non-aqueous electrolyte
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Abstract
ABSTRACT of the Disclosure An electrochemical cell comprising an anode of a metal above hydrogen in the electromotive series and which is electrochemically oxidizable to form metal ions in the cell upon discharge such as alkali metals and alkaline earth metals, a cathode of electronically conductive material such as carbon, and an ionic conductive electrolytic solution operatively associated with the anode and cathode and comprising a halogen and/or interhalogen dissolved in a non-aqueous solvent, the halogen and/or interhalogen serving as a soluble depolarizer and as a cosolvent in the cell.
The non-aqueous solvent can be an organic solvent which is substantially inert to the material of the anode and cathode or the solvent can be an inorganic solvent which serves as both a solvent and as a depolarizer in the cell. A metal salt can be dissolved in the electrolytic solution to enhance the ionic conduction thereof.
The non-aqueous solvent can be an organic solvent which is substantially inert to the material of the anode and cathode or the solvent can be an inorganic solvent which serves as both a solvent and as a depolarizer in the cell. A metal salt can be dissolved in the electrolytic solution to enhance the ionic conduction thereof.
Description
BACKGROUND OF THE IN~ENTION
.
1 This invention relates to the art of electrochemical cells, and more particularly to a new and improved electrochemical cell includinp, an oxidizable active metal anode and a mixed soluble depolarizer including a halogen and/or interhalogen.
In the development of high energy density electro-chemical cells, much recent work has involved the use of highly reactive metals such as lithium for the anode or negative electrode. Work on electrolytes for such cells has included at least three approaches, one of which is to employ a high temperature inorganic molten salt electrolyte. The high temperature of operation required by this approach, however, necessitates heating apparatus and insulation which, in turn, give rise to considerations of weight, complexity and cost.
Also, due to the nature of the materials employed, such as molten lithium, the cells can have a relatively short operating life. Another approach is to employ an organic solvent-based electrolyte or an electrolyte consisting of an inorganic salt in an organic solvent.
Cells developed according to this approach have the advantage of operation at room temperature, although they cannot provide a power density as high as some cells developed according to the first approach. A
third approach is to provide a solid electrolyte in the form of a lithium halide ionic compound which has proved to be highly reliable. There are, however,
.
1 This invention relates to the art of electrochemical cells, and more particularly to a new and improved electrochemical cell includinp, an oxidizable active metal anode and a mixed soluble depolarizer including a halogen and/or interhalogen.
In the development of high energy density electro-chemical cells, much recent work has involved the use of highly reactive metals such as lithium for the anode or negative electrode. Work on electrolytes for such cells has included at least three approaches, one of which is to employ a high temperature inorganic molten salt electrolyte. The high temperature of operation required by this approach, however, necessitates heating apparatus and insulation which, in turn, give rise to considerations of weight, complexity and cost.
Also, due to the nature of the materials employed, such as molten lithium, the cells can have a relatively short operating life. Another approach is to employ an organic solvent-based electrolyte or an electrolyte consisting of an inorganic salt in an organic solvent.
Cells developed according to this approach have the advantage of operation at room temperature, although they cannot provide a power density as high as some cells developed according to the first approach. A
third approach is to provide a solid electrolyte in the form of a lithium halide ionic compound which has proved to be highly reliable. There are, however,
2 .
~33049 1 some applications which call for a battery having a relatively higher current capability.
Summary of the Invention It is, therefore, a primary object of this invention to provide a new and improved electrochemical cell of relatively high energy density having a relatively high current capability.
It is a further object of this invention to provide such an electrochemical cell of high reliability.
It is a further object of this invention to provide such an electrochemical cell having a relatively high open circuit voltage and current capacity.
It is a further object to provide such an electro-chemical cell having an oxidizable active anode material and an electrolyte including a non-aqueous solvent.
The present invention provides an electrochemical cell of high energy density including a halogen and/or interhalogen dissolved in a non-aqueous solvent serving as a soluble depolarizer wherein the halogen and/or interhalogen also serves as a cosolvent in the cell.
The electrochemical cell comprises an anode of a metal above hydrogen in the electromotive series, a cathode of electronically conductive material, and an ionic conductive electrolytic solution operatively associated with the anode and cathode, the electrolytic solution consisting essentially of a first component selected from 11~304~
1 the group consisting of free halogens, interhalogens and mixtures thereof dissolved in a second component in the form of a non-aqueous solvent or a mixture of non-aqueous solvents. The anode can comprise a metal which is electrochemically oxidizable to form metal ions in the cell, for example alkali metals and alkaline earth metals, and the cathode can comprise electronically conductive material such as carbon. The non-aqueous solvent can be an organic solvent which is substantially inert to the material of the anode and cathode, or the solvent can be an inorganic solvent which serves as both a solvent and as a depolarizer in the cell. A
metal salt can be dissolved in the electrolytic solution to enhance the ionic conduction thereof.
The foregoing and additional advantages and characterizing features of the present invention will become clearly apparent upon a reading of the ensuing detailed description.
Brief Description Of The Drawing Figures Fig. 1 is a graph including plots of discharge characteristics for a test cell and a cell according to one embodiment of the present invention;
Fig. 2 is a graph including plots of discharge characteristics for a test cell and a cell according to another embodiment of the present invention;
Fig. 3 is a graph including a plot of the discharge characteristic of a cell according to another embodiment of the present invention;
~330~19 1 Fig. 4 is a graph including plots of discharge characteristics for a test cell and a prototype cell according to an embodiment of the present invention;
Fig. 5 is a graph including plots of discharge characteristics for a prototype cell according to an embodiment of the present invention for various load resistances;
Fig. 6 is a graph including plots of low rate discharge characteristics for a prototype cell according to an embodiment of the present invention for various load resistances;
Fig. 7 is a graph including plots of high temperature discharge characteristics for a prototype cell according to an embodiment of the present invention for various load resistances;
Fig. ~ is a graph including plots of low temperature discharge characteristics for a prototype cell according to an embodiment of the present invention for various load resistances; and Fig. 9 is a graph including a plot of discharge characteristics of a cell according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The electrochemical cell of the present invention com~rises an anode of a metal above hydrogen in the electromotive series and which is electrochemically oxidizable to form metal ions in the cell upon discharge to generate a flow of electrons in an external electrical circuit connected to the cell. Preferred metals are al~ali metals and alkaline earth -..~
11;~3049 1 metals. Exemplary metals are lithium, sodium, magnesium, calcium and strontium and alloys and intermetallic compounds including alkali metals and alkaline earth metals such as Li-Al alloys and intermetallic compounds, Li-B alloys and intermetallic compounds, and Li-Si-E alloys and intermetallic compounds. Other metals can be employed which, like lithium, can function as the anode metal in the cell environment. The form of the anode typically is a thin sheet or foil of the anode metal, and a current collector having an extending tab or lead is affixed to the anode sheet or foil.
The electrochemical cell of the present invention further comprises a cathode of electronically conductive material which serves as the other electrode of the cell. The electro-chemical reaction at the cathode involves conversion of ions which migrate from the anode to the cathode into atomic or molecular forms. In addition to being electronically conductive, the material of the cathode may also be electro-active. Exemplary cathode materials include graphite, and graphite or carbon bonded on metal screens. Examples of cathode materials which are electronically conductive and electro-active include titanium disulfide and lead dioxide.
The form of the cathode typically is a thin layer of carbon pressed, spread or otherwise applied to a metal screen current collector.
The electrochemical cell of the present invention further comprises a non-aqueous, ionic conductive electrolytic solution operativelyassociated with the anode and the cathode. The electrolytic solution serves as a medium for migration of ions 113304~9 1 between the anode and cathode during the cell electrochemical reactions. In accordance with the present invention, the electro-lytic solution comprises a halogen and/or interhalogen dissolved in a non-aqueous solvent, the halogen and/or inter-halogen serving a s a soluble depolarizer in the high energy density cell. The halogen and/or interhalogen also can serve as a cosolvent in the electrochemical cell.
The halogen can be iodine, bromine, chlorine or fluorine.
The interhalogen can be ClF, ClF3, lCl, lC13, lBr, lF3 IF5, BrCl, BrF, BrF3, or BrF5. The non-aqueous solvent may be one of the organic solvents which is substantially inert to the anode and cathode electrode materials such as tetrahydrofuran, propylene carbonate, acetonitrile, dimethyl sulfoxide, dimethyl foramide, dimethyl acetamide and others.
