DE2334052A1 - RECHARGEABLE ELECTROCHEMICAL ELEMENT AND METHOD OF ITS MANUFACTURING - Google Patents

Description

COMPAGHIE GENERALE D'ELEÖTRICITE, Paris, France

Rechargeable electrochemical element and process for its manufacture

Addition see patent (patent application P 22 09 086.4)

The invention relates to a leather-chargeable electrochemistry ohea element and also has a process su its manufacture sum object ·

In the main patent ··. ··. (Patent application P 22 09 086 * 4) is a reverence for the manufacture of a rechargeable electrochemical element described in the charged State next to one another has thin solid layers in the following order

one formed from an electron conductive material cathodic collector;

a catholyte that provides anions with lithium form a SaIs;

309884/1136

• "inside" in Mthium eels and a substance of old solid structure containing separator «which forms an insulating ion conductor for the electrons and for the latholyte is impermeable;

- and a lithium anode.

The procedure according to the main patent is compensated by the fact that the separator is obtained by dissolving the lithium salt in a solvent and that a thin, solid sole is then formed from this solution and the substance with solid (Jefle _{) in} such a way that the litaiuas as sumlndest partially solvated int «

Can be iia other was there f &# sg g © "fe" n _t DAJ a binder susaamen used with the LSsungismitttl ·

* Different binders were verges were incumbent, and in particular t r the case "where the solvent consists of water: polyvinyl alcohol; and in that? all _f where the solvent from Metb9.ro! or ethanol consists of acetate or polyvinyl butyral. It was found in the context of the present invention that a binder formed from polyvinylforsal is particularly advantageous when the solvent is formed from propylene carbonate.

The invention is thus based on a Terfshren sur Production of an electrochemistry just 3E3mientes accordingly the main patent that elß # Ansf & X solid Sttnnsv layers in the following order in the launches ^ state!

- a cathode-equal £ ollektoi% of the tinm electrons conductive material formed let;

309834/1136 - 5 -

- «in a catholyte, which Antonen delivers who are capable are, with which lithium form a sale iu,

- one an Llthiumeal and one material old solid structure containing separator, which forms an ion conductor that has an insulating effect on the electrons and is impermeable to the xatholyte,

- a lithium anode.

The process is carried out in such a way that the separator

obtained in the following stages vlrds

- the Idthiumeal and an organic binder in a top of a solvent, which consists of propylene carbonate CH ₅ -OH-CH ₂ -0-00-0;

- one impregnates a solid porous base of the old one solution;

- this impregnated Sohioht is dried sufficiently gently, then at least partially through which this solvent remains isolated, whereby the material τοη solid Oef structure duroh this porous Sohioht and this binding agent is formed, the process comprising the fact that polyvinyl foxmal is used as the binding agent is used.

The invention will now be based on the single Plgur in more detail be explained, which represents a section duroh an electrochemical ohee Esftent according to the invention.

From this vigor one recognizes an element which is in

3098ΘΑ / 1 136 - 4 -

• contained in housing let. This consists of an insulating side wall Z _9, for example made of plastic material (plastic) and a cover 4 and a base plate 6, both of which are made of steel.

A catholyte 8 »rests on the plate 6 above Separator 10 is provided, which in turn is of a consisting of a lithium plate anode 12 is superimposed. These latter three elements will be against each other and against the base plate 6 by a Yertellerplatte 1? made of pressed stainless steel, which is itself pressed onto this anode 12 by means of a spring 14 made of steel. This pen will swisohen the plate 13 and dam Deokel 4 compressed and ensures the electrical contact between the anode 12 and the cover 4. The deodorant 4 and the base plate 6 Tom electrical standpoint form the terminals of the electrochemical element. Ss be however pointed out that the spring 14 and the distributor plate 13 can be absent if the various layers or if the wall 2 has sufficient elasticity exhibit.

In the case of a single element, the electrochemical reaction is transferred through the transformation of copper-XI-sulfide CuS into copper-I-sulfide Cu ₂ S at the cathode and the formation of lithium sulfide at the anode.

