CA1039349A - Spot-welded fibrous separator for battery - Google Patents
Spot-welded fibrous separator for batteryInfo
- Publication number
- CA1039349A CA1039349A CA231,219A CA231219A CA1039349A CA 1039349 A CA1039349 A CA 1039349A CA 231219 A CA231219 A CA 231219A CA 1039349 A CA1039349 A CA 1039349A
- Authority
- CA
- Canada
- Prior art keywords
- fibres
- separator material
- separator
- textile fabric
- thermoplastic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/05—Interconnection of layers the layers not being connected over the whole surface, e.g. discontinuous connection or patterned connection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/02—Layered products comprising a layer of synthetic resin in the form of fibres or filaments
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/34—Layered products comprising a layer of synthetic resin comprising polyamides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
- B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
- B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/417—Polyolefins
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/423—Polyamide resins
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/44—Fibrous material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
- H01M50/494—Tensile strength
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/02—Synthetic macromolecular fibres
- B32B2262/0253—Polyolefin fibres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/02—Synthetic macromolecular fibres
- B32B2262/0261—Polyamide fibres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/02—Synthetic macromolecular fibres
- B32B2262/0276—Polyester fibres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2457/00—Electrical equipment
- B32B2457/04—Insulators
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Cell Separators (AREA)
Abstract
A separator material for electrolytic cells and particularly for storage batteries comprising, a non-woven textile fabric of thermoplastic fibres and/or endless threads of thermoplastic which are themselves electrolyte-resistant, and in which the separator material is consolidated by spot welds through the material. The spot welds occupy about 2 to 40% of the total surface area of the consolidated material. Textile fabric separators consisting of one or more of a polyolefin, polyamide, polycarbonate and polyester fibres, or mixtures, or heterofilament fibres of these materials are described. The surface of the consolidated material may be profiled by employing two layers of non-woven textile material and inserting threads in the intervening spaces between the two layers and the spot welds.
Description
1~3~3~9 1 The invention concerns the use of a~non-woven textile fabric of electrolyte-resistant thermoplastic fibres and/or endless threads as a separator material for batteries and electroytic cells.
Storage batteries are known to comprise a multiplicity of alternate positive and negative electrodes immersed in a fluid electrolyte. In order to prevent contact between positive and negative electrodes, and hence an undesirable short circuit flow of current within the battery, the electrodes are insulated from one another by separators. The separators thus have the task of preventing the electrodes from coming into electrical conducting contact with one another, but without substantially hindering the passage of ions in the electrolyte.
A suitable separator material must therefore meet numerous require-ments. It must be stable in the presence of the electrolyte and resist oxidation, and it must have a definite weight per unit area, precise thickness and high tensile strength. It must be easily wetted by the electrolyte, which it must absorb quickly, and must have a high capillarity.
For this purpose large pore volume, or labyrinth structure is desirable with small, uniform pore diameters. The material must show low electrical resistance in the electrolyte, and must also be flexible and supple.
From the standpoint solely of function, a porous, non-conducting ceramic material suggests itself as a simple solution; however, such a separator at the very least does not have the necessary flexibility.
Good flexibility and rollability of the separator, material is necessary, especially for the manufacture of tubular storage batteries. In such instance both the positive and negative electrodes consist of thin plates which can be rolled. The separator material is therefore inserted between them, and it also must be capable of being rolled. After a strip comprising a positive and negative electrode and a separator has been rolled, the three-layer strip i~ inserted into a tubular housing filled with electrolyte, and the electrolyte is rapidly absorbed in sufficient quantity by the separator material and is retained in its pores. The separator material must therefore ~3g349 1 be stable in the presence of electrolyte flui~d being used and must be able to adhere closely to the positive and negative electrodes. It is also deslrable for the separator material to possess a labyrinth structure to provide a filtering action for solid particles separating from the electrodes.
More particularly in accordance with the invention there is provided, a separator material for electrolytic cells comprising, a non-woven textile fabric of electrolyte-resistant thermoplastic fibres and/or endless threads, -~
spot welds consolidating the textile fabric, the spot welds occupying about ~ to 40% of the total surface area of the consolidated material. Preferably, these spot welds occupy about 3 to 15% of the consolidated material. The thermoplastic material may be a polyolefin, a polyamide, a polycarbonate, or a polyester, or mixtures of one or more of these fibres dependent upon the electrolytic cell for which use of the material is intended.
The separator material as a rule contains no additional bonding agents, 50 that the optimum porosity or labyrinth structure is obtained. This is desirable for a proper filtering action while at the same time retaining the rollability of the material and satisfactory separation of the positive and negative electrode regions within the storage battery.
The separator material comprises thermoplastic fibres and/or endless threads which are resistant to the electrolyte being used. For cells that -~
employ acid electrolytes, e.g., sulphuric acid, non-woven fabrics of polyester - fibres are particularly suitable. For alkaline storage batteries the use of polyamide or polyolefin fibres, particularly polypropylene fibres is re-commended. Polypropylene fibres are extremely alkali-resistant, and in storage -~
batteries so provided permit an elevated operating temperature. Hetero- ~
filamentous fibres of polypropylene and polyethylene base, if desired -mixed with separate polypropylene fibres have also proved to be ; effective. Polyamide heterofilamentous fibres, where applicable mixed with polyamide fibres also give good results.
The manufacture of the non-woven textile fabric is carried out in a known manner. The fibres may bé passed over a card or other suitable apparatus , . - . ':' : . '. : ' ' , , ~ : ; . .
,, . ~ , 1~3g349 .
1 in the form of a fleece, and this fleece is then consolidated by spot welding. Since the fibres are thermoplastic, the spot welding can be carried - out without difficulty and has the advantage that no bonding agents or aids such as emulsifiers, dispersing agents, catalysts or residual oligomers or fibre solvents need be present in the finished separator material. Such components would have a detrimental effect on the subsequent functioning of the storage battery and are therefore undesirable. Owing to the structure of the proposed separator material, the cause of any impairment in the function-ing of the separator can be quickly recognized and efficiently eliminated, particularly because the separator material is very uniform and is constructed without the use of any foreign substances. The cause of any fault in the storage battery, consequently, will generally not be found in the separator material.
The new separator material preferably comprises a labyrinth-like tangle of electrolyte-resistant thermoplastic fibres arranged substantially free and without bonding side-by-side and one over the other, only for consolidation are the fibres spot welded to each other. This structure results in a very high electrolyte capacity. In spite of the looseness of the structure, adequate mechanical stability, i.e., tensile strength, is obtained.
In many cases ribbing of tXe separator material is desired. This can be obtained by having the separator consist of an upper and lower non-woven sheet with preferably monofilamentous threads situated between them, these threads being retained and thus fixed at predetermined distances from each other between the spot welds. 8y reason of the retained threads, raised profiles of more or less marked character, depending on the denier of the retained threads, appear on the surface of the separator. These profiles serve prlmarily to avoid the so-called glass plate effect and to facilitate the conducting of the gases, sometimes generated during operation of the storage battery away, towards the top. Ribbing can also be effected mechanically, i.e.
by stamping.
: ~3~34~
1 The following examples illustrate specific embodiments of the invention.
Example 1 A fleece of fibres weighing 60 g/m2 was produced on a card from polypropylene fibres of denier 3.3 dtex, and 40 mm cut length. This fleece was then spot welded, the separate square weld spots having an edge length of 0.48 mm with a spacing of 48 welding spots per square cm. The welded area constituted about 11% of the total area of the separator. The tensile strength of the sample thus produced is 10 N/50 mm of strip width; the electrolyte absorption (30% KOH solution) is 360 g/m . A material of the same composition welded over its entire area on a hot calender shows an ~ 2 electrolyte absorption of only 120 g/m with a tensile strength of 30 N/50 mm strip width. The electric resistance of the spot welded material is also considerably less than that of the comparison sample welded over its entire area.
Example 2 - A fleece of fibres weighing 50 g/m2 was produced on a card from - -polyolefin fibres, the fibrous material consisting partly of polypropylene and partly of polyethylene denier 3.3 dtex/64 mm cut length. This fleece was spot welded, the individual square welding spots having an edge length - -of 0.30 mm, and there being 64 spots per square cm of separator area. The welding spots occupied about 6% of the total area of the separator. Tensile strength of the sample thus produced is 35 N/50 mm strip width; the electrolyte absorption (30% KOH solution) is 560 g/m . A corresponding --sample welded over its entire area absorbs only 130 g/m2.
Example 3 -A fleece of fibres weighing 100 g/m was produced on a card from 70 parts polyester fibres, denier 3.3 dtex/60 mm cut length and 30 parts unstretched polyester fibres (unstretched polyester fibres have a lower softenlng point than stretched and can therefore act as binding fibres).
This fleece was then spot welded, the individual square spots having an , 1~35~349 1 edge length of 0.48 mm and there being 48 such welding spots per square cm of separator area. The welded spots occupied about 11% of the total arèa of the separator. The tensile strength of the sample thus produced is 100 N/50 mm strip width; the electrolyte absorption (30% H2S04 solution) is 450 g/m .
A material of the same composition welded over its entire area on a hot calender had an electrolyte absorption of 130 g/m with a tensile strength of 150 N/50 mm strip width.
Example 4 Between two fibre fleeces consisting of 70 parts polyester fibres, denier 3.3 dtex/60 mm cut length and 30 parts unstretched polyester fibres with a weight of 50 g/m2, monofilament polyester threads with a thickness of 0.4 mm were laid at distances of 0.5 cm apart in such a way that on subsequent welding of the fleece each lay between two rows of welding spots.
Depending on the welding conditions (pressure/temperature) desired linear profiles are formed on the surface above the inserted threads, the profiles being elevated approximately 0.1 to 0.2 mm above the surface of the separator.
Example 5 A fleece of fibres weighing 70 g/m was produced on a card from 50 parts polyamide - 6.6 fibres of denier 1.7 dtex/40 mm cut length and 50 parts polyamide - 6 fibres. This fleece was then spot welded, the individual square welding spots having an edge length of 0.48 mm and there being 48 such welded spots per square cm of separator area. The welded spots occupied approximately 11% of the total area of the separator. The tensile strength of this material was adequate for the intended application;
its electrolyte absorption was considerably better than a separator welded over its entire area.
Storage batteries are known to comprise a multiplicity of alternate positive and negative electrodes immersed in a fluid electrolyte. In order to prevent contact between positive and negative electrodes, and hence an undesirable short circuit flow of current within the battery, the electrodes are insulated from one another by separators. The separators thus have the task of preventing the electrodes from coming into electrical conducting contact with one another, but without substantially hindering the passage of ions in the electrolyte.
A suitable separator material must therefore meet numerous require-ments. It must be stable in the presence of the electrolyte and resist oxidation, and it must have a definite weight per unit area, precise thickness and high tensile strength. It must be easily wetted by the electrolyte, which it must absorb quickly, and must have a high capillarity.
For this purpose large pore volume, or labyrinth structure is desirable with small, uniform pore diameters. The material must show low electrical resistance in the electrolyte, and must also be flexible and supple.
From the standpoint solely of function, a porous, non-conducting ceramic material suggests itself as a simple solution; however, such a separator at the very least does not have the necessary flexibility.
Good flexibility and rollability of the separator, material is necessary, especially for the manufacture of tubular storage batteries. In such instance both the positive and negative electrodes consist of thin plates which can be rolled. The separator material is therefore inserted between them, and it also must be capable of being rolled. After a strip comprising a positive and negative electrode and a separator has been rolled, the three-layer strip i~ inserted into a tubular housing filled with electrolyte, and the electrolyte is rapidly absorbed in sufficient quantity by the separator material and is retained in its pores. The separator material must therefore ~3g349 1 be stable in the presence of electrolyte flui~d being used and must be able to adhere closely to the positive and negative electrodes. It is also deslrable for the separator material to possess a labyrinth structure to provide a filtering action for solid particles separating from the electrodes.
More particularly in accordance with the invention there is provided, a separator material for electrolytic cells comprising, a non-woven textile fabric of electrolyte-resistant thermoplastic fibres and/or endless threads, -~
spot welds consolidating the textile fabric, the spot welds occupying about ~ to 40% of the total surface area of the consolidated material. Preferably, these spot welds occupy about 3 to 15% of the consolidated material. The thermoplastic material may be a polyolefin, a polyamide, a polycarbonate, or a polyester, or mixtures of one or more of these fibres dependent upon the electrolytic cell for which use of the material is intended.
The separator material as a rule contains no additional bonding agents, 50 that the optimum porosity or labyrinth structure is obtained. This is desirable for a proper filtering action while at the same time retaining the rollability of the material and satisfactory separation of the positive and negative electrode regions within the storage battery.
The separator material comprises thermoplastic fibres and/or endless threads which are resistant to the electrolyte being used. For cells that -~
employ acid electrolytes, e.g., sulphuric acid, non-woven fabrics of polyester - fibres are particularly suitable. For alkaline storage batteries the use of polyamide or polyolefin fibres, particularly polypropylene fibres is re-commended. Polypropylene fibres are extremely alkali-resistant, and in storage -~
batteries so provided permit an elevated operating temperature. Hetero- ~
filamentous fibres of polypropylene and polyethylene base, if desired -mixed with separate polypropylene fibres have also proved to be ; effective. Polyamide heterofilamentous fibres, where applicable mixed with polyamide fibres also give good results.
The manufacture of the non-woven textile fabric is carried out in a known manner. The fibres may bé passed over a card or other suitable apparatus , . - . ':' : . '. : ' ' , , ~ : ; . .
,, . ~ , 1~3g349 .
1 in the form of a fleece, and this fleece is then consolidated by spot welding. Since the fibres are thermoplastic, the spot welding can be carried - out without difficulty and has the advantage that no bonding agents or aids such as emulsifiers, dispersing agents, catalysts or residual oligomers or fibre solvents need be present in the finished separator material. Such components would have a detrimental effect on the subsequent functioning of the storage battery and are therefore undesirable. Owing to the structure of the proposed separator material, the cause of any impairment in the function-ing of the separator can be quickly recognized and efficiently eliminated, particularly because the separator material is very uniform and is constructed without the use of any foreign substances. The cause of any fault in the storage battery, consequently, will generally not be found in the separator material.
The new separator material preferably comprises a labyrinth-like tangle of electrolyte-resistant thermoplastic fibres arranged substantially free and without bonding side-by-side and one over the other, only for consolidation are the fibres spot welded to each other. This structure results in a very high electrolyte capacity. In spite of the looseness of the structure, adequate mechanical stability, i.e., tensile strength, is obtained.
In many cases ribbing of tXe separator material is desired. This can be obtained by having the separator consist of an upper and lower non-woven sheet with preferably monofilamentous threads situated between them, these threads being retained and thus fixed at predetermined distances from each other between the spot welds. 8y reason of the retained threads, raised profiles of more or less marked character, depending on the denier of the retained threads, appear on the surface of the separator. These profiles serve prlmarily to avoid the so-called glass plate effect and to facilitate the conducting of the gases, sometimes generated during operation of the storage battery away, towards the top. Ribbing can also be effected mechanically, i.e.
by stamping.
: ~3~34~
1 The following examples illustrate specific embodiments of the invention.
Example 1 A fleece of fibres weighing 60 g/m2 was produced on a card from polypropylene fibres of denier 3.3 dtex, and 40 mm cut length. This fleece was then spot welded, the separate square weld spots having an edge length of 0.48 mm with a spacing of 48 welding spots per square cm. The welded area constituted about 11% of the total area of the separator. The tensile strength of the sample thus produced is 10 N/50 mm of strip width; the electrolyte absorption (30% KOH solution) is 360 g/m . A material of the same composition welded over its entire area on a hot calender shows an ~ 2 electrolyte absorption of only 120 g/m with a tensile strength of 30 N/50 mm strip width. The electric resistance of the spot welded material is also considerably less than that of the comparison sample welded over its entire area.
Example 2 - A fleece of fibres weighing 50 g/m2 was produced on a card from - -polyolefin fibres, the fibrous material consisting partly of polypropylene and partly of polyethylene denier 3.3 dtex/64 mm cut length. This fleece was spot welded, the individual square welding spots having an edge length - -of 0.30 mm, and there being 64 spots per square cm of separator area. The welding spots occupied about 6% of the total area of the separator. Tensile strength of the sample thus produced is 35 N/50 mm strip width; the electrolyte absorption (30% KOH solution) is 560 g/m . A corresponding --sample welded over its entire area absorbs only 130 g/m2.
Example 3 -A fleece of fibres weighing 100 g/m was produced on a card from 70 parts polyester fibres, denier 3.3 dtex/60 mm cut length and 30 parts unstretched polyester fibres (unstretched polyester fibres have a lower softenlng point than stretched and can therefore act as binding fibres).
This fleece was then spot welded, the individual square spots having an , 1~35~349 1 edge length of 0.48 mm and there being 48 such welding spots per square cm of separator area. The welded spots occupied about 11% of the total arèa of the separator. The tensile strength of the sample thus produced is 100 N/50 mm strip width; the electrolyte absorption (30% H2S04 solution) is 450 g/m .
A material of the same composition welded over its entire area on a hot calender had an electrolyte absorption of 130 g/m with a tensile strength of 150 N/50 mm strip width.
Example 4 Between two fibre fleeces consisting of 70 parts polyester fibres, denier 3.3 dtex/60 mm cut length and 30 parts unstretched polyester fibres with a weight of 50 g/m2, monofilament polyester threads with a thickness of 0.4 mm were laid at distances of 0.5 cm apart in such a way that on subsequent welding of the fleece each lay between two rows of welding spots.
Depending on the welding conditions (pressure/temperature) desired linear profiles are formed on the surface above the inserted threads, the profiles being elevated approximately 0.1 to 0.2 mm above the surface of the separator.
Example 5 A fleece of fibres weighing 70 g/m was produced on a card from 50 parts polyamide - 6.6 fibres of denier 1.7 dtex/40 mm cut length and 50 parts polyamide - 6 fibres. This fleece was then spot welded, the individual square welding spots having an edge length of 0.48 mm and there being 48 such welded spots per square cm of separator area. The welded spots occupied approximately 11% of the total area of the separator. The tensile strength of this material was adequate for the intended application;
its electrolyte absorption was considerably better than a separator welded over its entire area.
Claims (12)
1. A separator material for electrolytic cells comprising a non-woven textile fabric of electrolyte-resistant, thermoplastic fibres and/or endless threads, spot welds consolidating the textile fabric, the spot welds occupying about 2 to 40% of the total area of the consolidated material.
2. A separator material as defined in claim 1, the spot welds occupying about 3 to 15% of the total surface area of the consolidated material.
3. A separator material as defined in claim 1, the thermoplastic being a polyolefin.
4. A separator material as defined in claim 3, the textile fabric consisting of fibres of polypropylene.
5. A separator material as defined in claim 4, the textile fabric including polyethylene fibres.
6. A separator material as defined in claim 3, the textile fabric consisting of polypropylene-polyethylene heterofilament.
7. A separator material as defined in claim 6, the textile fabric including polypropylene fibres.
8. A separator material as defined in claim 1, the thermoplastic being a polyamide.
9. A separator material as defined in claim 8, the textile fabric consisting of a mixture of polyamide fibres with different melting points.
10. A separator material as defined in claim 1, or 2, the thermoplastic being a polycarbonate.
11. A separator material as defined in claim 1, or 2, the thermoplastic being a polyester.
12. A separator material as defined in claims 1 or 2 comprising two layers of non-woven textile material arranged one over the other and joined linearly by spot welds in the longitudinal direction of the layers, and threads inserted in the intervening spaces between the layers and the spot welds for raising the profile of the surface of the consolidated material.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2438531A DE2438531C3 (en) | 1974-08-10 | 1974-08-10 | Separator material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1039349A true CA1039349A (en) | 1978-09-26 |
Family
ID=5922924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA231,219A Expired CA1039349A (en) | 1974-08-10 | 1975-07-10 | Spot-welded fibrous separator for battery |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS598952B2 (en) |
| CA (1) | CA1039349A (en) |
| CH (1) | CH596673A5 (en) |
| DE (1) | DE2438531C3 (en) |
| FR (1) | FR2281651A1 (en) |
| GB (1) | GB1513666A (en) |
| IL (1) | IL47631A (en) |
| IT (1) | IT1036979B (en) |
| NL (1) | NL7509458A (en) |
| SE (1) | SE424788B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NZ185412A (en) * | 1976-10-20 | 1980-03-05 | Chisso Corp | Heat-adhesive compsite fibres based on propylene |
| JPS54140941A (en) * | 1978-04-26 | 1979-11-01 | Mitsui Petrochemical Ind | Method of producing battery separator |
| US4216281A (en) * | 1978-08-21 | 1980-08-05 | W. R. Grace & Co. | Battery separator |
| US4220693A (en) * | 1978-08-23 | 1980-09-02 | P. R. Mallory & Co. Inc. | Composite separator/absorbent |
| FR2455366A1 (en) * | 1979-04-25 | 1980-11-21 | Europ Accumulateurs | LEAD SERVICE ELECTRICAL BATTERY WITH LIMITED MAINTENANCE |
| DE3116738C2 (en) * | 1981-04-28 | 1984-07-05 | Fa. Carl Freudenberg, 6940 Weinheim | Separator for electrochemical energy storage and process for its production |
| JPS59201367A (en) * | 1983-04-30 | 1984-11-14 | Japan Vilene Co Ltd | Separator for alkaline battery |
| GB2160701B (en) * | 1984-06-22 | 1988-02-24 | Chloride Group Plc | Separators for recombination electric storage cells |
| JPH04326725A (en) * | 1991-04-26 | 1992-11-16 | Tokyo Electron Ltd | Plasma apparatus |
| US5202178A (en) * | 1992-02-28 | 1993-04-13 | International Paper Company | High-strength nylon battery separator material and related method of manufacture |
| FR2751469A1 (en) * | 1996-07-18 | 1998-01-23 | Accumulateurs Fixes | SEPARATOR FOR NI-MH ACCUMULATOR |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH252424A (en) * | 1946-07-04 | 1947-12-31 | Otto Dr Saladin | Separator for galvanic elements and process for their manufacture. |
| GB1291987A (en) * | 1968-12-26 | 1972-10-04 | Exxon Research Engineering Co | Battery separators made from synthetic thermoplastic fibers |
| JPS4720244U (en) * | 1971-02-01 | 1972-11-07 |
-
1974
- 1974-08-10 DE DE2438531A patent/DE2438531C3/en not_active Expired
-
1975
- 1975-05-29 CH CH690175A patent/CH596673A5/xx not_active IP Right Cessation
- 1975-06-12 IT IT50035/75A patent/IT1036979B/en active
- 1975-07-03 IL IL47631A patent/IL47631A/en unknown
- 1975-07-10 CA CA231,219A patent/CA1039349A/en not_active Expired
- 1975-07-25 GB GB31103/75A patent/GB1513666A/en not_active Expired
- 1975-07-28 JP JP50091838A patent/JPS598952B2/en not_active Expired
- 1975-08-07 SE SE7508914A patent/SE424788B/en not_active IP Right Cessation
- 1975-08-07 FR FR7524705A patent/FR2281651A1/en active Granted
- 1975-08-07 NL NL7509458A patent/NL7509458A/en active Search and Examination
Also Published As
| Publication number | Publication date |
|---|---|
| FR2281651A1 (en) | 1976-03-05 |
| SE7508914L (en) | 1976-02-11 |
| DE2438531B2 (en) | 1981-04-09 |
| FR2281651B1 (en) | 1981-02-06 |
| JPS598952B2 (en) | 1984-02-28 |
| SE424788B (en) | 1982-08-09 |
| IL47631A (en) | 1979-07-25 |
| CH596673A5 (en) | 1978-03-15 |
| DE2438531C3 (en) | 1982-04-08 |
| IT1036979B (en) | 1979-10-30 |
| JPS5138036A (en) | 1976-03-30 |
| IL47631A0 (en) | 1975-10-15 |
| GB1513666A (en) | 1978-06-07 |
| NL7509458A (en) | 1976-02-12 |
| DE2438531A1 (en) | 1976-02-26 |
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