Tne non-aqueous solvent also may be one or a mixture of more than one of the inorganic solvents which can serve as both a solvent and a depolarizer such as thionyl chloride, sulfuryl chloride, selenium oxychloride, chromyl chloride, phosphoryl chloride, phosphorous sulfur trichloride and others. The ionic conduction of the non-aqueous electrolytic solution may be facilitated by dissolving a metal salt in the non-aqueous halogen solvent. Examples of metal salts are lithium halides such as LiCl and LiBr and lithium salts of the LiMxn type such as LiAlC14 Li2A12Cl~0, LiC104, LiAsF6, LiSbF6, LiSbC16 Li2TiC16 Li2SeC16, Li2BloCl Li2B12C112 and others 11;~3~;~4~
1 Thus, the solution of halogen and/or interhalogen, non-a~ueous solvent and ionic salt if employed serves as the depolarizer and electrolyte of the cell.
When the mechanical structure or confi~uration of the cell requires, a separator can be employed to provide physical separation between the anode and the cathode current collector.
The separator is of electrically insulative material to prevent an internal electrical short circuit in the cell between the anode and the cathode current collector. The separator material also must be chemically unreactive with the materials of the anode and cathode current collector and both chemically unreactive with and insoluble in the electrolytic solution.
In addition, the separator material must have a degree of porosity sufficient to allow flow therethrough of the electrolytic solution during the electrochemical reaction of the cell. Illustrative separator materials include non-woven glass, Teflon, glass fiber material ceramics and materials commercially available under the designations Zitex, Celgard and Dexiglas. The form of the separator typically is a sheet which is placed between the anode and cathode of the cell in a manner preventing physical contact between the anode and cathode, and such contact also is prevented when the combination is rolled or otherwise formed into a cylindrical configuration.
The electrochemical cell of the present invention operates in the following manner. When the ionic conductive electrolytic solution becomes operatively 11;~3049 1 associated with the anode and cathocle of the cell, an electrical potential difference is cleveloped between terminals operatively connected to the anode and cathode.
The electrochemical reaction at the anode includes oxidation to form metal ions during discharge of the cell.
The electrochemical reaction at the cathode involves conversion of ions which migrate from the anode to the cathode into atomic or molecular forms. In addition, the halogen and/or interhalogen of the electrolytic solution is believed to undergo a reaction or reactions with the non-aqueous solvent thereof resulting in the formation of a compound or complex which exhibits the observed open cirucit voltage of the cell.
The electrochemical cell according to the present invention is illustrated further by the following examples.
Example I
A test cell was constructed having a lithium anode, a carbon cathode and an electrolyte comprising lithium bromide dissolved in selenium oxychloride. In particular, the anode of the cell was a lithium foil having a width of about 1.~ cm., a length of about 6.6 cm. and a thickness of about 0.056 cm. with a nickel current collector having an extending lead or tab cold welded on the lithium foil.
The cathode was fabricated by providing a thin layer of carbon having a width of about 1.5 cm., a length of about 7.0 cm. and a weight of about 173 milligrams and then by pressing _9_ 1 the carbon layer on a thin expanded metal screen of stain-less steel having an extending lead or tab. A separator in the form of a sheet of Celgrad material also was provided and placed between the anode and cathode layers, whereupon the anode/separator/cathode assembly or combination was rolled or wound into a cylindrical configuration and placed in a glass vial having an outer diameter of about 1.3 cm. with the anode and cathode current collector leads extending out through the open end of the vial. A depolarizer-electrolyte solution was prepared comprising lithium bromidedissolved in selenium oxychloride to provide a O.lM
solution having a total volume of 2.0 ml. The solution was injected into the glass vial, and then the open end of the vial was sealed closed with a Teflon lined stopper in a manner maintaining the spaced anode and cathode leads externally accessible for electrical connection. The test cell had an open circuit voltage of about 3.55 volts and then an initial load voltage of about 3.45 volts when discharged at room temperature under a constant load of 3.3 kilohms. After fourty eight hour discharge period the load voltage was about
~33049 1 some applications which call for a battery having a relatively higher current capability.
Summary of the Invention It is, therefore, a primary object of this invention to provide a new and improved electrochemical cell of relatively high energy density having a relatively high current capability.
It is a further object of this invention to provide such an electrochemical cell of high reliability.
It is a further object of this invention to provide such an electrochemical cell having a relatively high open circuit voltage and current capacity.
It is a further object to provide such an electro-chemical cell having an oxidizable active anode material and an electrolyte including a non-aqueous solvent.
The present invention provides an electrochemical cell of high energy density including a halogen and/or interhalogen dissolved in a non-aqueous solvent serving as a soluble depolarizer wherein the halogen and/or interhalogen also serves as a cosolvent in the cell.
The electrochemical cell comprises an anode of a metal above hydrogen in the electromotive series, a cathode of electronically conductive material, and an ionic conductive electrolytic solution operatively associated with the anode and cathode, the electrolytic solution consisting essentially of a first component selected from 11~304~
1 the group consisting of free halogens, interhalogens and mixtures thereof dissolved in a second component in the form of a non-aqueous solvent or a mixture of non-aqueous solvents. The anode can comprise a metal which is electrochemically oxidizable to form metal ions in the cell, for example alkali metals and alkaline earth metals, and the cathode can comprise electronically conductive material such as carbon. The non-aqueous solvent can be an organic solvent which is substantially inert to the material of the anode and cathode, or the solvent can be an inorganic solvent which serves as both a solvent and as a depolarizer in the cell. A
metal salt can be dissolved in the electrolytic solution to enhance the ionic conduction thereof.
The foregoing and additional advantages and characterizing features of the present invention will become clearly apparent upon a reading of the ensuing detailed description.
Brief Description Of The Drawing Figures Fig. 1 is a graph including plots of discharge characteristics for a test cell and a cell according to one embodiment of the present invention;
Fig. 2 is a graph including plots of discharge characteristics for a test cell and a cell according to another embodiment of the present invention;
Fig. 3 is a graph including a plot of the discharge characteristic of a cell according to another embodiment of the present invention;
~330~19 1 Fig. 4 is a graph including plots of discharge characteristics for a test cell and a prototype cell according to an embodiment of the present invention;
Fig. 5 is a graph including plots of discharge characteristics for a prototype cell according to an embodiment of the present invention for various load resistances;
Fig. 6 is a graph including plots of low rate discharge characteristics for a prototype cell according to an embodiment of the present invention for various load resistances;
Fig. 7 is a graph including plots of high temperature discharge characteristics for a prototype cell according to an embodiment of the present invention for various load resistances;
Fig. ~ is a graph including plots of low temperature discharge characteristics for a prototype cell according to an embodiment of the present invention for various load resistances; and Fig. 9 is a graph including a plot of discharge characteristics of a cell according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The electrochemical cell of the present invention com~rises an anode of a metal above hydrogen in the electromotive series and which is electrochemically oxidizable to form metal ions in the cell upon discharge to generate a flow of electrons in an external electrical circuit connected to the cell. Preferred metals are al~ali metals and alkaline earth -..~
11;~3049 1 metals. Exemplary metals are lithium, sodium, magnesium, calcium and strontium and alloys and intermetallic compounds including alkali metals and alkaline earth metals such as Li-Al alloys and intermetallic compounds, Li-B alloys and intermetallic compounds, and Li-Si-E alloys and intermetallic compounds. Other metals can be employed which, like lithium, can function as the anode metal in the cell environment. The form of the anode typically is a thin sheet or foil of the anode metal, and a current collector having an extending tab or lead is affixed to the anode sheet or foil.
The electrochemical cell of the present invention further comprises a cathode of electronically conductive material which serves as the other electrode of the cell. The electro-chemical reaction at the cathode involves conversion of ions which migrate from the anode to the cathode into atomic or molecular forms. In addition to being electronically conductive, the material of the cathode may also be electro-active. Exemplary cathode materials include graphite, and graphite or carbon bonded on metal screens. Examples of cathode materials which are electronically conductive and electro-active include titanium disulfide and lead dioxide.
The form of the cathode typically is a thin layer of carbon pressed, spread or otherwise applied to a metal screen current collector.