In the following we shall look more closely at the method of manufacture and the composition of the layers just described

309884/1136

To be received.

The catholyte θ is formed in the following stages

- to set DME mixture at a temperature forth dl · preferably "wipe 50 and 90 and in particular ⁰ O ⁰ O wipe 60 and 70 lieft, the proportions Gewiohtstelle Sindt

. Copper (II) sulfide powder CuSs 70 to 80 *. Solvent 27 to 18 #
. Binder 3 to 2 f

The copper sulfide OUS is in the form of a fine semiconducting one Pulrere ror. Its specialty is its electrical power tr specific resistance, the sound is * · * Älektronenart ,,

▼ orsugsweis · substantially below a »hundredth of an oheientiaeter. Sr can, for example, sit Help · of a copper and Sohwefelge "are obtained iseheβ, which can react such IiUIt ₉ DAB Iupfer-1-sulfide formed Ou 8» sulfur is dea obtained powder * ansohlieiend to this reaction sugesetsts a new reaction is caused, in such a way that lupfer II sulfide is formed. The powder obtained with the help of this Bveiten reaction is washed with isopropylamine, which eliminates any remaining sulfur dioxide. The result is a lupfer- • ulfldpulrer that has the required bigenso properties. However, this powder can be obtained in different ways, for example by a method on. naflea path which takes the following steps

309884/1136

Sodium sulphide crystals are dissolved for saturation in boiling water,

sulfur is then added until saturation is scarce.

A special solution of copper sulphate is used separately Ou SO4 made in water «

one then mixes the two solutions and one obtains Susceptible product of CuS and several percent Sulfur,

that in ObersohuB forehand eat sulfate Uu SO ^ is through Washing in water eliminated. The sulfur excess is sohlieBlioh by washing, carbon disulfide is eliminated

The solvent UAndeit ec is propylene carbonate CH, -CH-CH «-0-CO-O»

The binding agent is polyrinyl formal * Ss is about one by condensation of polyvinyl alcohol with loraaldehyde löilioati binders. The molecular weight of the PolyTinyl alcohol is located in Tersugswelse awisohen 24 000 and 40 000. The condensation reaction, in which it eioh. around an aietalization is carried out in such a way that that is, for example, £ 82 of the alcohol groups in polyvinyl alcohols aietallelert are, however, Xs can be more advantageous be to increase this proportion su

The demisoh from Kupfersulfii, the solvent and the Torher mentioned binder is meoaanlüdh. stirred or mixed, fierart, dal a vi.> * -, uee eohwarie

309884/1136

• 7 -

233A052

- 7 very homogeneous slurry is formed.

If necessary, this soling is left at ambient temperature cool down to obtain a more or less plastic uel su.

The viscous slurry is poured or spread the previously obtained gel thickly on a metal workpiece, which is the role of the cathodic collector should play. In the case of the figure, this metallic workpiece can be the base plate 6 made of soft steel. she

however, it can just as easily be formed from a copper grid be, which is placed on a thin copper foil in the event that several electrochemical elements in series are to be switched in one and the same box or housing.

The separator 10 is made by making a mixture with the following parts by weight:

. Solvent about 88 %
. Binder: 4 to 6 tons
• Lithium sais around $ 6 to $ 8>

The solvent is made from the aforementioned propylene carbonate educated. The binder is the aforementioned polyvinyl formal. The lithlumsals can In particular from lithium iodide or preferably lithium perchlorate LlClO * be formed.

These components of the separator are in the following way brought together ζ

- One dissolves the binder in the solvent at a

309884/1136

Temperature preferably between 50 and 90 ⁰ C, in particular between 60 and 70 ⁰ C;

- One lb * et the lithium al β at the same temperature in the solution previously obtained;

- One impregnates one with the obtained liquid porous support. This porous carrier can, for example, be an asbestos paper in the bead for example, "wipe 12 and 40 hundreds". millimeter act or if you want a smaller bead a cellulose paper of the filter paper type, whose Sioke Bvisohen 5 and 12 hundreds *! Millimeters can.

