DE1935973A1 - Solid electrolyte fuel cell battery - Google Patents

Description

PATENT, & LAWYER

DIPL-ING.H. VON SCHÜMANN 1935 173

8 Munich 22, Widenmayerstraße 5

Telegram address: Protector Munich

Phone: 224893

Bayer. Mortgage and Exchange Bank Munich, Tfu7 »1969

Account no.Mx 63 42 2 / ϊ ¹

Postal checking account: Munich 49463 ■ '

COMPAGNIE I ¹ EAFOAISB "DB RAPi ¹ INAGE, Paris, France

Solid electrolyte fuel cell battery

The invention relates to a battery made of fuel elements with solid electrolytes, which operates at high temperatures.

As is known, fuel elements are the subject of more numerous Research aimed at improving their technology, for so far it has not yet been successful, one that works under normal conditions and with common reagents Create fuel element, although the theory of fuel elements has long been known. The fact, however, that with electrochemical combustion taking place in a fuel element takes place, no such drop in performance is associated is, as it is with the thermal engines due to the Carnot principle is given, prompts the industry to seek solutions to the technological problems of fuel elements.

The works dealing with fuel elements, are oriented in different directions, with aqueous electrolytes that are effective at low temperatures in the The focus will soon be effective at higher temperatures Electrolytes from molten salts or at high temperatures effective solid electrolytes are discussed.

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The latter type is known to have significant advantages over the other species studied . In addition , the solid structure enables easy handling, furthermore hydrocarbons can be burned because of the high working temperature, and no corrosive liquids are present. ..... ■. ■■

However, the solid electrolytes used in fuel elements are used, have high resistances and cause a loss of power due to the ohmic voltage drop inside the electrolyte itself. For example lies the resistance of an electrolyte atis stabilized. Zir-

konoxyd at 800 ⁰ C in the order of several sehn ohms

per cm. The investigations aimed at this type of fuel element have had the aim of reducing the thickness of the electrolyte in order to reduce the inner Y / iderstahd of the fuel element. The reduction in strength of the electrolyte has, however, a mechanical fragility of the whole consisting of electrodes and electrolytes - a consequence, which has led to the fact that this solution has been practically abandoned in favor of thicker electrolytes, which are mechanically more resistant, but work at very high temperatures to compensate -and at temperatures above 1000 ⁰ O to the power loss due to the resistive voltage drop. These very high temperatures must, however, be avoided if one wants to have a maximum amount of free energy available, and if solid silver is to be used as the electrode, which, as is known, melts at 961 G.

In US patent Ur. 3.192 070 describes a fuel element with solid electrolytes which worked at over 1000 ^° C. In the embodiments specified in the patent, the electrolyte has a considerable strength, be it to accommodate the electrode made of molten SiI-

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About when, a fuel element takes the shape of a crucible has, be it to ensure the required mechanical strength of the whole, if the fuel element is in the form of a tube "which has three concentric layers which contain the first electrode, the electrolyte and; Here represent the second electrode (made of molten silver). To the Thickness of the electrolyte causing the loss of power ', there is also the difficulty of adding two elements in, Switch series ζΐΐ. If you can increase the amount of current generated by an element by increasing the surface of the electrodes, for example by lengthening the tube of "three concentric layers," then you can in contrast, do not increase the tension obtained by that you connect two neighboring elements compactly in series »

The object of the invention is to remedy the above disadvantages. In particular, the invention provides a battery consisting of fuel elements, the solid electrolyte of which can have a very small thickness, so that it causes only small ohm see he losses. In this context and in this description, the term “fuel ^{element 11”} is to be understood as an isolated fuel element, ie an element consisting of an anode, an electrolyte and a cathode, while “battery” is to be understood as the combination of several fuel elements connected in series The invention also provides a battery of fuel elements which operate at a temperature below the melting temperature of silver. Finally, it is also an object of the invention to provide a battery of fuel elements with solid electrolytes, which are connected in series in a compact manner. - ■ / '"' .. '"-'

- .. ■ The battery according to the invention made of fuel elements with solid electrolytes and high working temperature is characterized by -several each off. a first electron Iei-.