The electrochemical cell of the present invention further comprises a non-aqueous, ionic conductive electrolytic solution operativelyassociated with the anode and the cathode. The electrolytic solution serves as a medium for migration of ions 113304~9 1 between the anode and cathode during the cell electrochemical reactions. In accordance with the present invention, the electro-lytic solution comprises a halogen and/or interhalogen dissolved in a non-aqueous solvent, the halogen and/or inter-halogen serving a s a soluble depolarizer in the high energy density cell. The halogen and/or interhalogen also can serve as a cosolvent in the electrochemical cell.
The halogen can be iodine, bromine, chlorine or fluorine.
The interhalogen can be ClF, ClF3, lCl, lC13, lBr, lF3 IF5, BrCl, BrF, BrF3, or BrF5. The non-aqueous solvent may be one of the organic solvents which is substantially inert to the anode and cathode electrode materials such as tetrahydrofuran, propylene carbonate, acetonitrile, dimethyl sulfoxide, dimethyl foramide, dimethyl acetamide and others.
Tne non-aqueous solvent also may be one or a mixture of more than one of the inorganic solvents which can serve as both a solvent and a depolarizer such as thionyl chloride, sulfuryl chloride, selenium oxychloride, chromyl chloride, phosphoryl chloride, phosphorous sulfur trichloride and others. The ionic conduction of the non-aqueous electrolytic solution may be facilitated by dissolving a metal salt in the non-aqueous halogen solvent. Examples of metal salts are lithium halides such as LiCl and LiBr and lithium salts of the LiMxn type such as LiAlC14 Li2A12Cl~0, LiC104, LiAsF6, LiSbF6, LiSbC16 Li2TiC16 Li2SeC16, Li2BloCl Li2B12C112 and others 11;~3~;~4~
1 Thus, the solution of halogen and/or interhalogen, non-a~ueous solvent and ionic salt if employed serves as the depolarizer and electrolyte of the cell.
When the mechanical structure or confi~uration of the cell requires, a separator can be employed to provide physical separation between the anode and the cathode current collector.
The separator is of electrically insulative material to prevent an internal electrical short circuit in the cell between the anode and the cathode current collector. The separator material also must be chemically unreactive with the materials of the anode and cathode current collector and both chemically unreactive with and insoluble in the electrolytic solution.
In addition, the separator material must have a degree of porosity sufficient to allow flow therethrough of the electrolytic solution during the electrochemical reaction of the cell. Illustrative separator materials include non-woven glass, Teflon, glass fiber material ceramics and materials commercially available under the designations Zitex, Celgard and Dexiglas. The form of the separator typically is a sheet which is placed between the anode and cathode of the cell in a manner preventing physical contact between the anode and cathode, and such contact also is prevented when the combination is rolled or otherwise formed into a cylindrical configuration.
The electrochemical cell of the present invention operates in the following manner. When the ionic conductive electrolytic solution becomes operatively 11;~3049 1 associated with the anode and cathocle of the cell, an electrical potential difference is cleveloped between terminals operatively connected to the anode and cathode.
The electrochemical reaction at the anode includes oxidation to form metal ions during discharge of the cell.
The electrochemical reaction at the cathode involves conversion of ions which migrate from the anode to the cathode into atomic or molecular forms. In addition, the halogen and/or interhalogen of the electrolytic solution is believed to undergo a reaction or reactions with the non-aqueous solvent thereof resulting in the formation of a compound or complex which exhibits the observed open cirucit voltage of the cell.
The electrochemical cell according to the present invention is illustrated further by the following examples.
Example I
A test cell was constructed having a lithium anode, a carbon cathode and an electrolyte comprising lithium bromide dissolved in selenium oxychloride. In particular, the anode of the cell was a lithium foil having a width of about 1.~ cm., a length of about 6.6 cm. and a thickness of about 0.056 cm. with a nickel current collector having an extending lead or tab cold welded on the lithium foil.
The cathode was fabricated by providing a thin layer of carbon having a width of about 1.5 cm., a length of about 7.0 cm. and a weight of about 173 milligrams and then by pressing _9_ 1 the carbon layer on a thin expanded metal screen of stain-less steel having an extending lead or tab. A separator in the form of a sheet of Celgrad material also was provided and placed between the anode and cathode layers, whereupon the anode/separator/cathode assembly or combination was rolled or wound into a cylindrical configuration and placed in a glass vial having an outer diameter of about 1.3 cm. with the anode and cathode current collector leads extending out through the open end of the vial. A depolarizer-electrolyte solution was prepared comprising lithium bromidedissolved in selenium oxychloride to provide a O.lM
solution having a total volume of 2.0 ml. The solution was injected into the glass vial, and then the open end of the vial was sealed closed with a Teflon lined stopper in a manner maintaining the spaced anode and cathode leads externally accessible for electrical connection. The test cell had an open circuit voltage of about 3.55 volts and then an initial load voltage of about 3.45 volts when discharged at room temperature under a constant load of 3.3 kilohms. After fourty eight hour discharge period the load voltage was about
3.4 volts. The cell realized a total discharge capacity of approximately 73 milliampere hours to a 3.0 volt cutoff.
Example II
A laboratory cell according to the present invention was constructed including a lithium anode, a carbon cathode and an ionic conductive electrolytic solution comprising ~, 113304'9 1 a halogen dissolved in a non-aqueous solvent. In particular a Li/LiBr, SeOC12 - Br2/C cell was constructed.
The anode of the cell was a lithium foil having a width of about 1.4 cm., a length of about 6.6 cm. and a thickness of about 0.056 cm. with a nickel current collector having an extending lead or tab cold welded on the lithium foil. The cathode was fabricated by providing a thin layer of carbon having a width of about 1.5 cm., a length of about 7.0 cm. and an approximate weight of from about 170 milligrams to about 190 milligrams and then by pressing the carbon layer on a thin expanded metal screen of stainless steel having an extending lead or tab. A separator in the form of a sheet of Celgard material also was provided and placed between the anode and cathode layers, whereupon the anode/separator/cathode assembly or combination was rolled or wound into a cylindrical configuration having an outer diameter of about 1.0 cm. and a height of about 2.0 cm. The resulting assembly was placed in a glass vial or other suitable container of appropriate size with the anode and cathode current collector leads extending out through the open end of the container. The depolarizer-electrolyte solution was prepared in the form of a O.lM solution of lithium bromide in a selenium oxychloride and bromine solution, the volume ration of selenium- oxychloride to bromine being 1:1 and the total volume of the solution being 2.0 ml.
~133V4~
1 The solution was injected or otherwise suitably introduced into the container, and then the open end of the container was sealed closed by a Teflon lined stopper or other suitable closure in a manner maintaining the spaced anode and cathode leads externally accessible for electrical connection. The laboratory cell had an open cirucit voltage of about 3.8 volts and then an initial load voltage of about 3.7 volts when discharged at room temperature under a constant load of 3.3 kilohms. After a fifty hour discharge period the load voltage was about 3.6 volts. The cell realized a total discharge capacity of approximately 94 milliampere hours to a 3.0 volt cutoff.
Table I presents discharge test data obtained from the test cell constructed according to Example I and from the laboratory cell according to the present invention described in Example II, both cells being discharged at room temperature under a constant load of 3.3 kilohms provided by a load resistor of that magnitude connected 20 across the cell terminals. ~$
113304~
1 Table I
Discharge Date For Cells Of Examples I and II
Discharge Time Measured Load Voltage In Volts Period In Hours Example I Example II
Example II
A laboratory cell according to the present invention was constructed including a lithium anode, a carbon cathode and an ionic conductive electrolytic solution comprising ~, 113304'9 1 a halogen dissolved in a non-aqueous solvent. In particular a Li/LiBr, SeOC12 - Br2/C cell was constructed.