It goes without saying that this filter paper should be of a type that does not include any of its elements in Propylene carbonate is soluble.

The support so impregnated is left for a few days at ambient temperature under a stream of dry nitrogen stand in such a way that a first partial desolvation the thus obtained shoe is produced.

- A partial Staer & ce Sesolvatlon is preferably a drying at a temperature between 80 ° and 100 ⁰ C for a period "wipe one and six minutes, preferably, nor adjacent three minutes a dry Stiokstoffatmosphäre performed such that each insertion is avoided by water.

The layers obtained in this way are preferably brought together in a dried fabric atmosphere,

3 09084/1136

such that the introduction of water is avoided. First of all, a stack of these layers is produced if only a cathodic collector such as the bottom plate 6, a catholyte such as 8, a separator such as 10 and a lithium anode such as 12 is provided, be it that a stack of several AaI follows one another of four soles of this type is provided, in which case the cathode-solitary double-solenoid collectors are not formed by a base plate such as 6 but by a copper grid which is placed on a thin copper foil. Before the encapsulation, ie the closing of the nozzle, the wall 2 and the plates 6u. 4, a Yorkompressin is provided, the pressure being on the order of 50 to 200 g "per cm, such that an intimate contact is established between the layers in contact warm state take place, ie at a temperature Bwlsohen 50 and 90 ⁰ C, preferably between 60 and 70 ⁰ C.

In the latter case it is not necessary to use a teder like 14 and auoh do not use a distributor plate like 13 au, for intimate contact with the superimposed layers maintain.

For example, an electrochemical generator according to the invention which is able to generate one hundred milliamps / Hour at two volts su supply and an average output of the order of magnitude of 20 milliwatts and power plates. of 300 microwatts, have a surface or top layer of 3 cm, the thickness of the lithium anode 12 at 0.2 mm, wipe the thickness of the separator 10 ″

3098Ö4 / 1136

0.1 and 0.5 mm and the catholyte thickness at 0.8 lies.

In the event that a voltage of 10 volts is desired for the same power and the same available energies and the surface area is noon at 3 am , 5 successive layers of the same can be stacked in series in the middle of the same housing. In each of these successions of layers, the I> ithiu & aneäe 12 can have a block of 0.1 mc, the separator 10 a thickness of between 0.1 and 0.5 and the satftolyt 8 a block of 0.2 nm. B :; It seems that the available Yolaena energy is lower in the case at issue than in the first J3-11 1st »Especially due to the Sata & ea ** £« £ the blocks of the separator regardless of the amount of risk that is to be delivered.

The invention was made in view of a tight cash position only on the basis of one embodiment refines “Changes and amendments are within the framework the invention.

Claimsι • 11 -

3Q9884 / 1136

Claims (13)

aisprOohb 1. Process βατ production of an electrooheaiechen Elementes, Aas la charged state a number of thin solid layers in the following order - one made of an electron-conductive material cathodic collector, - a catholyte capable of producing anions, which form a SaIa old lithium su In'der Lage are, can deliver, - a a Uthluasals and a substance containing old festea Oefttge separator "which forms a Ionenlelter ₉ of the insulating virkt for electrons and 1st for the latholyten impermeable; - A lithium anode, with the separator In the following Levels is obtained χ the lithium metal and an organic binder are dissolved in an excess of a solvent consisting of propylene carbonate OHv-CH-OE ₂ -O-CO-O; a solid porous layer is impregnated with the one obtained Solution; - this impregnated layer is sufficiently gentle dried so that the Llthluasals at least partially remains solatized by this solvent, whereby the material old festea (tofttge duroh these porous Sohioht and this binder is formed, according to patent. .. (patent application P 22 09 086.4), since 309884/1136 - 12 - characterized in that all binders are polyvinyl formal is used. 2. The method according to claim I ₉ characterized in that the xatholyte is obtained by mixing copper (II) sulfide CuS and a binding agent consisting of polyrinyl formal with propylene carbonate. 3. The method according to claim 1, characterized in that that the lithium eel consists of Mthiumperohlorat. 4. The method according to claim 1, characterized in that the polyvinyl formal has a molecular weight between 20,000 and 40,000, a proportion of more than 70 i> of the alcohol groups of the corresponding polyvinyl alcohols being metalized by means of formaldehyde. 5. The method according to claim 1, characterized in that that the separator according to the following stages or Process steps is obtained, the proportions being by weight «parts: A mixture of 4-6 parts of binder with 85% dents solvent is produced at a temperature of 60 to 70 ^° C .; - Dissolve in the solution thus obtained at the same temperature 6 to 8 parts of this lithluasalses; - aan impregnates a porous! carrier with the so obtained Solution; - the porous carrier impregnated in this way is preserved for a day or more at ambient temperature and in the 309884/1136 - 13 - ORIGINAL INSPECTED - 15 degrees of moisture; - and the porous one is left so impregnated and preserved Carrier at a temperature between 80 and 90 ⁰ O in the absence of moisture for a period between 1 and Dry for 6 minutes. 6, method according to claim I _9, characterized in that the catholyte is produced according to the following process stages or steps: - at a temperature "wipe 50 and 90 ⁰ C, the following elements in the following Gewichtβte11en be gealtohti . Copper sulphide as a fine powder with a specific resistance of less than a hundredth of an ohmic centimeter, in a proportion of 70 to BQJi; . this solvent in a proportion of 27 to 18%; . this binder with a proportion of 3 to 2 1 »t - Stirring or mixing then takes place the temperature of the mixture thus obtained to produce a thick black homogeneous suspension; - the Qemlsoh obtained is allowed to cool; - the plastic QeI obtained in this way is applied to it Cathode collector on " • U 309884/1136 7. The method according to claim 1, characterized gekenneeichnet, da * ditet Sohiohten in intimate contact with each other by a DTI Vorkoapression Druok a "wipe 50 and 200 g / cm at a temperature" wipe 50 and 9O ⁰ O are brought. 8. The method according to claim 1, characterized in that dad through these layers in intimate contact with financiers Pre-compression with a brisk wipe 50 to 200 g / cm be brought at ambient temperature, with a distributor plate (15) eyeed on this I & thiua anode (12) and then a spring (14} ^ & i * ssYe2? divider plate (13) like this is applied, there is a permanent bridge on this plate is maintained. 9. Rechargeable electrochemical element that in the charged state it consists of thin solid layers in the following order! - a cathodic collection made of slntm electron-conducting material! ¹ ; - a catholyte, the Aüic-nen, the old LitMia form a SaIi, liefest ι - sinen Separator Kit ®in @ r surmounts € ii porous layer, dl · by a mixture of * t & m orfanlsokeii Biiid ^ eittele old a lithium Sale imprlg ^ is ^ t is _$ tapping the one of propylene carbonate CH ^^ CH ^^ H ^ ^ C ^ vC-O ftl ^ formed solvent solvated i st1 "l9 £ ^ ih ~" aa * l is formed »wiser ir. B $ suf with ils has an insulating effect vm £ x ^ dvschlXisie for the * I-st ^ ölytea 15 - - a Llthium & node, known by the fact that dleeee organ! βehe binder consists of polyvinyl formal. 10. Electrochemical element according to claim 9, characterized in that this lithium salt is lithium perchlorate 1st. 11. Electrochemical element according to claim 9, characterized in that this catholyte (8) consists of a Gem isoh au * copper-II-sulfld of a specific electrical resistance less than a hundredth of an ohm per meter with the binder and the solvent "consists. 12. Electrochemical element according to claim 11, characterized in that in this catholyte (Θ) the proportion of copper sulfide is between 70 and 80 percent by weight that of the solvent "between 27 and 18 " and that of the binder between 3 and 2 * amounts to. 13. Electrochemical element according to claim 9 t daduroh ekenneelehnet that in this separator (10) the weight of the llthlumalses between the ^ fold and twice the detergent weight. 309884/1136 Blank page