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tend electrode, a second electron with opposite sign conductive electrode and a contacting solid electrolyte arranged between these electrodes consisting of elements stabilized in conical phase zirconium oxide, whereby the first electrodes of the elements are electrically isolated from one another and are part of a partition _t which the mechanical Stability of the battery is guaranteed and the housing of the battery is divided into two rooms, in which the gaseous fuel or an oxidizing grass flow, and furthermore the electrolyte of each element as a thin layer on the partition wall and in contact with the first electrode of the element is arranged so that the separating wall and the electrolyte layers of all elements form a gas-tight unit «, and ... finally, an electron-conducting material is arranged between the electrolytes of the elements and each of the first electrodes with the second electrode of the adjacent element v binds, and the generated current is dissipated by electron conductors, which with one electrode of the first battery element or with the electrode opposite. ■■ "" ,. The sign of the last battery element are connected.

. . . "Further advantageous embodiments of the invention are in the attached subclaims and the following examples Description of some embodiments of the invention listed on the basis of the attached drawings. In ^ these shows: " ·

Pig. 1 shows the view of the longitudinal section through a first embodiment of the fuel element battery according to the invention

Fig. 2 is a view of the section along the line II-II in Fig. 1j; ,;

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Pig. 3 is a side view of a partially cutaway Another embodiment of the battery according to the invention j

Mg. 4 the view of the section along the line IV-IV

in ed. 3 $ ■.

Mgο 5 the view of the longitudinal section through a third embodiment the battery according to the invention, and

Mg. 6 the side view of a partially cut-open fourth embodiment of the fuel cell battery according to the invention.

The battery according to Mg. 1 and 2 has a housing 1, which is divided into two lines 1a and Tb, namely ■ by a partition 2. This consists of sections 3 inert, non-conductive and gas-impermeable material and the anodes 4 of the downstream fuel elements of the Battery together, with the sections 3 and the anodes 4 in an alternating arrangement. In the present jail are the anodes 4 made of porous, ferritic steel. The pores, shown schematically by channels 5, make it possible the gaseous fuel, to the anode / electrolyte boundary area to get. The electrolytes 6 of the three elements of the battery consist of gas-impermeable, stabilized zirconium oxide and are arranged on the anodes 4. The electrolyte 6 of each fuel element protrudes a little over the immediately adjacent section 3 made of inert, non-conductive and gas-impermeable Material and so separates from the. Anode '4. of the .related Element from a conductor 7, which the anode 4 of the adjacent element with the silver cathode 8 of the considered Element electrically connects. The lines 1a and 1b are therefore tightly separated from one another, since the sections 3 are made of inert Material are gas-tight, as is the electrolyte 6 itself,

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which covers the porous portions of the partition 2 which form the anodes. In addition, FIGS. 1 and 2 show the fact that is important for the invention that the electrolyte only needs to be present in a very thin layer, and consequently can only have a very low ohmic resistance, because the mechanical resistance of the battery through the partition 2 is ensured, which can be given such a strength that the required mechanical properties are guaranteed without affecting the energy performance of the battery. FIGS. 1 and 2 also show the simplicity of the series connection of the fuel elements made to form the battery. The electrical connection between the anode of one element and the cathode of the following element is ensured by a layer of any conductive material, which can be, for example, a material of the cathode type or any other electronically conductive material. The current generated by this battery, which consists of three elements, can be collected or discharged by means of electrical lines 9.

The series connection of the fuel elements can be modified. For example, it is not necessary that the electrolyte layer 6 of each fuel element overlaps the section 3 of inert material which the anode 4 this element separates from the anode 4 of the previous element, rather it is sufficient if the conductor 7, which is the anode 4 of one element with the cathode 8 of the following element connects, with the anode 4 of this acted folgentien Element is not in contact. This can be, for example be realized in that between the conductor 7 and the anode 4 of the following element is a layer of an insulating Material is arranged. : ·

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Materials other than those specified may be used for the various parts of the battery described above will. In particular, the conversion can be reversed if the electrodes 4 / and 8 are made of other conductive materials than ferritic .. steel and silver. In this * ■■■■ "- ■ -. ■■," ■■■. - ■■■. ..-. ■. Pail The oxidizing gas of the cathode became through the line Ib and the gaseous fuel of the anode through the line la fed. ■,

. Fig. 3 shows a tubular design of the battery according to the invention, wherein the same parts have been given the same reference numerals as in _r Figs. The partition 2 divides the housing'1 of the battery into two coaxial lines ta and 1b, namely the line 1b enclosed by the tubular partition 2 and the outer, annular line la between the housing 1 and the partition .2. As with the *. Battery after the pig. 1 and 2, the gas-tight seal between the lines Ta and Tb is brought about by the inert and non-conductive material on the one hand and the electrolyte on the other hand, which covers the anode made of ferritic, porous steel. The conductors 7 connecting the anode of one element to the cathode of the following element form bings on the tubular partition 2. The tubular shape of the battery according to the invention enables a considerable increase in the surface area of the solid electrolyte in relation to the volume of the battery and consequently noticeably increases the specific power of this battery.

\. The battery according to the invention can be used on different Way to be made. The partition 2 can be manufactured, for example, by the porous electrodes and the inert, non-conductive and gas-impermeable material put together whereupon the electrolyte is applied to this material in that it, initially as a powder

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is applied, which is then sintered at high temperatures until a gas-impermeable electrolyte layer results. The sintering temperatures can be higher than the melting temperatures certain "metals, '" which can be used as electrodes are so that the metals used are applied to the The type of electrolyte application must be coordinated «The electrodes 8 of Mg. 1, 2 and 3 can in particular be painted on, as can the conductors 7. The current supply and discharge lines 9 ν can for example consist of wires which ail the corresponding electrodes are welded to the ends of the battery are. - - = ■ .- ■:

Y / enn in the manufacture of the. Battery used Electrolytes are sintered at very high temperatures, which must be higher than the melting temperatures of the ones- ' Metallic materials which are used as electrodes in the partition 2 can then be proceeded in the manner described below, the electrode in question no longer being made of a porous conductive material consists, but of a metallic layer that is inside the forums of a non-conductive, but porous and as a support; serving refractory material is deposited.

Such an embodiment is shown in FIG. The housing 11 of a battery consisting of three fuel elements is divided by a partition 12 into two lines 11a and 11b, the partition 12 being made electronically conductive sections 13 and sections H made of refractory Material, and the sections 13, 1'4 are arranged alternately - in the case of the refractory porous material it can be, for example, stabilized zirconium oxide. In the pores of this material there is a metallic layer 15 deposited, which is the anode of the fuel elements of the battery forms. Preferably the mean pore diameter is

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of the refractory material of the sections 14 is not much greater than the thickness of the electrolyte layer 16 so that the material of the sections 14 on either side of the partition wall 12 can withstand the pressure changes of the gases to which the battery is subjected. The anode 15 stands with the electrolyte layer 16 in contact, which covers the porous refractory material and ensures the gas-tight seal of the lines 11a and 11b from one another * The electrical series connection of the elements of the battery is ensured by the electronic conductor 17. The anode of an element is in electrical connection with the conductive section 13, which separates two adjacent fuel elements, and the conductor 17 connects this conductive section 13 to the cathode 18 of the subsequent fuel element. Lines 19 serve to divert the current generated by the battery when an oxidizing gas is supplied to it through line 11a is, while a gaseous fuel off flows through the line 1, 1b, the temperature of the housing 11 being about 8QO ⁰ G ..;

In the Pig. 5, the electrolytes 16 can be sintered at very high temperatures without " the refractory material of the sections 14 would be destroyed, on which then the conductor forming the anodes 15 is deposited.

In Fig. 6 is a tubular embodiment of a battery according to the invention; with three fuel elements in Pig. 5 reproduced type shown. Same parts; the execution forms according to Pig. 5 and 6 are provided with the same reference numerals. The advantages of the embodiment according to FIG. 6 over that according to Pig. 5 · are the same as the embodiment of · Pig. 3 compared to that according to Pig * 1 and 2. In particular, the greater specific power of the battery according to Pig -, .- β, compared to that according to Pig. 5 to be highlighted. '. "■ -

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Also, materials other than those mentioned in connection with the illustration of FIGS. 5 and 6 can be used with success. As the refractory, porous material, ceramic materials other than those which form the electrolyte, in particular zirconium, can be used. oxide with different contents of stabilizing oxides

If the composition of the refractory material is the Sections 14 are similar to that of the electrolyte, then This avoids mechanical tension, which increases with increasing Temperature due to the different coefficients of thermal expansion otherwise would arise.

The batteries described above operate at -atmospheric pressure and equally good at higher pressures. Working at elevated pressures increases the speed of the reaction between the gases and thus the performance of the battery is increased «

Both with äen batteries according to FIGS. 1 to 4- and those according to Flg. 5 and 6, the thickness of the electrolyte layer can be reduced to the maximum achievable in a known manner, and thus the internal electrical resistance of the battery can also be reduced, due to the carrier which forms the partition from which the Anodes are a part, which ensures the mechanical rigidity of the device. In addition, the fuel elements of the battery can be simply connected in series by means of a conductor that is painted or applied in some other way, such as the electrode itself. '

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Claims (4)

Expectations Battery made of fuel elements with solid electrolytes and high working temperature, marked by several -well from a first electron .conducting electrode (4; 15), - one second. Conducting electrons with opposite signs. Electrode (8-1.8) and one between these electrodes arranged solid electrolytes (6; 16) in contact with them and consisting of elements consisting of zinc oxide stabilized in the cubic "phase, the first electrodes (45 15) of the elements being elec- tric. triseh isolated from each other and part of a partition wall- (2j 12) are that guarantee the mechanical strength of the battery and the housing (1j 10) of the battery in two spaces (1a; Ti ä and Ib1 11b) divides into which the gaseous fuel or an "oxidizing Sas flow, and furthermore the Elektro'-lyt each element as a thin layer (6 $ 16) on the partition (2; 12) -and- in contact with the first electrode (4 j 15) of the element is arranged so that the partition (2; 12) and the Electrolyte layers (6 | 16) of all elements form a gas-tight unit * and finally an electron-conducting unit Material "(7; 17) is arranged between the electrolytes (6-16) of the elements and each of the first electrodes (4 | 15) with the second electrode (8 | 18) of the neighboring element "'binds" the generated current through electron conductors (9? 19) is discharged, which with an electrode (8j 18) of the first Battery element or with the electrode (4; 15) opposite The sign of the last battery element are connected « 2. Battery according to claim T, characterized in that the Partition wall (2) from alternating sections (3) refractory, inert, gas impermeable material and the first Electrodes (4) consists of which electrodes (4, 4) from one 009811/0951
BATHROOM porous, electron-conductive material and from the Electrolyte layers (6) are covered in such a way that the separating, wall (2) in connection with the Electrqlytschichten (6) gas-tight is, wherein an electron conductor (7) connects the first electrode (4) of each element with the electrode (8) opposite sign of the adjoining element, while the first electrodes (4) of two adjacent elements from each other electrically insulated and the second electrodes (8) on the electrolyte layers (6) are arranged. 3 · Battery according to claim 1, characterized in that the Partition (12) consists of alternating sections (13; 14) made of conductive, gas-impermeable or fireproof, porous material, with porous, Refractory material, the electrolyte layers (16) arranged are, so that the partition wall (12) in connection with the electrolyte layers (16) is gas-tight, and furthermore the first Electrodes from one inside the pores of the refractory ma- '~ terials deposited and with the associated electrolyte layer (16) layer in contact (15) which conducts electrons Material are formed, while the second electrodes (18) are each arranged on an electrolyte layer (16), and finally the elements are connected in series by electron conductors (17) which every second electrode (18) with the adjoining section (13) made of electron-conducting material of the partition (12) connects, which section (13) connects to the first electrode (15) of the adjacent element contact has, v / äirend the current generated by the battery through electronic conductors (19). is discharged, which with an electrode (18) of the first element or the electrode (15) opposite. The sign of the last element are connected. 4. Battery according to claim 2 or 3, characterized in that » that the partition (2; 12) is tubular and a ■ 0098 11/0 Grass line (1b; 11b) includes, while the other gas line (la-i-11a) from the battery housing (1; 10) and the to it coaxial partition (2; 12) is limited. Ö098 I I / 0951