The anode of the cell was a lithium foil having a width of about 1.4 cm., a length of about 6.6 cm. and a thickness of about 0.056 cm. with a nickel current collector having an extending lead or tab cold welded on the lithium foil. The cathode was fabricated by providing a thin layer of carbon having a width of about 1.5 cm., a length of about 7.0 cm. and an approximate weight of from about 170 milligrams to about 190 milligrams and then by pressing the carbon layer on a thin expanded metal screen of stainless steel having an extending lead or tab. A separator in the form of a sheet of Celgard material also was provided and placed between the anode and cathode layers, whereupon the anode/separator/cathode assembly or combination was rolled or wound into a cylindrical configuration having an outer diameter of about 1.0 cm. and a height of about 2.0 cm. The resulting assembly was placed in a glass vial or other suitable container of appropriate size with the anode and cathode current collector leads extending out through the open end of the container. The depolarizer-electrolyte solution was prepared in the form of a O.lM solution of lithium bromide in a selenium oxychloride and bromine solution, the volume ration of selenium- oxychloride to bromine being 1:1 and the total volume of the solution being 2.0 ml.
~133V4~
1 The solution was injected or otherwise suitably introduced into the container, and then the open end of the container was sealed closed by a Teflon lined stopper or other suitable closure in a manner maintaining the spaced anode and cathode leads externally accessible for electrical connection. The laboratory cell had an open cirucit voltage of about 3.8 volts and then an initial load voltage of about 3.7 volts when discharged at room temperature under a constant load of 3.3 kilohms. After a fifty hour discharge period the load voltage was about 3.6 volts. The cell realized a total discharge capacity of approximately 94 milliampere hours to a 3.0 volt cutoff.
Table I presents discharge test data obtained from the test cell constructed according to Example I and from the laboratory cell according to the present invention described in Example II, both cells being discharged at room temperature under a constant load of 3.3 kilohms provided by a load resistor of that magnitude connected 20 across the cell terminals. ~$
113304~
1 Table I
Discharge Date For Cells Of Examples I and II
Discharge Time Measured Load Voltage In Volts Period In Hours Example I Example II
4.0 3.45 6.0 3.42 10.0 3.~
20.0 3.65 1024.0 3.37 30.0 3.65 48.0 3-37 3.62 55.0 3.35 ~0.0 3.55 64.0 3.25 70.0 3.50 74.0 2.60 ~0.0 1.~0 3.38 2090.0 2.50 95.0 2.15 100.0 2.05 102.0 2.00 Fig. 1 is a graph of load voltage as a function of time further illustrating the data of Table I wherein curves 10 and 12 are plots of the discharge data for the cells of Examples I and II, respectively.
~13304~
1 It is noted that the discharge voltage of the cell of Example II is higher than that of the cell of Example I
throughout the operating life.
Example III
A test cell was constructed having a lithium anode, a carbon cathode and an electrolyte comprising lithium aluminum tetrachloride dissolved in thionyl chloride.
In particular, the anode of the cell was a lithium foil having a width of about 1.5 cm., a length of about 7.0 10 cm. and a thickness of about 0.05~ cm. with a nickel current collector having an extending lead or tab cold welded on the lithium foil. The cathode was fabricated by providing a quantity of carbon having a weight of about 0.25 gram and containing binder of Teflon material in an amount of approximately 5% by weight and spreading the carbon onto a nickel expanded metal element having a width of about 1.5 cm. and a length of about 7.0 cm. and including an extending lead or tab. A separator in the form t of a sheet of non-woven glass material was provided and 20 placed between the anode and cathode layers. The anode/
separator/cathode assembly or combination was wound into a cylindrical shape and inserted in a glass vial having an outer diameter of 1.3 cm. with the anode and cathode current collector leads extending out through the open end of the vial. The depolarizer-electrolyte solution was prepared comprising lithium aluminum 1133~4~
1 tetrachloride dissolved in thionyl chloride to provide a l.OM solution having a total volume of 2.Q ml. The solution was injected into the glass vial, and then the open end of the vial was sealed closed with a Teflon lined stopper in a manner maintaining the spaced anode and cathode leads externally accessible for electrical connection. The test cell had an open circuit voltage of 3.60 volts and was discharged at room temperature under a constant load of 182 ohms with the average current 10 drain rate being approximately 20 milliamperes. During discharge the cell had an initial load voltage of about 3.4 volts and a load voltage of about 3.3 volts after a 32 hour discharge period. The cell realized a total discharge capacity of approximately 650 milliampere hours to a 3.0 volt cutoff.
Example IV
A laboratory cell according to the present invention was constructed including a lithium anode, a carbon cathode and an ionic conductive electrolytic solution 20 comprising a halogen dissolved in a non-aqueous solvent.
In particular, a Li/LiAlC14, SOC12-Br2/C cell was constructed. The lithium anode, carbon cathode and anode/
separator/cathode combination were constructed in a manner identical to that of Example III. Tne depolarizer-electrolyte solution was prepared in the form of a 1.0~ solution of lithium aluminum tetrachloride in a thionyl chloride `~ f"
J ~`~
1 and bromine solution, there being 0.2 ml bromine and 1.8 thionyl chloride for a total volume of 2.0 ml. of the solution. The solution was injected into the glass vial which was then sealed in a manner similar to that of Example III. The cellhad an open circuit voltage of 3.80 + 0.05 volts and was discharged at room temperature (25 + 3C) under a constant load of 182 ohms with the average current drain rate being approximately 20 milliamperes.
During discharge the cell had an initial load voltage of about 3.8 volts and a load voltage of about 3.3 volts after a 32 hour discharge period. The cell realized a total discharge capacity of approximately 700 milliampere hours to a 3.0 volt cutoff.
Table II presents discharge test data obtained !
from the test cell constructed according to Example III
and from the laboratory cell according to the present invention described in Example IV, both cells being discharged at room temperature under a constant load of 182 ohms provided by a load resistor of that magnitude connected across the cell terminals.
1133~9 1 Table II
Discharge Data For Cells Of Examples III and IV
Discharge Time Measured Load Voltage In Volts Period In Hours Example III Example IV
1.0 3 37 3 75 4.0 3.35 3.70 10.0 3.32 3.60 14.0 3.30 3 ~5 1018.0 3.42 24.0 3.30 3.40 32.0 3.25 3.32 35.0 3.12 36.0 3.2 39 o 1.85 40.0 1.25 2.00 Fig. 2 is a graph of load voltage as a function of time further illustrating the date of Table II wherein curves 14 and 16 are plots of the discharge data for the cells of Examples III and IV, respectively. It is noted that the discharge voltage of the cell of Example IV is higher : than that of the cell of Example III throughout the operating life.
Example V
A laboratory cell according to the present invention was constructed including a lithium anode, a carbon cathode and an ionic conductive electrolytic solution comprising a halogen dissolved in a non-aqueous solvent. In particular, 1 a Li/LiAlC14, SGC12 - C12/C cell was constructed. The lithium anode and carbon cathode were constructed in a manner similar to that of Example III with the cathode of this example having a weight of from about 180 milligrams to about 200 milligrams. The separator was of Teflon material or, alternatively, a non-woven glass material commercially avialable under the name Dexiglas. The anode/
separator/cathode combination was rolled into a cylindrical shape and inserted in a glass vial in a manner identical to ', that of Exanple III. The depolarizer-electrolyte solution was prepared in the form of a 1.0 M solution of lithium aluminum tetrachloride in thionyl chloride saturated with chlorine at room temperature, the total volume of the solution being 2.0 milliliters. The solution was injected into the glass vial which was then sealed in a manner similar to that of Example III. The cell had an open circuit voltage of about ~,.0 volts and was discharged at room temperature under a constant load of 182 ohms provided by a load resistor of that magnitude connected across the cell terminals. The discharge test data obtained form the cell of Example V is presented in Table III.
()49 1 Table III
Discharge Data For Cell of Example V
Discharge Time In Hours ~easured Load Voltage In Volts 1.0 3.82 3.0 3.77 4.0 3.25 17.0 3-07 19.0 2.67 Fig. 3 is a graph of load voltage as a function of time 10 wherein curve 18 further illustrates the discharge data of Table III.
Example VI
A prototype cell according to the present invention was constructed including a lithium anode, a carbon cathode and an ionic conductive electrolytic solution comprising a halogen dissolved in a non-aqueous solvent. In particular, a Li/LiAlC14, SOC12 - Br2/C cell was constructed approximately according to "AA" size specifications. In particular, the dimensions of the prototype cell were 1.35 cm. outer diameter 20 by 4.70 cm. length, the casing was 304 stainless steel and the cell was hermetically sealed using a glass-to metal seal which was laser welded to the casing. The anode was a lithium sheet having a width of about 4.0 cm., a length of about 5.6 cm. and a weight of about 739 milligrams with a nic~el current collector cold welded on the lithium foil. The cathode was a carbon sheet or layer having a width of about 4.0 cm., a length 1 of about 6.0 cm. and a weight of about 7al milligrams which is pressed onto a thin expanded metal screen of stainless steel. Alternatively, the cathode could be carbon on an expanded nickel screen. A separator in the form of a sheet of non-woven glass material also was provided and placed between the anode and cathode layers, whereupon the anode/separator/cathode combination was rolled or wound into a cylindrical configuration in a manner similar to that of the preceding examples and placed in the size "AA" cell casing. The depolarizer-electrolyte solution was prepared in the form of a 1.0 ~ solution of lithium aluminum tetrachloride in a thionyl chloride and bromine solution, the amount by volume of bromine being 10~/o and the total volume of the solution being approximately 4 cc.
The solution was injected or otherwise suitable introduced into the casing. The prototype cell was hermetically sealed by welding the glass-to-metal seal to the cell case. Prior to sealing, electrical connections were made from the cell case and insulated terminal to the cell electrodes or current collectors within the casing in a suitable manner. The prototype cell had an open voltage of about 3.~ volts and an initial load voltage of about 3.7 volts when discharged at room temperature under a constant load of 68.1 ohms with an average current drain of about 50 milliamperes.
After a 35 hour discharge period the load voltage was about 3.3 volts. The cell realized a total discharye capacity of approximately 1.85 ampere hours to a 3.0 volt cutoff.
~1330~9 1 Example VII
A test cell was constructed having a lithium anode, a carbon cathode and a electrolyte comprising lithium aluminum tetrachloride dissolved in thionyl chloride. In particular the anode, cathode and separator were similar to those of Example VI, with the anode having a width of about 4.0 cm., a length of about 6.0 cm. and a weight of about 817 milligrams. The anode/separator/cathode combination was wound and inserted in a size "AA" casing in a manner similar to that of Example VI. A depolarizer-electrolyte solution was prepared comprising lithium aluminum tetrachloride dissolved in thionyl chloride to provide a 1.0 M solution having a volume of approximately 4cc. The solution was injected or otherwise introduced into the casing which then was sealed closed, all in a manner - similar to that of Example VI. The test cell had an open circuit voltage of about 3.6 volts and an initial load voltage of about 3.4 volts when discharged at room temperature under a constant load of 75 ohms with an average drain of about 45 milliamperes. After a 35 hour discharge period the load voltage was about 3.2 volts. The cell realized a total discharge capacity of approximately 1.69 ampere hours to a 3.0 volt cutoff.
Table IV presents discharge test data obtained from the prototype cell constructed according to Example VI and from the test cell constructed according to Example VII.
1133~)49 Table IV
Dlscharge Data For Cells Of Exsmples VI and VII
Dlscharge Timc Measured Load Voltage In Volt~
Perlod In Rours Example VI _ ExsmDle VII
1.0 3.67, 3.37 2.0 3.
20.0 3 50 24.0 3.30 30,0 3,47 3.25 35.0 3.25 36.0 3.10 3.20 Flg. 4 18 a graph of losd voltage as a function of time further illustratlng the data of Table IV wherein curves 20 and 22 are plots of the dl~charge data for the cells of Examples VI snd VII, respectively. It i8 noted that the dlscn~rge voltnge of the prototype cell of Example VI is higher than that of the test cell of Exa~ple VII throughout substantially the entlre operating life~
Flg~. 5-8 illustrate additlonal tests conducted on the Li/Br2 + SOC12 "M" prototype cell of Example VI. In particular, Fig. 5 shows the discharge characterist.lc~
of the Ll/Br2 + SOC12 "M " prototype cell at room temperature (25 + 3~C) wherein the curves 24, 26, 28, and 30 are plot~ of the di~charge data at con~tant load3 of 332 oh~s, 182 ohms, 75 ohms and 33 ohm~, respectlvely. As in all of tho preceding examples, the loads are provlded by a load resistor of the indio~ed value connected across ' - -22-11330~
the cell termln~l8. As expected, the reallzsble cspaclty of the cell was found ~o be a functlon of the discharge rate. A capaclty of more than 2.l ampere hours was realized to a cutoff of 2.0 volts at an average rate belcw 20 mllllamperes under n 182 ohm load. However, the realized capsclty wa~ found to be much le~s st hlgher current draln rates, L.e. 1.6 ampere ho~rs under a 75 ohm load and about l.3 ampere hours under a 33 ohm load. Based upon the average loHd voltage and the realized capaclty, lt follows that the prototype "M "
Li/Br2 ~ SOC12 cell ha3 a practlcal volumetrlc energy denslty ranglng between 0.7 and l.l watt-hours per cublc centimeter in the dlscharge rate between 10 and 100 mllliamperes.
The energy denslty at a lower dlscharge rate would be much higher as shown ln Flg. 6. In partlcular, Flg. 6 lllustrates the addltlonal low rate dlscharge capaclty of the Ll/Br2 + SOC12 "M " prototype cells whlch had been dlscharged to the 2 volt cutoff under a di~charge rate between 10 and 20 mllllampere~. In Flg.
6, curve 32 lllustrates dlscharge data for a cell under 182 ohm~ load to a 2.0 vol~ cutoff with 2.1 ampere houra delivered, and curve 34 illustrates dlscharge data for a cell under a 332 ohm load to a 2.0 volt cutoff wlth 2.1 ampere houra delivered. After cutoff both cells were dl0charged under a 140 kllohm load. As lllustsated ln Flg. 6, te~t cells whlch have been dischArged to the 2.0 volt cutoff under loads of 182 ohm~ or 332 ohma contlnued to exhiblt a cell voltage of 3.4 volt~ under a 140 kilohm lo~d.
Flgs. 7 and 8 llluatrate diAcharge data from the prototype cells of the ~ame exAmple dl~ch~rged at hlgh and low temperature~, respectlvely. In partic~sr, Flg.
7 presents dlscharge characterlstlcs of the L~/Br2 +
SOC12 "AA" prototype cells at 60 + 3 Centlgrade. The curves 36, 38, 40, 42 and 44 are plot~ of dlscharge dats under load reslstances of 705 ohm~, 341 ohma, 182 ohm~, 75 ohm~, ~nd 50 ohma, respectlvely. It was found th~t at 60 Centlgrade the realized capaclty was somewhat lGwer than at room temperature under a slmllar load. Flg. 8 lllustrates dlscharge charac~ristlcs of the Ll~Br2 + SOC12 "AA" prototype cells st -40 + 3 Centlgrade. In partlculsr, the curves 48, 50, 52, 54 and 56 ln Flg. 8 are plots of dlscharge data under load reslstances of 681 ohms, 332 ohms, 182 ohms, 75 ohmA, and 33 ohms, respectlvely. It was found that both the low voltage and therealized capacity are conslderably lower at -40 Centlgrsde. Furthermore, a voltage delay was clearly noted at the beglnnlng of the dlscharge teYt at -40C, e~pecially at hlgh currents. Nonetheless, a practlcal volumatlc energy density of 0.6 watt hour~ per cublc centimeter was realized at about 10 m~lliamperes at -40C.
~3304,9 EXAMPLE VIII
A ~i/LiAlC14, SOC12, - C12 cell of the type described in Example V was constructed approximately to "AA"
size specifications as set forth in Example VI. The prototype cell had an open circuit voltage of about 3.9 volts, and the cell realized a total discharge capacity of approximately 2.0 ampere hours when discharged under a 20 ohm load at room temperature to a 2.0 volt cutoff.
EXAMPLE IX
-- ----A Li/LiAlC14, SOC12 - BrCl cell was constructed to approximately "AA" size specifications as described in Example VI. The prototype cell had an open circuit voltage of about 3.9 volts, and the cell realized a total discharge capaicty of approximately 2.1 ampere hours when discharged under a 182 ohm load at room temperature to a 2.0 volt cutoff. In Fig. 9 the curve 58 is a plot of a cell voltage against capacity illustrating the discharge characteristics of the cell under a 182 ohm load.
It is therefore apparent that the present invention accomplishes its intended objects. While several embodiments of the present invention have been described in detail, this is for the purpose of illustration, not limitation.
20.0 3.65 1024.0 3.37 30.0 3.65 48.0 3-37 3.62 55.0 3.35 ~0.0 3.55 64.0 3.25 70.0 3.50 74.0 2.60 ~0.0 1.~0 3.38 2090.0 2.50 95.0 2.15 100.0 2.05 102.0 2.00 Fig. 1 is a graph of load voltage as a function of time further illustrating the data of Table I wherein curves 10 and 12 are plots of the discharge data for the cells of Examples I and II, respectively.
~13304~
1 It is noted that the discharge voltage of the cell of Example II is higher than that of the cell of Example I
throughout the operating life.
Example III
A test cell was constructed having a lithium anode, a carbon cathode and an electrolyte comprising lithium aluminum tetrachloride dissolved in thionyl chloride.
In particular, the anode of the cell was a lithium foil having a width of about 1.5 cm., a length of about 7.0 10 cm. and a thickness of about 0.05~ cm. with a nickel current collector having an extending lead or tab cold welded on the lithium foil. The cathode was fabricated by providing a quantity of carbon having a weight of about 0.25 gram and containing binder of Teflon material in an amount of approximately 5% by weight and spreading the carbon onto a nickel expanded metal element having a width of about 1.5 cm. and a length of about 7.0 cm. and including an extending lead or tab. A separator in the form t of a sheet of non-woven glass material was provided and 20 placed between the anode and cathode layers. The anode/
separator/cathode assembly or combination was wound into a cylindrical shape and inserted in a glass vial having an outer diameter of 1.3 cm. with the anode and cathode current collector leads extending out through the open end of the vial. The depolarizer-electrolyte solution was prepared comprising lithium aluminum 1133~4~
1 tetrachloride dissolved in thionyl chloride to provide a l.OM solution having a total volume of 2.Q ml. The solution was injected into the glass vial, and then the open end of the vial was sealed closed with a Teflon lined stopper in a manner maintaining the spaced anode and cathode leads externally accessible for electrical connection. The test cell had an open circuit voltage of 3.60 volts and was discharged at room temperature under a constant load of 182 ohms with the average current 10 drain rate being approximately 20 milliamperes. During discharge the cell had an initial load voltage of about 3.4 volts and a load voltage of about 3.3 volts after a 32 hour discharge period. The cell realized a total discharge capacity of approximately 650 milliampere hours to a 3.0 volt cutoff.
Example IV
A laboratory cell according to the present invention was constructed including a lithium anode, a carbon cathode and an ionic conductive electrolytic solution 20 comprising a halogen dissolved in a non-aqueous solvent.
In particular, a Li/LiAlC14, SOC12-Br2/C cell was constructed. The lithium anode, carbon cathode and anode/
separator/cathode combination were constructed in a manner identical to that of Example III. Tne depolarizer-electrolyte solution was prepared in the form of a 1.0~ solution of lithium aluminum tetrachloride in a thionyl chloride `~ f"
J ~`~
1 and bromine solution, there being 0.2 ml bromine and 1.8 thionyl chloride for a total volume of 2.0 ml. of the solution. The solution was injected into the glass vial which was then sealed in a manner similar to that of Example III. The cellhad an open circuit voltage of 3.80 + 0.05 volts and was discharged at room temperature (25 + 3C) under a constant load of 182 ohms with the average current drain rate being approximately 20 milliamperes.
During discharge the cell had an initial load voltage of about 3.8 volts and a load voltage of about 3.3 volts after a 32 hour discharge period. The cell realized a total discharge capacity of approximately 700 milliampere hours to a 3.0 volt cutoff.
Table II presents discharge test data obtained !
from the test cell constructed according to Example III
and from the laboratory cell according to the present invention described in Example IV, both cells being discharged at room temperature under a constant load of 182 ohms provided by a load resistor of that magnitude connected across the cell terminals.
1133~9 1 Table II
Discharge Data For Cells Of Examples III and IV
Discharge Time Measured Load Voltage In Volts Period In Hours Example III Example IV
1.0 3 37 3 75 4.0 3.35 3.70 10.0 3.32 3.60 14.0 3.30 3 ~5 1018.0 3.42 24.0 3.30 3.40 32.0 3.25 3.32 35.0 3.12 36.0 3.2 39 o 1.85 40.0 1.25 2.00 Fig. 2 is a graph of load voltage as a function of time further illustrating the date of Table II wherein curves 14 and 16 are plots of the discharge data for the cells of Examples III and IV, respectively. It is noted that the discharge voltage of the cell of Example IV is higher : than that of the cell of Example III throughout the operating life.
Example V
A laboratory cell according to the present invention was constructed including a lithium anode, a carbon cathode and an ionic conductive electrolytic solution comprising a halogen dissolved in a non-aqueous solvent. In particular, 1 a Li/LiAlC14, SGC12 - C12/C cell was constructed. The lithium anode and carbon cathode were constructed in a manner similar to that of Example III with the cathode of this example having a weight of from about 180 milligrams to about 200 milligrams. The separator was of Teflon material or, alternatively, a non-woven glass material commercially avialable under the name Dexiglas. The anode/
separator/cathode combination was rolled into a cylindrical shape and inserted in a glass vial in a manner identical to ', that of Exanple III. The depolarizer-electrolyte solution was prepared in the form of a 1.0 M solution of lithium aluminum tetrachloride in thionyl chloride saturated with chlorine at room temperature, the total volume of the solution being 2.0 milliliters. The solution was injected into the glass vial which was then sealed in a manner similar to that of Example III. The cell had an open circuit voltage of about ~,.0 volts and was discharged at room temperature under a constant load of 182 ohms provided by a load resistor of that magnitude connected across the cell terminals. The discharge test data obtained form the cell of Example V is presented in Table III.
()49 1 Table III
Discharge Data For Cell of Example V
Discharge Time In Hours ~easured Load Voltage In Volts 1.0 3.82 3.0 3.77 4.0 3.25 17.0 3-07 19.0 2.67 Fig. 3 is a graph of load voltage as a function of time 10 wherein curve 18 further illustrates the discharge data of Table III.
Example VI
A prototype cell according to the present invention was constructed including a lithium anode, a carbon cathode and an ionic conductive electrolytic solution comprising a halogen dissolved in a non-aqueous solvent. In particular, a Li/LiAlC14, SOC12 - Br2/C cell was constructed approximately according to "AA" size specifications. In particular, the dimensions of the prototype cell were 1.35 cm. outer diameter 20 by 4.70 cm. length, the casing was 304 stainless steel and the cell was hermetically sealed using a glass-to metal seal which was laser welded to the casing. The anode was a lithium sheet having a width of about 4.0 cm., a length of about 5.6 cm. and a weight of about 739 milligrams with a nic~el current collector cold welded on the lithium foil. The cathode was a carbon sheet or layer having a width of about 4.0 cm., a length 1 of about 6.0 cm. and a weight of about 7al milligrams which is pressed onto a thin expanded metal screen of stainless steel. Alternatively, the cathode could be carbon on an expanded nickel screen. A separator in the form of a sheet of non-woven glass material also was provided and placed between the anode and cathode layers, whereupon the anode/separator/cathode combination was rolled or wound into a cylindrical configuration in a manner similar to that of the preceding examples and placed in the size "AA" cell casing. The depolarizer-electrolyte solution was prepared in the form of a 1.0 ~ solution of lithium aluminum tetrachloride in a thionyl chloride and bromine solution, the amount by volume of bromine being 10~/o and the total volume of the solution being approximately 4 cc.
The solution was injected or otherwise suitable introduced into the casing. The prototype cell was hermetically sealed by welding the glass-to-metal seal to the cell case. Prior to sealing, electrical connections were made from the cell case and insulated terminal to the cell electrodes or current collectors within the casing in a suitable manner. The prototype cell had an open voltage of about 3.~ volts and an initial load voltage of about 3.7 volts when discharged at room temperature under a constant load of 68.1 ohms with an average current drain of about 50 milliamperes.
After a 35 hour discharge period the load voltage was about 3.3 volts. The cell realized a total discharye capacity of approximately 1.85 ampere hours to a 3.0 volt cutoff.
~1330~9 1 Example VII
A test cell was constructed having a lithium anode, a carbon cathode and a electrolyte comprising lithium aluminum tetrachloride dissolved in thionyl chloride. In particular the anode, cathode and separator were similar to those of Example VI, with the anode having a width of about 4.0 cm., a length of about 6.0 cm. and a weight of about 817 milligrams. The anode/separator/cathode combination was wound and inserted in a size "AA" casing in a manner similar to that of Example VI. A depolarizer-electrolyte solution was prepared comprising lithium aluminum tetrachloride dissolved in thionyl chloride to provide a 1.0 M solution having a volume of approximately 4cc. The solution was injected or otherwise introduced into the casing which then was sealed closed, all in a manner - similar to that of Example VI. The test cell had an open circuit voltage of about 3.6 volts and an initial load voltage of about 3.4 volts when discharged at room temperature under a constant load of 75 ohms with an average drain of about 45 milliamperes. After a 35 hour discharge period the load voltage was about 3.2 volts. The cell realized a total discharge capacity of approximately 1.69 ampere hours to a 3.0 volt cutoff.
Table IV presents discharge test data obtained from the prototype cell constructed according to Example VI and from the test cell constructed according to Example VII.
1133~)49 Table IV
Dlscharge Data For Cells Of Exsmples VI and VII
Dlscharge Timc Measured Load Voltage In Volt~
Perlod In Rours Example VI _ ExsmDle VII
1.0 3.67, 3.37 2.0 3.
20.0 3 50 24.0 3.30 30,0 3,47 3.25 35.0 3.25 36.0 3.10 3.20 Flg. 4 18 a graph of losd voltage as a function of time further illustratlng the data of Table IV wherein curves 20 and 22 are plots of the dl~charge data for the cells of Examples VI snd VII, respectively. It i8 noted that the dlscn~rge voltnge of the prototype cell of Example VI is higher than that of the test cell of Exa~ple VII throughout substantially the entlre operating life~
Flg~. 5-8 illustrate additlonal tests conducted on the Li/Br2 + SOC12 "M" prototype cell of Example VI. In particular, Fig. 5 shows the discharge characterist.lc~
of the Ll/Br2 + SOC12 "M " prototype cell at room temperature (25 + 3~C) wherein the curves 24, 26, 28, and 30 are plot~ of the di~charge data at con~tant load3 of 332 oh~s, 182 ohms, 75 ohms and 33 ohm~, respectlvely. As in all of tho preceding examples, the loads are provlded by a load resistor of the indio~ed value connected across ' - -22-11330~
the cell termln~l8. As expected, the reallzsble cspaclty of the cell was found ~o be a functlon of the discharge rate. A capaclty of more than 2.l ampere hours was realized to a cutoff of 2.0 volts at an average rate belcw 20 mllllamperes under n 182 ohm load. However, the realized capsclty wa~ found to be much le~s st hlgher current draln rates, L.e. 1.6 ampere ho~rs under a 75 ohm load and about l.3 ampere hours under a 33 ohm load. Based upon the average loHd voltage and the realized capaclty, lt follows that the prototype "M "
Li/Br2 ~ SOC12 cell ha3 a practlcal volumetrlc energy denslty ranglng between 0.7 and l.l watt-hours per cublc centimeter in the dlscharge rate between 10 and 100 mllliamperes.
The energy denslty at a lower dlscharge rate would be much higher as shown ln Flg. 6. In partlcular, Flg. 6 lllustrates the addltlonal low rate dlscharge capaclty of the Ll/Br2 + SOC12 "M " prototype cells whlch had been dlscharged to the 2 volt cutoff under a di~charge rate between 10 and 20 mllllampere~. In Flg.
6, curve 32 lllustrates dlscharge data for a cell under 182 ohm~ load to a 2.0 vol~ cutoff with 2.1 ampere houra delivered, and curve 34 illustrates dlscharge data for a cell under a 332 ohm load to a 2.0 volt cutoff wlth 2.1 ampere houra delivered. After cutoff both cells were dl0charged under a 140 kllohm load. As lllustsated ln Flg. 6, te~t cells whlch have been dischArged to the 2.0 volt cutoff under loads of 182 ohm~ or 332 ohma contlnued to exhiblt a cell voltage of 3.4 volt~ under a 140 kilohm lo~d.
Flgs. 7 and 8 llluatrate diAcharge data from the prototype cells of the ~ame exAmple dl~ch~rged at hlgh and low temperature~, respectlvely. In partic~sr, Flg.
7 presents dlscharge characterlstlcs of the L~/Br2 +
SOC12 "AA" prototype cells at 60 + 3 Centlgrade. The curves 36, 38, 40, 42 and 44 are plot~ of dlscharge dats under load reslstances of 705 ohm~, 341 ohma, 182 ohm~, 75 ohm~, ~nd 50 ohma, respectlvely. It was found th~t at 60 Centlgrade the realized capaclty was somewhat lGwer than at room temperature under a slmllar load. Flg. 8 lllustrates dlscharge charac~ristlcs of the Ll~Br2 + SOC12 "AA" prototype cells st -40 + 3 Centlgrade. In partlculsr, the curves 48, 50, 52, 54 and 56 ln Flg. 8 are plots of dlscharge data under load reslstances of 681 ohms, 332 ohms, 182 ohms, 75 ohmA, and 33 ohms, respectlvely. It was found that both the low voltage and therealized capacity are conslderably lower at -40 Centlgrsde. Furthermore, a voltage delay was clearly noted at the beglnnlng of the dlscharge teYt at -40C, e~pecially at hlgh currents. Nonetheless, a practlcal volumatlc energy density of 0.6 watt hour~ per cublc centimeter was realized at about 10 m~lliamperes at -40C.
~3304,9 EXAMPLE VIII
A ~i/LiAlC14, SOC12, - C12 cell of the type described in Example V was constructed approximately to "AA"
size specifications as set forth in Example VI. The prototype cell had an open circuit voltage of about 3.9 volts, and the cell realized a total discharge capacity of approximately 2.0 ampere hours when discharged under a 20 ohm load at room temperature to a 2.0 volt cutoff.
EXAMPLE IX
-- ----A Li/LiAlC14, SOC12 - BrCl cell was constructed to approximately "AA" size specifications as described in Example VI. The prototype cell had an open circuit voltage of about 3.9 volts, and the cell realized a total discharge capaicty of approximately 2.1 ampere hours when discharged under a 182 ohm load at room temperature to a 2.0 volt cutoff. In Fig. 9 the curve 58 is a plot of a cell voltage against capacity illustrating the discharge characteristics of the cell under a 182 ohm load.
It is therefore apparent that the present invention accomplishes its intended objects. While several embodiments of the present invention have been described in detail, this is for the purpose of illustration, not limitation.
Claims (36)
1. An electrochemical cell having an anode of a metal above hydrogen in the electromotive series which is electrochemically oxidizable to form metal ions in said cell upon discharge to generate electron flow in an external electrical circuit connected to said cell and a cathode of electronically conductive material and characterized by an ionic conductive electrolytic solution operatively associated with said anode and said cathode, said electrolytic solution consisting essentially of a first component selected from the group consisting of halogens, interhalogens and mixtures thereof dissolved in a second component in the form of a non-aqueous solvent or a mixture of non-aqueous solvents, said first component serving as a soluble depolarizer and as a cosolvent in said cell.
2. An electrochemical cell according to claim 1, wherein said anode comprises a metal selected from the group consisting of alkali metals and alkaline earth metals.
3. An electrochemical cell according to claim 1, wherein said cathode material is electroactive.
4. An electrochemical cell according to claim 1, wherein said cathode material contains carbon.
5. An electrochemical cell according to claim 1, wherein said non-aqueous solvent serves as a soluble depolarizer and as a cosolvent in said cell.
6. An electrochemical cell according to claim 1, wherein said non-aqueous solvent is an organic solvent which is substantially inert to the material of said anode and of said cathode.
7. An electrochemical cell according to claim 1, wherein said non-aqueous solvent is an inorganic solvent which serves as both a solvent and as a depolarizer in said cell.
8. An electrochemical cell according to claim 1, wherein said solvent mixture comprises organic solvents.
9. An electrochemical cell according to claim 1, wherein said solvent mixture comprises inorganic solvents.
10. An electrochemical cell according to claim 1, wherein said solvent mixture comprises both organic and inorganic solvents.
11. An electrochemical cell according to claim 1, further including a metal salt dissolved in said electro-lytic solution to enhance the ionic conduction thereof.
12. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises bromine dissolved in selenium oxychloride.
13. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises chlorine dissolved in selenium oxychloride.
14. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises bromine chloride dissolved in selenium oxychloride.
15. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises a mixture of chlorine and bromine dissolved in selenium oxychloride.
16. An electrochemical cell according to claim 12, further including lithium bromide dissolved in said solution of bromine and selenium ocychloride.
17. An electrochemical cell according to claim 13, further including lithium bromide dissolved in said solution of chlorine and selenium oxychloride.
18. An electrochemical cell according to claim 14, further including lithium bromide dissolved in said solution of bromine chloride in selenium oxychloride.
19. An electrochemical cell according to claim 15, further including lithium bromide dissolved in said solution of chlorine and bromine in selenium oxychloride.
20. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises bromine dissolved in thionyl chloride.
21. An electrochemical cell according to claim 20, further including lithium aluminum tetrachloride dissolved in said solution of bromine and thionyl chloride.
22. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises chlorine dissolved in thionyl chloride.
23. An electrochemical cell according to claim 22, further including lithium aluminum tetrachloride dissolved in said solution of chlorine and thionyl chloride.
24. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises bromine chloride dissolved in thionyl chloride.
25. An electrochemical cell according to claim 24, further including lithium aluminum tetrachloride dissolved in said solution of bromine chloride and thionyl chloride.
26. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises a mixture of chlorine and bromine dissolved in thionyl chloride.
27. An electrochemical cell according to claim 26, further including lithium aluminum tetrachloride dissolved in said solution of chlorine and bromine in thionyl chloride.
28. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises chlorine dissolved in sulfuryl chloride.
29. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises bromine dissolved in sulfuryl chloride.
30. An electrochemical cell according to claim 1, herein said anode comprises lithium and said electrolytic solution comprises bromine chloride dissolved in sulfuryl chloride.
31. An electrochemical cell according to claim 1, wherein said anode comprises lithium and said electrolytic solution comprises a mixture of bromine and chlorine dissolved in sulfuryl chloride.
32. An electrochemical cell comprising a lithium anode, a carbon cathode and a solution of lithium aluminum tetrachloride in a mixture of thionyl chloride and bromine serving as the depolarizer and electrolyte of said cell.
33. An electrochemical cell comprising a lithium anode, a carbon cathode and a solution of lithium aluminum tetrachloride in a mixture of thionyl chloride and bromine chloride serving as the depolarizer and electrolyte of said cell.
34. An electrochemcial cell comprising an anode selected from the group consisting of alkali metals, alkaline earth metals and intermetallic compounds including alkali metals and alkaline earth metals, a cathode of electronically conductive material, and an ionic conductive electrolytic solution operatively associated with said anode and said cathode, said electrolytic solution consisting essentially of a first component selected from the group consisting of halogens, interhalogens and mixtures thereof dissolved in a second component in the form of a non-aqueous solvent selected from the group consisting of organic solvents which are substantially inert to the materials of said anode and said cathode, inorganic solvents which can serve as both a solvent and a depolarizer in said cell and mixtures thereof, said first component serving as a soluble depolarizer and as a cosolvent in said cell.
35. An electrochemical cell according to claim 34, further including a metal salt dissolved in said electrolytic solution to enhance the ionic conductivity thereof.
36. An electrochemical cell according to claim 35, wherein the metal of said salt comprises lithium.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US6471579A | 1979-08-08 | 1979-08-08 | |
| US64,715 | 1979-08-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1133049A true CA1133049A (en) | 1982-10-05 |
Family
ID=22057813
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA347,514A Expired CA1133049A (en) | 1979-08-08 | 1980-03-12 | Electrochemical cell having mixed soluble depolarizer including halogens and interhalogens |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5626371A (en) |
| AU (1) | AU541987B2 (en) |
| CA (1) | CA1133049A (en) |
| DE (1) | DE3020198A1 (en) |
| FR (1) | FR2463516B1 (en) |
| GB (1) | GB2056752B (en) |
| IL (1) | IL59591A (en) |
| MX (1) | MX153889A (en) |
| NL (1) | NL190566C (en) |
| SE (1) | SE8001944L (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4246327A (en) * | 1979-10-01 | 1981-01-20 | Medtronic, Inc. | High energy-density battery system |
| FR2593968B1 (en) * | 1986-02-04 | 1994-12-09 | Accumulateurs Fixes | PRIMABLE BATTERY IMPLEMENTING THE LI / SO2 CL2 TORQUE |
| DE3733812A1 (en) * | 1987-10-07 | 1989-06-15 | Sonnenschein Lithium Gmbh | ELECTROLYT FOR ACTIVATIVE LI CELLS |
| FR2663467A1 (en) * | 1990-06-14 | 1991-12-20 | Commissariat Energie Atomique | CELL OF WHICH THE ANODE IS AN ALKALINE OR ALKALINE-EARTH METAL AND OF WHICH THE POSITIVE ACTIVE MATERIAL IS LIQUID. |
| FR2674687B1 (en) * | 1991-03-26 | 1997-01-03 | Alsthom Cge Alcatel | LITHIUM / BROMINE TRIFLUORIDE ELECTROCHEMICAL GENERATOR. |
| FR2674686B1 (en) * | 1991-03-26 | 1996-12-13 | Alsthom Cge Alcatel | LITHIUM / BROMINE TRIFLUORIDE ELECTROCHEMICAL GENERATOR, INTENDED TO BE DISCHARGED AFTER PRIMING AND STORAGE. |
| US6410181B1 (en) * | 1999-05-05 | 2002-06-25 | Wilson Greatbatch Ltd. | High temperature lithium oxyhalide electrochemical cell |
| CA2353765A1 (en) * | 2000-08-07 | 2002-02-07 | Paul W. Krehl | High voltage electrochemical cell capable of operating at extremely low temperatures |
| JP5810954B2 (en) * | 2012-02-09 | 2015-11-11 | 株式会社豊田中央研究所 | Non-aqueous battery |
| JPWO2021199676A1 (en) * | 2020-03-31 | 2021-10-07 |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE793372A (en) * | 1971-12-27 | 1973-06-27 | Union Carbide Corp | NON-AQUEOUS ELECTRO-CHEMICAL BATTERY |
| US4444855A (en) * | 1974-05-29 | 1984-04-24 | Union Carbide Corporation | Non-aqueous electrochemical cell |
| DE2611901C3 (en) * | 1975-03-31 | 1980-05-22 | Union Carbide Corp., New York, N.Y. (V.St.A.) | Anhydrous galvanic cell |
-
1980
- 1980-03-12 CA CA347,514A patent/CA1133049A/en not_active Expired
- 1980-03-12 IL IL59591A patent/IL59591A/en unknown
- 1980-03-12 SE SE8001944A patent/SE8001944L/en not_active Application Discontinuation
- 1980-03-31 FR FR8007163A patent/FR2463516B1/en not_active Expired
- 1980-04-22 GB GB8013144A patent/GB2056752B/en not_active Expired
- 1980-05-28 DE DE19803020198 patent/DE3020198A1/en active Granted
- 1980-07-26 JP JP10302080A patent/JPS5626371A/en active Granted
- 1980-08-06 NL NLAANVRAGE8004478,A patent/NL190566C/en not_active IP Right Cessation
- 1980-08-07 MX MX183493A patent/MX153889A/en unknown
- 1980-08-07 AU AU61152/80A patent/AU541987B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| NL190566C (en) | 1994-04-18 |
| DE3020198C2 (en) | 1991-02-07 |
| FR2463516A1 (en) | 1981-02-20 |
| AU541987B2 (en) | 1985-01-31 |
| NL8004478A (en) | 1981-02-10 |
| JPH0251221B2 (en) | 1990-11-06 |
| DE3020198A1 (en) | 1981-02-26 |
| GB2056752B (en) | 1983-06-02 |
| GB2056752A (en) | 1981-03-18 |
| MX153889A (en) | 1987-02-09 |
| IL59591A0 (en) | 1980-06-30 |
| IL59591A (en) | 1983-07-31 |
| JPS5626371A (en) | 1981-03-13 |
| SE8001944L (en) | 1981-02-09 |
| FR2463516B1 (en) | 1988-01-29 |
| NL190566B (en) | 1993-11-16 |
| AU6115280A (en) | 1981-02-12 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |