DE2810320A1 - CATHODE FOR A CELL, METHOD FOR PRODUCING SUCH A CATHODE AND RECHARGEABLE BATTERY CONTAINING IT - Google Patents

Description

B e schrelbun κ

The invention relates to a cathode for a cell, a method for making such a cathode, one such ! Cathode containing cell as well as the Itaraobilization of "certain electrochemical reactances.

There is an ever increasing need for suitable ones
Energy storage mechanisms im. general and after an over _a cnui> Eriergiespeicherimg in Enargieverteilungenatzen and after an electric vehicle antx'ieb your special.

Recently, the development of improved electrochemical energy storage mechanisms is increasing
Attention paid. The most promising developments relate to cell systems in which alkali metals are coupled with strongly electronegative elements, such as sulfur
are «, but these developments have so far been delayed
the difficulties encountered in controlling and handling the reactive electrochemical reactants or.

There are two G-runa procedures, according to which at dar Unbex'succuing; This is done with alkaline total Schviefel cells. In the first basic procedure the suggestion was that the electrodes should consist of molten sodium and sulfur, separated by a solid electrolyte. The solid slek «trcj- ^ b .'3ο 11t5 Λβ'Χ üopviius: a Zwaalt Cleria ^ :, s ~ ls ^ Lc ^ crolyt ^ u act as well as Äeti necessary sepsjcator for di'5 closed electrodes represent« So vn.u- ds baispiölsv
β- alutainium dioxide proposed as a solid electrolyte "

ORIGINAL

β-Alumina is a ceramic material that serves as a separator for the molten electrodes and has good ion conductivity for sodium ions at around 300 ° C. Molten sodium and molten sulfur are dangerous and, particularly at operating temperatures at that time, they must be effectively kept separate from one another. The β- aluminum oxide ceramic electrolyte is shock-sensitive. In addition, it tends to corrode through metallic liatx'itini, which leads to the formation of cracks and defects and thus limits the service life of such a cell.

In the second basic method, it was suggested to minimize the electrolyte by using an electrolyte consisting of molten ionic salts which are electrochemically compatible with the electrodes. If such electrolytes are used, the operating flow rate of the cell must be above the melting point of the electrolyte. An example of such an electrolyte is the LiJ / KJ eutectic, d-13 bsi for example. 255 ° C steel rail. Xierden is currently developing other ionic salt systems that melt at much lower! Temperatures (ζ. Β _Λ at around 100 ^{0 C).} As a rule, the Schnols-3non-ionic alkali metal nalogen salts meet the required oxi ^ QQ ξ; π. the otherwise local stability and the high ionic conductivity in such cells.

This two-six basic procedure was proposed on that

* ·· 1 "·· -» · ■>'· ■: T ^J -! ^ -! - 1—1 (- Λ ■% ■ - ■ "• T - ^ - J- ~ \ ·! ■»! .— "^ -» ti ■) "1. · ■■■> .-. 1 τιη, - m, r. _n -τ-y ^ r , A 4-

iichvei'cl to use as! Cathode, with the proposed Both lithium (or jSat.riun) as well as sulfur ϊώ liquid state

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809837/094 «

“Lithium (or sodium) and sulfur could make attractive Substances for the "use as Blektrodonaatsrlalien, because they have low equivalent weights and theoretically one chemical cell (galvanic cell) with a voltage of about 2.3 V (2.1 V for sodium) can supply »As the active Electrode materials can be in the liquid state under normal cell operating conditions, "both should." immobilized in order to avoid security risks and to ensure the correct functioning of such a cell.

Because of developments in this direction, stierst became suggested that the lithium anode by means of a porous Stainless steel matrix should be immobilized in which has retained all the liquid by capillary action will · This procedure has only partially proven itself al3 proven successful. The lithium is charged during the charging process not completely enclosed (retained), but escapes from the stainless steel matrix in Eorm of subtle epidemics spreading in the electrolyte. The consequence of this is that between the electrodes a Üthiumsuspension enriches, which leads to a self-drainage the cell leads.

Further development has solved the problem of immobilizing the ¹ L-ithiuniaaode. This was arreiciat by ¥ ervandung einar lithium Aluminiuia-Legiervjag or siiior Ijithitim-silicon alloy, the boi the before ^ eschlagoneii ^{B-3-tti'ib3:;} o'nr) 5ra; cu.T · '7- ;? ir lot. 2 \ 'vvr'i j ^ sj ^ -ü ·. "- ^ a _; .:.-.-, I I'Lv-ϊ- ϊ> gierungeii over a wide range of concentration vs-rvijr.dst can be and are good electrochemical behavior on

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The problem that remained to be solved, however, was the problem of immobilization of the sulfur cathode. At operating temperatures of around 300 ^° C., the vapor pressure of sulfur is considerable (around 50 mmHg). The result is that the sulfur evaporates quickly during use and that cells in which cathodes made of molten sulfur are used therefore have a short service life. The only relatively successful proposal for solving the problem of schismeliriaobilization was that of using the problem; bypass transition metal sulfides such as FeS or SU.

However, these proposals have certain disadvantages. A ₂ system is highly corrosive and therefore special materials, e.g. B »Kolybcian, to be used for the strora collector of the cell. PeS is less corrosive than PsSo » ^e s, however, has a significantly lower theoretical energy density than PeS2 * An FeS ₂ cell has the further disadvantage that it results in a two-stage discharge reaction. In addition, the depletion of both PeS and PeSo during the charging and discharging cycles can lead to mechanical breakage (failure) of these cathodes _i _

The present invention relates to new cathodes for electrochemical (Galvanic) high temperature cells, as well as new ones electrochemical ** (galvanic) high-temperature cells that operate at temperatures above the melting points of the cells used electrolytes should be operated.

The subject of the invention is a! Cathode for a high temperature cell, which contains an electronegative element from the group sulfur and selea as well as a molecular sieve carrier,

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in which the electronegative element is sorbed and in which the electronegative element remains during use of the cathode is held back (held) in a cell »

The invention also relates to a method of rigid production a cathode for a high temperature cable, boi de ~ n an electrenegative element from the group sulfur and Selenium sorbs in a colicular sieve carrier, which the elsctronegative element during dex · use in a? - 'cell holds (holds back), xmd the molecular torsisb carrier in oineji porous cathoic cup or case accommodates "

The molecule may be such ar portafilter that feöbh'ilt qt an effective amount of the active elektxOchemisch elaktronegativen element for one such time period (^ .luiMckhält) "dis sufficient vzi the. Effective operation of the cathode izi yiner cell for a reasonable period of time ru o: i.-oögl "ichea"ZvscX'-näßig, however, the '! Rager is such a;., Which - the electrochemically active electro. _nar: v s.tive Eisnicint; uring the use of the cathode in a rope, for which it is intended, in.nexrhalb normal Betriebstypr ^ aburbereichs dei * cell ντΛ irahrcrad without substantial loss' of a suitable Re-iebsdauer the cell Eurückhäl- c (holds).

Molecular sieve carriers point to molecular sieve cavities in ΙΓι> πλ of cages, porna or canals, with the nohlxvluvna Einju?. \ O; o (j? En3t.3r) aufwoison, which in axe hiTi-r-iärirühroa. Dia G-rö ^ e ö y; c

an entry of sulfur or bees at 02; en in dio H '; hlrä \ iiüe to err.possible uad the cavities nuts so ssiti, d.?.L the Sulfur or Selenatoma therein fost ^ ehalton (^ ux-ückgiihilt-o ^)

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can be.

Obligation to be bound by any theory, it is believed that when sulfur or selenium atoms enter such a molecular cavity of a suitable molecular sieve, they are caused by forces which are primarily van d-3r Vaal-type acts to be held in the cavity. In addition, it is believed that sulfur or sslenafcotae, where this is possible, form incorporation elements in suitable primers and that these ring or chain structures can remain intact and coherent during use of the cathode. If this theory is correct, it follows that the volume of such hanging or chain structures alone would be sufficient to prevent their escape from the inlets (SNrastezrO aer iaolecular cavities of suitable molar calarsi carriers during use.

In order to be effective as a cathode, the ions suitable for the cathode according to the invention must allow easy access to the sorbent sulfur or brine, which may be during the use of the cathode in a high-temperature cell of the pail. Dai'aus says that the cathode da.s Hindvirchdiffundiex -en of suitable ions dua: ch must allow the same and that the molecular sieve carrier therefore act as an ion conductor or are so nv.H, v / enn ex ¹ doped with the electro-negative element is.

Under a "cioti.3>: caj.i liülülaxlarcsiebenxv.gsr" is to be understood, ■ '.-'? . [■> ■ - .r'i. "^ · .I.: ·. '." ·: · \ I ¹ I-. ■: - ■ "u- ^ j Λ""; 1ν -> τ '\ - ϊ''ΐ · α \ -. ^ Λΐ.νΊΓΐ ia ^ s ^ y ^ A contains sorbed.

Ib all'-eritjifi & n is the Lsistu.n ^ 3veraögeii of a cell in which

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Such a cathode is used, the better, the higher it is is the ionic conductivity of the cathode. Although the ionic conductivity is less important with a two-dimensional Cathode, should for a three-dimensional according to the invention Cathode of the molecular sieve carrier are chosen so that the Ionic conductivity is at least sufficient for effective operation and preferably as high as possible. In order to be able to work effectively as a cathode, it must be electron-conducting be.

The molecular sieve carrier must therefore be chosen so that it is sufficiently electron-conducting or that it is sufficient It is electrically conductive when it has an effective--) Hange of sulfur or contains selenium, as may be the case if this is sorbed therein. If not, save the Cathode has been incorporated into an electron-conducting Hateriel, This aspect is discussed in more detail below »

There are different 2 types of natural and synthetic Molecular sieve materials are known and they are used in Gro.Seta TJt.-fang used in industry for cleaning, washing (removing) and separation. Because of the need for these materials are carefully examined and new molecular sieve materials are currently being developed and manufactured worldwide »

If one considers various factors such as z, 3 »the size of the access (window), the size of the cavity, Eq

ability, an electrochemically effective amount of sulfur or S.ilon. su sorbieren (absorb) »as this can be the case, and the ability> the sulfur or · the brine among the

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Its operating conditions to retain (hold) taken into account, it will stall an approximate guideline for the selection -of Molekülarsieb carriers for the particular application szvxecke according to the present invention "Other factors which may serve as a guideline, to the degree of porosity, the density , the accessibility (availability), the mechanical strength, the stability and the electronic conductivity of a doped molecular sieve

On the basis of factors like these, molecular sieve materials, ti ie, for example, carbon molecular sieves, composite carbon-fiber molecular sieves and certain sorbent substances (natural or synthetic minerals), such as zeolites, noäifisierto zeolites and zeolite-like substances into consideration get sucked. "

According to one axis of the invention, the molecular sieve carrier natural or synthetic zeolites or modified zeolites that are physically or chemically modified are, however, still suitable molecular cavities for the inclusion and retention of the electronegative element have, contain or consist of.

: a spoken here of a cathode according to the invention which contains a zeolite as colocular sieve carrier or consists of it, it always refers to a dehydration Z-should,

In the!; Er dsm term 'Zeolite' here is the class of crystalline or amorphous natural or synthetic materials su vöi'jfeehQn, the aluminum and silicon in exactly

BATH ORIGINAL

contain the same types of hanging parts, they contain their analogues. For a more detailed definition and discussion of zeolites, reference may be made to the publication of the International Union of Pure and Applied Chemistry, "Chemical Nomenclature ₅ and! Formulation of GoTapositions, of Synthetic and Natural Zeolites" from January 1975. Zeolites usually contain moving water molecules; which are removed by l / arnae and / or evacuation, in allgamainsn revaraibal, vrerden köruasn «Zeolites have in the cone a well georciasta inneiistrukttir _s they have, a high inner Oberxlachangx'öSe and are characterized by the presence of a multitude of regular arrangements of molecular cavities.

It is known that zeolites are in their hyäratisiorten sOrn has been represented by the following structural formula

v / orin M is a cation with the valence η and Σ and Y vono mean independent variables that are a function of 3u.saui ~ tr. definition of the Angsai language and the type of horn division are,

During an execution the inventor can dor HoIs ^-1 CaIcj?

siöbtrö-ser dehjdPc-.tiaiwrte Zeolitki * i3tall3 en ^ haltün odor

from this "o-iistshenj those from the group dex * in the! Totur vorkoi ■> X ' ^a --ü'3.en zeolites, such as Faa.jaöit and Srionit, νχ>, Λ from egg · G-lttt

Zeolite 5A, Zeolite 15X or similar structure is selected ■ v / er den.

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The Z-eolit 4-A has the structural formula:

where the value of X can vary. The zeolite 4A has one Zxigangsdurohmesser (penster diameter) of about 4 A units ten and a cavity volume of about 1000 cubic units,

Da.c zeolite 13 «has the structural formula:

where X can vary over a wide range. The zeolite 1JX white molecular cavities with Duorchrriassern of about 1 ;; % - Eirüii ¹ it on on *

E-3X E; rücl., 3ichtig "Uiig discussed above selection factors that ale Guideline for Auswalil of Holelcularsiebträsers serve könnsa ₇ would be expected au that the Seolit 4A is a suitable carrier for Sch'.iefel The zeolite 4A, namely a window diameter of about 4 Å units, while sulfur has an atora radius of about 2 Å units. In addition, it was found that the zaolite 4A has an axx-free ionic conductivity when doped The Zeo3.it 4A. has a sorption rate for sulfur in the range of about -200 to about -250 kcal / ha when the sulfur is in an S-membered single or set configuration. This heat of sorption was achieved in the absence

riä on the operating conditions in a working cell. It serves, however, as an indication that the 6, ar zeolite 4-A absorbs sulfur during the use of the cathode

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within the 3 Bsbriebsteraperattirberelch.es an Iloch temperature salle hold back (hold on) should and also not be essential Loss of electrochemically active sorbed sulfur should result during normal use. this has been confirmed experimentally as discussed below.

In selecting the molecular sieve support, it is assumed that a heat of sorption of less than about -20 lccal / g-atom for the sorbed electronegative element should be sufficient to ensure that the electronegative element is retained (held) so that the cathode is in a cell can work effectively »However, a Kolelcular sieve carrier is useful selected which has a heat of sorption of less than about -160, preferably less than about -200 kcal / mol Sq or Seo in either a P.ing or I-chain configuration 8Ai points. From the above results; that there where an electronsgative element with a heat of sorption of -200 kcal / mol is sorbierc, this is more strongly sorbed and is retained (retained) more strongly than where it is sorbed with a sorption heat of -160 kcal / hol.

Suitable zeolite crystals should have a sufficiently high physical Have strength for effective use in a cathode. It was also found that doping Zeolite crystals against electrochemical deterioration during repeated use as a cathode in a cell ausx'eic-henu constantly oind,

Physical or electrochemical failure of the doped Zeolite crystals therefore do not belong to the pakboren, the essential, if any, sum of failure (failure) of a

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Zslle contribute in which the cathode according to the invention is used will.

It should be pointed out that the metal cation of the zeolite, whether doped or undoed, can in general be replaced by other ions in the course of an ion exchange process. If such zeolites treated in an ion exchange ^! * Are used as Eat ho "de α in Zollen, the substitute cations represent the olektx-ochean reactants of the Eatho-lon, the cathodes tend to be physical and / or ch .suiscb.5ii Failure during the use of the cells. This is caused by the fact that the zeolites treated in a loaenaustaxi3chev represent an integral rope of the cathodes,

.'The collapse (the Yeroagori) of the Eat hods is therefore a main falctor, the anger Yex'sa-gen is one of them. Cell contributes in which a zeolite treated in e.inen lone.aaixst aas rather "treated zeolite is used as an Eathode. In addition, this 3iisajiasnbrucli (sewing) prevents an effective recharging of such a cell, which prevents it from being used as a selective cell - / ollig; useless bsx vrird »

This is zv in direct contrast. of the present invention, in which the zeolite represents an inert framework for the cathode and does not participate in the electrolytic reaction -tro-

Aspect should be taken into account when choosing the ilolekularaiobt.r'iger for use in the implementation of the according to the invention.

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It is known that zeolites are generally ion conductors but they are generally poor conductors of electrons. It is also known that when sulfur and selenium are not used in a molten state, represent bad electronic conductors *

It is therefore to be expected that an inventive, ^ atLiode, which contains sulfur or selenium, the "for example in an Ilolekularsiebträger in i'oroi of a suitable zeolite, is sorted, is a poor electron conductor and therefore requires the incorporation of an electron conducting material, before it can be used successfully as a cathode.

However, corresponding experiments have surprisingly shown that suitable zeolite crystals in which according to the invention Sulfur or selenium is sorbed, xathode.nmaterials form, in which each crystal aasreichende electron conductivity for successful or effective use as a cathode »

Nevertheless, in the ez'fin & ungsgeraäße cathode can, if necessary, or if desired, a suitable electron derive rides material be incorporated zv a sufficient Elelctronenlsitfähigkeit between the one of a crystal within the cathode. achieve thereby the electron conductivity of the cathode zv. to enhance.

The Jcaan process, which is an object of the invention

of the material is worked into the cathode. In one embodiment of the invention, the electron-conducting Any suitable material

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act that is electronically conductive at the operating temperature of the ropes, such as. B. graphite, MoSo or the like. When the elektrcmsnleitende Haterial in Porra of graphite is present, it can have 3? Orm of a porous coating on the Zeolitkristallen or the form of a powder ext the Zeolitkristallen is mixed. The term "porous" refers to a coating that enables the electrolyte to freely access the zeolite pores, cavities or channels *

The graphite layer should be porous and sweckroäßxg should their proportion should be as small as possible in order to achieve effective electron conduction during use, since Graphite as an electrolyte source can wank, polygamy the entry des Elvikt3? olyten to the sulfur or selenium that is present ο a. know, limited.

In practice, therefore, the ratio should be between electrorienliitenden material and molecular sieve carrier so chosen be that the desired balance between Elek- ■ fcrolycaugang and it is electronically conductive during use achieved in a cell.

Another factor is that the total body of the electronic material should be as small as possible to allow a maximum of energy to weight

In a hoilie by VssroucherL that was carried out : f "oirif; -3iligc? 3 graphine powder with 'undoped zeolite crystals

Contained sufficient amounts of graphite and zeolite. It was found that about 5 to about 16 ^c £ graphite are added to the zeolite Küsnen, including a pellet with a practical

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Use to get adequate electron conductivity. If necessary, however, much larger amounts of graphite powder can also be incorporated.

In preferred embodiments of the invention, the Cathode 5 to 60 wt. & Graphite powder contain »

For loosely compacted structures, where the cathode is a mixture of graphite powder and zeolite crystals contains or consists of, when the size of the graphite particles is small, the movement of electrolyte within the cathode is inhibited (retarded) during use, but the electron conductivity is improved and vice versa if the size of the graphite particles is too large is * In practice, therefore, a suitable as Balance to be maintained »

Instead of graphite in ϊόππ. To use a powder, a number of experiments were carried out using graphite in the form of a colloidal suspension. In the tests, relatively low concentrations of the colloidal graphite suspension in water were used for the treatment of zeolite samples. After drying, the treated zeolite was found to be electronexilic and it is therefore believed that there was a grayish coating on the zeolite crystals. must have formed. However, the zeolite crystals can also be coated with graphite using other methods, e.g.

The cathode according to the invention can i.ci. Forai present a same questioning structure or I'tatrix, they vreixn suitably compressed, when she / eICE appropriately V

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^"22 ~ 28 1032Q

It is compacted together or applied to a binding agent if it is in a ti \ dger structure or in a door ^! : lgerniatrij: is held in place when in a porous. Ka'jiio is contained or arranged on the holder or the like.

In a preferred embodiment of the invention, the Insert the cathode into a suitable porous, corrosion-resistant iri denhaltör be ezithaltezi. With one. Example for theeae

un ^ sfort'i of the invention can the Kathoaenhaltex 'dio Fora 3 porous graphite cups or graphite vessels.

the inventive cathode in 5'orE. A verdiohtei7en Kcitnoäe vox'ÜG ^ t, kxmi the liolakul ^ rsiebträger before or after the iiorptica df ^ o elel: tronogative EIeme ■? _ {;:. »s condensed (;; opreLii;) w8rdenv K ^T -3cln.äbi ^ is diy ITardicliton ^ (Pre ^ & iij: ·:. ^) jodocli aurclisofilhrt ;, naohdom the electronei-yitiv ^ element soz · - hiert vrordsn isb. D3.s Hoü ekularsiabniateri.al or the Eafehedci k-3iir! bei.-ypielö. / eioe by a Px-eBvorgatig, by a! The reason for the implementation of this working day is de: e, do that the volume optiniiex-t, the Kiektronörileitbarkeiticke-it er'-iöht vnC the desired '"oria ersougt vsrden. The variety of JiOri - ^ - ebringoverfghren ^ depends on:

(a) <-i #: e style Ges iiolekuiarcisbträ ^ ers and the Arb of DotierunjsriittelD which manifests Oich ia the Durchbruchste ^ reratur and don iasohaniychen .Eigenschaften,

Size cd
(c) the gofordorb electrical electrochemical property.

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By compressing (pressing) the cathode, the contact between the particles can be improved, whereby an increased electron conductivity is achieved. By compressing the cathode, however, the porosity of the cathode can be reduced four-fold and this affects the diffusion of the electrolyte in the cathode during use. The densification of the cathode can be carried out in such a way that cathode disks or cathode pellets are obtained which have sufficient mechanical rigidity that they are practically self-supporting. If the discs or pellets have sufficient mechanical rigidity to be self-supporting, they can be used in a cell without any form of holder. However, they can still be conveniently used in a holder, for example in a porous baker or in a porous case, so that even if they break during use or if the cup or case breaks during use, the method groSaiitoils still remains intact.

The densification of the molecular sieve carrier or the cathode can therefore, if desired, be carried out so that the requirements of mechanical stiffness and improved electron conductivity are balanced against the requirement that electrical access to the electronegative elegant within the cathode during use is sufficient to achieve a sufficient current density.

If the molecular sieve carrier or the cathode is suitable

be that the ratio of volume to mass at the Kntliode is improved. This can achieve further advantages be that because there is an increased electron conductivity

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is the relative mass of the electron-conducting coating material can be reduced, whereby the use of a cathode with a relatively accessible mass is possible is. In addition, the cathode, if it is essentially is self-supporting, easier to handle.

In Yersuchen that were conducted., Destroyed discs were prepared by adding 16 wt. ^C / j graphite powder to zeolite 4A ~ .Kristallen, by thoroughly mixing the same, and subsequently compacting the mixture under pressure. The disks thus prepared were dehydrated untex 'vacuum at about 4-00 ⁰ C (dehydrated), and then impregnated under a YaJcu.ua at 320 ⁰ C n.it sulfur. The analysis showed a sulfur uptake of about 70 ° p? - ^e ü theoretical value. These disks had sufficient mechanical strength that they could be handled successfully;

In a preferred embodiment of the invention, the Cathode has a small amount of Mengerian, based on the electronegative Elemeni ;, a stabilizing electrconegative Seventh included to. stabilize the sulfur or selenium, four these in sorted condition in the iloleicular— Severe present. Bai the stabilizing element can as oicli nn act any element that is electronegative, the SCi-V.-refel— or iSelenatorae can replace the example-wise in a Sohv, or selenium ring or chain structure

r.ial introduced wox-den, which has an effect, the steam pressure the single or chain structure is reduced. Bai den stabili siereixdon elements should be elements that do

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in principle covalent bonds in the sulfur or selenium ring or chain structures.

If the electronegative element is sulfur, the stabilizing element can be selected, for example, from the group selenium, arsenic, phosphorus vcaä antimony. If the electronegative element is selenium, the stabilizing element can, for example, be selected from the group Sulfur, arsenic, phosphorus and antimony are selected.

It is believed that by incorporating it in small quantities a suitable stabilizing element in a cathode, the vapor pressure is sufficiently reduced, so that when the Xathode temperature increases temporarily the tendency of sulfur or selenium to evaporate is reduced as a result of a short circuit or the like will.

The present invention also extends to a cathode for a high temperature cell made according to that described herein Process has been established.

The invention also relates to a method for immobilizing an eleki; ronegativsn element from the group of sulfur and selenium for use as a cathode in a high temperature cell, bsi which the electronegative element together with a small proportion of a stabilizing r> s Lc-.

the electronegative element while being used as a cathode is held in a cell (aurüe-kg ehalt en).

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The Er.finciting also extends to a cathode, which contains an electz'Gnagativas element from the group of sulfur and selenium, which has been immobilized by the method described here :.

Sorption of the electro-negative element in a suitable molecular sieve support can be effected in any convenient manner. Thus, for example, the molecular sieve carrier can dry or dry for a longer period of time under vacuum with an increased temperature under vacuum, and at the same time the sulfur or the selan, if such a condition is present, can be untex ^ vacuum at elevated temperature longer since dried, you can then citsinander mixed under vacuum, and be kept sufficiently long at an elevated temperature to produce a aiisreichs-NFLI * sorption of Schvref'els ¹ or selenium in the co 1 elru 1 ar si -3b t r-ä ge r su g; e * ä hr 2. <s i si; en.

Bi ö ecfinduagscj-ev.iißs cathode can be eadet both in primary scoops and in secondary se 1.1 en. Its main area of application is, however, the area of the x / iederavxfladb.aren secondary cells, which, prior to the present invention, is therefore based on an optional cell which contains as an electrode or a cathode as described above. The cell may be any goeigns-th anode scvsckmäßig z. B. an anode in the ioria of an alkali metal or an alkali metal Lesiercuiga anod 2.. ^ Jtit b old en.

In a ¹ before ^ ugton execution form for the invention, the Λ; ~.-J ': -1 -rjr · 7 "ri ^vi ·""!' ^: _ ■ _ ν ~. "". ^} I "I. *". 'T—') '!' ■ ~. ^> 2T ' ^1. """! ¹ "^."! T ¹ I Vt'OiilO C / «^ 3" C \. ' ⁿ ^ i ^1. "-"'". eirior Li.thiuin-Alunip.iuia-Legieruri.ss- or a Lithium-Siliciuai-Legieruiigs anode are present. Me cell can be any suitablea electrochemically \ ^r ortreslicho.n (coapatible)

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Contains electrolytes. In a preferred practice of the invention, the electrolyte may be in the form of an ionic molten salt electrolyte that is melted within the operating temperature of itself. The ionic molten salt electrolyte can a lithium ~ Aluainiuachlorid-Systen.s available, which melts at about 100 ⁰ C, for example in! Porra. In another example, the electrolyte can be in the form of an alkali metal halide electrolyte3: 7s teas vox'liogen, which resounds at a temperature above about 20 ° C "and generally much higher. Ausführungszorin the invention, the electrolyte solution may be a mixture, preferably a eutectic Hisclmng from EJ -LiJ, SGL LiCl or the like _not contain "Bai another bevorsv.gten AusführuagsiOrpi Erfindmig of the electrolyte may be aasoziiert with äehydratisiorten 3eolitkristallon. In this AusführiaagsforiA the deyhdratisierten Seolitkristalle kömien sv / ockmäßig CIIB thorn electrolyte impregnated his "In this AusiünritagsiOrn can Stolitkristalle as geeignetex ¹ Tx'äger for the electrolyte in its geschüiols ea & xi Zustaad v / hile the use dienen-

The cell can contain any suitable form of electonic separator. In a specific embodiment of the invention, the Eleki; rod.3P separator can have a completely; dehj'dra / hj.sierte layer of goeignoten Soolickristall ^ n av: X contain the cathode or bsstshon from it, in ö.ie & ep execution i'ora ο. '3aitfcol) fvr rinorvrunschte "Reulcbion ^ produliitt; ^T ''"ibr; r \ i dir ν ur; <ün.J. "Aiig cu'.d iüx · a.addi-a Zalivwrgix ^ uagd ^ iau ^ riitiloa üi: onen.

The cell according to the invention must be in an inert atmosphere

BAD ORIQIiSJAL

be held, "which is expediently an argon gas atmosphere can act .. The cell according to the invention can be in any suitable material, for example in one corrosion-resistant material with a small weight be included .. In a preferred embodiment of the invention, the cell according to the invention can be in an inert gas atmosphere enclosed in a stainless steel shell be.

It should be noted that the cells of the present invention can easily be combined into a battery in any required manner can be. The present invention therefore also extends to a battery that has a plurality of interconnected connected cells as described here or consists of it.

In the following, the invention is more preferred and exemplary by way of example Detailed information with reference to the enclosed Drawings and with reference to certain experiments, which were carried out, described in more detail. The accompanying drawings show:

3? Ig. 1 see a schematic. Cross-sectional side elevation of a AxisführuxLgsf or ei an inventive, wiedex'auf- Iado3.ren high temperature lithium / sulfur cell that contains a cathode according to the invention;

Fig. 2 is a partial cross-sectional side elevation of a V: .3UCLe ^? 11.), Ci ^ suv Durcliiführung here b-s ^ ehxaebenen Experiments was made and used;

. 3 sin diagram, in dea the voltage against the

809837/0945

BATH ORIGINAL

Current density in the test se Ils according to F'ig. 2 applied is; and

4- a typical charge-discharge Xurve for the Verstichszella according to Pig »2,

809837 / 09Ü5

»30 -

In the FIG. 1 of the accompanying drawings, the BoZug3 zx ffsr 10 generally designates a rechargeable high-temperature lithium / Schv / efel cell according to the invention which contains its cathode. The cathode 12 consists of a molecular sieve carrier in the form of dehydrated zeolite 4A crystals with an electronic element in the form of sulfur adsorbed thereon, v / o bsi the zeolite 4A crystals, the do η sorbed Schv / eFel contain, are mixed with the dried graphite powder in a knsssnvsrhtil'cnis of 1: 1, whereby one mixture is disfigured. Dlg i \ ischung 14 is located within a porous graphi-Kctho-Janhaltergo housing :; (-bechers) 16, into which she was firmly pressed! is. The cathode holder housing Io has a c! A.raii fastened to electronically connected terminal IG. The cell 10 contains a corrosion-resistant cylindrical housing 20 made of rust-free steel, which closes (seals) the cell 10. The housing 20 has a bottom plate 22 and a cover plate 24.

The cathode 12 is arranged centrally within the cell and it rests on the base plate 22 on an insulator pad 26. The ? Isola torpols ter 2 <S expediently consists of boron nitride, oils Kcrhhoc'.e 12 waist a connection terminal 18, which extends ei üdici'i band ajxch the Dj ck ρ la t te 24 through. The connection 18 is by means of an insulating sleeve 28, the zv / eckr.viOic! '1', ¹ S e'.nrT k-iruiniscr .-: n ["■ 'ι t ^a . Riπ 1 hs is, is insulated above the cover plate 24.

The cell 10 contains a cylindrical lithium-aluminum alloy

BATH ORIGIfSJAL

809837/0945

Anode 30, which is in contact with the housing 20 and a on the cover plate 24 attached negative terminal 32 has. The cell 10 contains a eutectic potassium iodide / lithium iodide mixture 34 (with a melting point of 260 C). The cell 10 was under an inert argon atmosphere closed (sealed,),

In Fig. 2 of the accompanying drawings, the reference numeral 36 generally designates a high-temperature presetting lock which is used for Experiments made and used as follows described were carried out.

The cell 30 consists of a housing 38 made of stainless steel with a bottom plate 40 and a cover plate 42, which means Screws (bolts) 44 is screwed to the housing 38. A Sealing ring 4: 3 ensures an effective seal between the cover plate 42 and the housing 3ö. Cell 36 also contains one Cathode 48.

The cathode 48 consists of a porous graphite cathodon housing 50 which contained the appropriate cathode mixture 52 for the experiments carried out. The cathode 48 furthermore contains a porous graphite cover 54 and an electric sensor in the form of sinusoidal elements 56 made from non-refractory zeolite 4 A-Kri ε ta Ilen, The Ka "chads 4P is in a ^l \ lj - niniu.5ioxi ^r ! - :! 'ihaus 58 αη ^ ο? Ηη ~ h. J-? ". c \! ~.

The insulator against the stainless steel housing acts and has an electron-conductive connecting rod 60 which extends through the cover plate 42 therethrough. The connecting rod 00 extends sealingly through the cover plate 42 and

809837/0945 _BAD original

he is opposite the same by means of a ceramic isolator sleeve 62 isolated.

The Zo ¹ Ue 36 also has an anode 64. The anode originally consisted of a perforated aluminum housing όό (purity 99 yl), ck <3 was filled with about 2 g of lithium rivet and a lithium-aluminum alloy was formed during the subsequent charging cycles. The lithium and aluminum masses were chosen in such a way that a Lejiorü-ngszusani.ViSnitzung with 7 to 50 atoms of lithium arose. The anode 04 contains an aluminum rod connection 70 which extends tightly through the cover plate ^ 2 and is insulated from the same by means of a Keraiiukisolatarhülso 72. L'-ji cbr \ h ηdhaOung and when assembling the cell 36, the various components were treated in a closed argon atmosphere. The cell 36 contains an electrolyte 74 in the form of a eutectic mixture of lithium iodide and potassium iodide with a snap point of 2 <5G C »The porous graphite cover 54 had a thickness of about 0.5 cm and a geometric surface size of about 3 cm.

The electrod inseparator layer 56 consisted of completely dehydrated Z & olit 4Ä-! Crystals, which were moored within an approximately 3 mm thick cloic'ir.ib'L.icpri layer, the exposed surface of the Ka + .hoci-j 43 to cover. The fully dehydrated 7'-olir ?; , -ri'ächt also acts as a ruin cleaning agent (removal agent) for undesired reaction products and impurities. In other attempts, boron nitride powder or a piece of cloth (cloth) has also been used successfully as a separator material.

8-09837 / 0945 '

BATH ORIGINAL

The molecular sieves used in the tests passed from synthetically produced dehydrate zeolite 4A, 3A and 13X crystals. Although the zeolite crystals after some conventional processes for the experiments carried out, they were produced according to the ancestor of Charnell, as stated, for example, in the "Journal of Cryshai Growth ", 8, 291 (1971). The so prepared Zeolite crystals had an average diameter of about 10 microns.

Although there are a number of methods that can be used Zürn sorbing of sulfur or selenium to dehyclratisiertein zeolite, but oos method should preferably be selected so that a maximum amount of Schwofs! or selenium is obtained if this (this) is to be sorbie.ct from the dehydrated zeolite. One of the most effective methods is to impregnate the dehydrated zeolite in the gas phase, in which case the sulfur or selenium is heated until a gas (vapor) is formed, which then comes into contact with it and the dehydrated one The sulfur or selenium atoms, if present, enter the molecular cavities of the molecular structure in the ice, since they are not specifically the locations of any atoms or molecules present in the Ingesting zeolite.

Although it was found axe sorption of gravity! or Selenium on a dehydrated zeolite can have the effect that the zeolite lattice structure is somewhat distorted is due to of the experimental results obtained assumed that a

BATH ORIGINAL

281Q320

Zeolib during the use of the cathode in an inch Maintains physical structure and during normal Use does not break. On the basis of the tests carried out, it was also found that the doped according to the invention Zuolite crystals during repeated use of the cathode in a ZaHo against electrochemical damage (destruction) are persistent.

There is a clear indication that iietailkaticnen, which form an integral part of the non-dobierton ZeoIitkristalle, are not substantially affected and no change in these doped Zeolitkriütailo AASS their Ox / dationsziJotundes during use al :. Cathodes in cells u.ntorlisQ ^ n. There is therefore an essential difference between the continuation passport doped zsoliton w, \ a don ni fc producible Ibtalliorien ousc; 2 ~ exchanged zsolitrr.otex-ialien · »- · ηη such ion-accurate zeolite materials as iCaclioJlisn Cell used to make the reducers advised; !! ions dos electrochemically active element of Kohhode dnr. The consequence of this is that Zsolit physically and / or electrochemically breaks down during use, which leads to the turning of the cathode. CLglo. '. Cit dias iü! In the case of a pri. Door he already '.ve a ent.lic h his k'-inrif i- ~ t ei ic · ο b-33Oiirlers serious in the case of ainor secondary «zoIls (cs'or v / i; ic! -.) rnuflt "it! ioaron Zalls).

For the preparation is Kathodenniischung for the various experiments the zeolite crystallites produced wurcbn for 24 hours b:; i ec \ / a 3:. '; 0 C and 10 Torr dehydratisierb (dehydrated). GieichiTäiti'j v; urde finely divided sublimed sulfur about 35

809837/0945

BATH 0.1! 3! TIMES

Dried for hours at about 105 C and 10 Torr »The both samples were mixed together thinly under vacuum and held at about 300 ° C. for about 100 hours, then • They were fetched for about 240 hours at 27C and finally for about 90 hours at about 115C, with the Sulfur was either abdsstillierh or separate crystals that formed with those dos zeolite-s in the form of a loose Powder were mixed. The zeolite crystals were similar 'Wise doped with selenium. The at Fangliche iMipräcjni in this case the door is about 600 C,

It has been found that the sulfur or dos selenium is effective in the zeolite crystal. !! lattice penetrated and within the lattice Was firmly held back. After the heavy fuel oil or the 5slon was sorbed by the riolokularsiebtrcifjsr, the Cathode mixture 52 produced by adding dried, purified graphite powder in a Hassen ratio of 1: 1, thorough mixing and subsequent pressing (compression) of the cathode wire 52 into the cathode housing 50 The cathode mixture 52 consisted of tests carried out 3 g of zeolite-sulfur crystals or zeolite-Seisn-Iiristallen and the cells had capacities of about 1 hour.

In the experiments carried out with these lines, after the rows to their required operating temperature above the melting point of the molten ionisclvi.n Süizsioktroivt'jri had been brought, an automatic charging / discharging « Cycle started with constant current and the relevant electrical

809837/0945 bad original

Parameters were measured. The operating conditions were in similar or the same in all cases as follows:

Charge / discharge current anode

Cathode electrolyte temperature ο b & re A bs c ha It s pa η π υ η g lower cut-off voltage

50 mÄ / cm Li-Al alloy doped zeolite / craphite LiJ / KJ eutectic 300 ° C 2.3 V 1 _r l Υ

The expression "upper b; iw. Lower holding voltage ¹¹ stands for the oh-sre or lower limit bio to which the cell was charged or zn Όλο den."

The average results of the various tests carried out are given in Table I below. As far as these experimental results are concerned, it should be pointed out that these are largely preliminary results and that slight changes are to be made if they are repeated.

809837/0945

- 37 Table I.

system

open circuit voltage (V)

Short circuit current
(inA / cin)

Energy density (Watt.5td./kg, based on zeolite / S (or Se) + Li alone)

maximum power (watt / cm) Coulomb efficiency (? Q

Sulfur (or selenium) (utilization in %)

Internal resistance
(Ohm / cm)

Number of cycles

approximate number of operations * - hours

A / S
1.80

1100

404

0.5

90

62

3A / S 13X / S

1.80 1.80

500

130

0.4 0.2

60

61

0.5 1.6 3.6 300 30 * *) 5 > 3600 36C 50

4A / Se 1.70

500

280 0.2 99

65 3.4

500

*) The theoretical 5chv / efe! Recording was unknown

**) The cell was at the time of compilation of the Results still in operation.

Because of the experiments carried out with the Kathoclan mixture obtained from zeolite 4A crystals with sulfur sorbed therein passed, the diagrams of FIGS. 3 and 4 were produced.

In Fig. 3 the results are shown in graphic form,

dia for cii

t-Sp'jnm;n.; j, π υ- ^ j bear

ie St.ro, ·! Ji ~ h ~

were obtained. These data were obtained with complete charged cells and the individual measurements were carried out over 10 second periods »

BATH ORIGINAL

4 shows in graphical form a typical charge / discharge curve, in which the cell voltage V (including the IR potential) is plotted against the time in hours.

It can be seen from the average var exposure results reported in Table I above that the open circuit voltages of the various cells do not vary widely. This shows that the activity of in ά? Η different Zeolitstruktursn hardly varies captured sulfur as a function of) selected Zeaiiten, k'as do η short-circuit current is concerned, this depends inter alia on the Innenwiderstar.d the cell. The internal resistance, for its part, is clearly influenced by various factors, such as the porosity of the electrode housing and the distance between the electrodes.

In the experiments carried out, the cathode housings had a porosity between 30 and 50 % and the distance between the electrodes was about 1 cm. This shows that the innon resistance of the various cells had not been optimized. With an optimization, lower internal resistance values would be expected and this would lead to improved short-circuit current values.

What the energy the. Iris and the words for sulfur exploitation the values given in Table I are based on this all based on experimental data. There were invoices ourcii- * performed using the average discharge stress together with dan received on unloading Capacities (ampere-hours). The observed energy densities

809837/0945

BAD ORIQINAt

79 _

depend on the use of sulfur. Viie cus the table. 1 apparent, the values for sulfur utilization were rather low recorded.

It is believed that by improving the manufacturing technique and the purity of the raw materials, the sulfur utilization can be improved up to about 80% or more? This leads to a substantial increase in the ensemble density. The respective fourths for the Schwsfslausnutriursg for the zeolite SA / sulfur and Zsolite ^ A / salen systems are based on the assumption that these zeolites sorb the same number of sulfur and carbon atoms per unit of form as in the case of zeolite 4 - \ / - Sulfur. These formulas are as follows:

4A / S: Na ₁₂ Al ₁₂ Si ₁₂ O ₄₈ -S ₁₆

3A / S: K ₁₂ Al ₁₂ Si ₁₂ O ₄₈ -S ₁₆

4A / Se: Na ₁₂ Al ₁₂ Si ₁₂ O ₄₃ -Se ₁₆

Chemical analyzes have shown that only ½% of the theoretically possible sulfur impregnation of the zeolites is achieved in practice. The fourth for the sulfur utilization, as given in Table I, are based on an ICO / jigsn Schv / efolimprägnisrung. These methods can, as may be expected, be improved under coordinated conditions.

The maximum Lei-i; unö depends on the btromdichue, which, as mentioned via oban, has not been optimized. It is, therefore, to be acquired that the maximum losses can be improved in an optimized system.

809837 / 09A5

BATH ORIGINAL

The Coulomb efficiency is a measure of the ratio of charge added to charge removed. Except for the Zeolite 13X system are the values given in Table I. externally satisfactory. The relatively bad value of the Coui.Jinb efficiency for the zeolite 13X is possibly attributable to impurities that lead to electrolysis within the cell, or to an internal loss of charge (charge leakage).

As for the number of cycles, the cell in the zeolite 4A / sulfur cathode system operated continuously for about 100 cycles (more than 1200 hours) without any significant deterioration. After that, little deterioration (deterioration) was observed. After 300 continuous cycles, the energy output had decreased to about 50% of its initial value. It is believed that this deterioration is due to non-intrinsic corrosion and to breakage (failure) of cell materials as a result of contamination. It follows from this that once the target materials according to the invention have been optimized, the usefulness of a cell is considerably higher.

As for the number of cycle η in the zeolite 3A / sulfur -! (Athode system concerned, after 30 cycles the gc-inebanan V / ^ rt in Table I: · obtained-

The those. Cell containing zeolite IGX / sulfur cathode worked only 5 cycles before it failed.

809837/0945

ORIGINAL INSPECTED

As for the zeolite 4A / selenium cathode system, so were after 50 cycles the fourth for the cell parameters given in Table I was obtained. After the cell another 20 cycles had worked long, no significant deterioration (impairment) was found.

Although the tests carried out are only of a preliminary nature and were carried out with relatively small test cells, they give an indication of certain advantages achieved by a cell according to the invention and by a cell according to the invention Cathode can be achieved.

It is known from the literature that a battery for one electric vehicle drive ideally the following conditions should meet:

1. It should have a good performance-to-weight ratio, 2; it should have a good energy-to-weight ratio,

3. It should allow a large number of charge-discharge cycles,

4. It should be safe in the event of an accident

5. it should be cheap to manufacture,

6. The above materials should be available in abundance,

7. it should have a high charging speed or rate,

8. It should have a single-stage release cycle> ~ υfwo.i.?; 3n _?

that is to say that the voltage would be approximately constant during the discharge cycle, and

9. It should have a long service life.

• 09837/0945

ORIGINAL INSPEGTED

These requirements are described below with reference to the preliminary test results given in Table I above, as they were achieved with the cell according to the invention, the zeolite 4A / sulfur system as a cathode contained, discussed.

As for the first requirement, the ratio depends on Power to weight to a considerable extent, from d # ffl "" \ ......

Zellaufbnυ (as well as active components used by d-sn) insofar as the active surface area of the electrode is a the important limiting factors bsi the energy output of the System is. A Zcolit / Sulfur Kathoce acts as a three-dimensional one Electrode, since it prevents the Electrolytes allowed through the cathode and the ones trapped in it Sulfur is therefore actually freely accessible to the electrolyte. It also has an alkaline acetyl-sulfur battery an extremely high theoretical energy.

As far as the ratio of energy to weight is concerned, the existing literature shows that in cells, the lithium-silicon-alloy anodesn and contain the cathode types indicated below, the theoretical and practical ones achieved Energy densities in Viatt hours / kg are as follows:

Cathode theoretical energy - achieved to energy

density (V'att χ h / kg) * seams (Va ti χ SU J

453 84 650 150 2OSO 300 ■ +

FeS

FeS ₂ liquid S

* Energy density, based only on the mass of the active electrode material
** Energy density based on the total cell mass.

809837/0945

The literature shows that where the cathode contains liquid sulfur, it is retained in a porous matrix (noted), rapid loss of sulfur leads to rapid disintegration during use, whereby this cell type becomes unattractive as a secondary cell.

In a zeolite / sulfur xathode according to the invention, the theoretical energy density of 035 watts χ hrs / kg, only bazogen on the masses of the zeolite / sulfur cathode and a pure one Lithium anods.

With a sulfur utilization of 60% when using a lithium-silicon anode, an energy density of around 160 watt χ hour / kg can be achieved. With a sulfur utilization of 90% , the optimum energy density that can be expected would be around 240 V / att χ hours / kg. B _a i these figures take into account the total weight of the cell, which is based on the available data taken from the current literature.

In the case of a cell in which the anode consists of a lithium-aluminum alloy, for a cell according to the invention with a sulfur utilization of 90 % this would be a fourth of 2'M-V.'att χ hours / kg or 143 Watt χ hours / kg to be expected with a sulfur utilization of 00 / o.

Qa cells in which the cathode is FeS or FeS ^. contains or consists of it, are in principle most closely related to the cells according to the invention and are serious contenders for use in vehicle propulsion, the above comparison is statement ™

809837/0945

vigorously and he shows that an optimized inventive Cell one for use in electric vehicle propulsion should have a sufficient ratio of energy to weight.

In order to meet the third requirement mentioned above To achieve a large number of cycles, the sulfur or selenium must be used during the repeated charge-discharge cycles firmly retained within the molecular sieve carrier and the cathode must be mechanically and chemically stable and must not disintegrate or be mechanically or chemically impaired during the repetitive cycles.

The test results given in Table I above, particularly with respect to the zeolite 4A / sulfur cathode suggest that a cathode according to the invention achieve these goals can. A test cell containing the cathode according to the invention was charged and discharged times via ICO without a substantial loss of coulombic efficiency and sulfur utilization cuftrat.

Without being bound by any theory, it is assumed that sulfur or selenium, if it (it) is sorbed in a suitable molecular sieve carrier, such as a suitable zeolite, ι in the form of rings (such as the sulfur in zeolite 4A. Structure) or in the form of chains within the cavities of the dehydrated zeolite lattice. Since the tests carried out show that no detectable loss of time occurs at sulfur or selenium over a reasonable period of time, it is believed that this indicates the rings or chains oaß intact during the charge and discharge cycles and

809837/0945 original inspected

stay cohesive. It is also believed that this is an indication that when lithium ions react with sulfur / selenium during use at the cathode to form the lithium sulfide / lithium selenide compound, the electrochemical reaction occurs within the molecular cavities of the zeolites. As a result, clapj thiumsulFid Li or lithium selenide, which is known to be soluble in the electrolyte. remains within the molecular cavities during use. This theoretical explanation could also indicate that any volume cinderuncans are absorbed by the zeolite lattice during the transformation, which leads to insignificant changes in volume of the cathode itself. Therefore, a cathode according to the invention in a pressed (compressed) Fon ?, resistant to the type of mechanical degradation (disintegration) that prevails in common cathodes.

As for the fourth condition for a vehicle battery, since the sulfur or selenium is retained by the Zeolitan, the risk that the sulfur will come into contact with the lithium anode in an accident to the point of exploding or becoming dangerous is practically zero . This would also be the case in an extreme case if the lithium alloy anode actually touched the cathode.

V.'c3 the fifth and sixth / \ nfordi ~ung to Fcihrz'Si.jgba ttoriiMi For example, naturally occurring zeolites are inexpensive and readily available, while synthetic zeolites are light and inexpensive can be produced. Sulfur is easily and cheaply available

BATH ORIGINAL

809837/0945

Available, while selenium, which is already rarer and more expensive than sulfur, is still on a competitive basis for certain Applications could be used / ended.

As far as the required charging speed is concerned, commercially available batteries should be able to provide a sufficiently high charging speed or. -rate to be maintained, since a cathode according to the invention can be a three-dimensional cathode which has a large, potential surface and since an electrolyte with a high current density can be used.

U'as As for the request to a single-stage Entladungscyclus, the accompanying Zeichnungan is known from Fig. 4 xu erse.hen, daPj the voltage for about 30% of Entladungscyclus remains practically constant.

V / as the service life (service life) is concerned, it is because of the Stability at relatively high operating temperatures expect that the service life or service life will be more than sufficient is, among other things, for driving motor vehicles and for storing excess energy (with low loads).

In order to probe this concept, the was doped with selenium Cell containing Zsolit 4A in a fully charged state 25G hours lnny at the normal operating temperature of the 2ell & held. No significant loss of capacity was observed.

For the mechanisms of storage of excess energy (with low load) in an electrical energy distribution system

809837/0945

network, the requirements for weight fall

path. The requirements for such an energy storage mechanism are therefore generally a high Colulombic efficiency, a high charging speed or rate, the ability to withstand a very large number of charges and discharge cycles, low voltage requirements and safety in case of accidents,

The preliminary test results given in Table I above show that an optimized cell according to the invention, which contains an optimized cathode according to the invention, results in an energy storage olfactory system which can be used both for electric vehicle propulsion and for the storage of excess energy (up to low loads) . 'can be ended. It should also be pointed out that aaR MoIekυ Lars ieΌ carriers are suitable and, in particular, zeolites are stable up to high temperatures (in many cases at more than about -500 C) and are sufficiently light to give good power-to-weight ratios .

An advantage of the embodiments of the invention explained with reference to the accompanying drawings and with reference to the experiments carried out is that a cathode and a cell are created in which elemental sulfur or elemental selenium is effectively incorporated into the appropriate molecular carrier so incorporated, aaii siu Jennjoh are readily available for effective electrochemical utilization and on the other hand coß them during use when required

809837/09 * 5 bad or, g, nal

~ 4-3 -

Operating temperatures effectively recorded therein to be held back. This thus provides an effective solution to the problem of evaporation of the electronegative element during use and you get one in this way Cell with a high current yield (efficiency) and stability.

Claims (1)

lÖ DEUFE L S-CfJÖN DR. WOLPGANG MÜLLER-BORK (PATENT ADVOCATE FROM 1S27-197)) DR. PAUL DEUrEL. DIPL-CHEM. DR. ALFRED 3CHÖN, OIPL.-CHEM. WERNEF! HKRTSL, DIPL.-PHYP. p 3129 Applicant: The South. African Inventions Development Corporation, Administration Building, Sclentia, Pretor ia,) South Africa Cathode for a cell, method of making such a cathode and recyclable materials containing it rechargeable battery P ate η ta η s Ό rü che 1. Cathode for a high-temperature cell »characterized in that the cathode (12, 48) contains or consists of an elelccronegativen element from the group of sulfur and Selea and a MolalrularsieLrbräger in which the electronegative element is sorbed νχιύ in ö .BX.1 flay eloktrorie ^ ativs ElsMa: \ t "· ΊΊαΓ · 3Λά rlar Y-iru-v. ^ - 'ln ^. Hold back the cathode (12, 48) in a cell (10, 36) vf ir do 2. Cathode according to claim 1, characterized in that the molecular sieve carrier for the sorbed electronegative
Elenent one heat of sorption "less than about -20 kcal / g-At οία. 3. Cathode according to .Anspruch 2, characterized in that the Kolekularaiebträger for the sorted electronegative
Elesisnt: In an 8-membered molecular form, it has a heat of sorption of less than about -160 kcal / mol * 4 ·. Cathode according to claim 3, characterized in that the holicular sieve carrier for the aorbierta electronegative
Element in an 8-membered molecular form has a heat of sorption of less than -200 kcal / i'iol. 5 »Cathode according to one of the preceding claims, characterized It is indicated that the molecular sieve carrier contains odse consists of dehydrated zeolite crystals.ru 6. The cathode of claim 5 _5, characterized in daji the present dehydrate Seolifckriatalle in Eorra in -yon represents ITatxir vorkoaaandon Zeolitkristalle.a selected from the group consisting of erionite vn.ä Pau ^ asitkristalle " 7. Cathode according to claim 5 »characterized in that the dshydrafcir-iarten zeolite crystals are selected from
the group of zeolites 3jm.thetischa.a comprising zeolite and zeolite 3An Seolit MA 132-Kx'ista 8. Cathode according to claim 7 · characterized in that the dshydratioiartöii Ssolite crystals in the form of zeolite »kk- BAD ORIGINAL R 0 q Π ^ 7 / Π 9 4 ^ i 9. Cathode after. Claim. 7, characterized in that the dehydrate zeolite kestalia in the form of Zeolib JA crystals present » 1.0. Cathode according to one of the preceding. Claims, thereby characterized as being an electron-conducting material contains which is electron-conductive during use is. 11 «cathode according to claim 10, characterized in that the electron-conducting material consists of graphite powder, that is associated with the molecular carrier iac, 12,! Cathode according to one of the preceding claims, characterized characterized in that it is in the form of a which is produced by compression under pressure (pressing); has been" 13ο cathode n? .Ch eiaesi of the preceding claims, thereby marked as being inside a porous cathodic switch (16, 50) is included » A cathode according to any preceding claim, characterized in that in the cathode (12, 48) is a kleinerar I'L'engenanteil a stabilizing Elektrox-.egativen JIaments I ^1, including the electron ^ sjative Slenenb in. Its states sorbiorben - ^ nd in uor Kabhode (12, 48) during use au stable! οio-c A cathode according to claim 14, characterized gekennzeioimijt that it is at eng elaktronagativen element, inter alia, sulfur-t lisaäo3 and Dafi the stabilizing el ^ ^ ktrone ative Elenenb is selected from the group selenium, arsenic, phosphorus and antimony. 16. High temperature Selle, characterized in that it is as an electrode includes a cathode (12, 48) according to any one of claims 1 to 15. 17 cell according to claim 16, characterized in that it contains an anode (30 »64) in the form of an alkali metal anode . IS. Sslle according to claim 16, characterized in that it an anode (30, 64) in the form of an alkali metal alloy anode. 19 * ropes according to claim 18, characterized in that the Anoda (30, 64) from a lithium-silicon or a Lithium-aluminum alloy consists of A cell according to any one of claims 16 to 19, characterized in that it contains an ionic electrolyte as a molten salt (34, 7 ^) which eats axially molten during use. 21. Customs according to claim 20, characterized in that the electrolyte (34, 74) consists of an alkali metal halide electrolyte. (34, 74) exists. 22 »Sail« to Anapruci ». 21, characterized in that the Electrolyte (34, 7-Ό s - ^ - s a eutectic: ». G-eraisch from EaliumJodid / Lithitragodid or Saliumchlorid / Ldthiumchlorid confirmed. S09837 / 09A5 bathroom 23 * cell according to one of claims 20 to 22, characterized in that that the electrolyte (34.7% was dehydrated Zeolite crystals is associated. 24. Cell according to one of claims 16 to 23, characterized in that that they have an electret separator in Fora one Layer (56) contains dehydrated zeolite crystals, which know to act as a legger. 25 «Rechargeable battery, characterized in that it contains a plurality of cells (10, 36) associated with one another according to one of claims 16 to 24 or it consists of » 25 «primary battery, characterized in that it is a Variety of associated ropes (10, 3S) according to any one of claims 16 to 24 contains or represents the axis consists, 27 · Method of immobilizing an elelctronegafciveii element from the group sulfur and selenium for use as a cathode in a high temperature cell, characterized in that one is the electronegative element together with a smaller proportion of a stabilizing, electronegative element in a molecular sieve carrier sorbed, within which the elecbronogative Element is retained in a cell (10, 36) during use as a cathode (12, 48). 23. The method according to claim 27, characterized in that the electronegative element is sulfur and ale stabilizing element electronegative element selenium, arson, & 09837 / 094S Phosphorus and / or antimony are used. 29. The method according to claim 2 ?, characterized in that the electronegative element used is selenium and the stabilizing electronegative element Ax * sen _y phosphorus and / or antimony. 30. A method for the production of a cathode for a high-temperature Zalle, characterized in that an electronegat-ives Eleasnt from the group sulfur and selenium in a molecular sieve ^{carrier, which holds the electronegative element T} , / uring the Vexn-rende in a cell, sorted and surrounds the molecular sieve carrier with a porous cathode cup (16, 5 ^). 3'U Vsrfahrsn according to claim 30, characterized in that one efaisa smaller Kengwiienteil of a stabilizing end ele? -ctron- <jgätiven. Elements in the electro-negative element incorporated " 32. The method according to claim 31, characterized in that one as electronegative sleasnts sulfur and as stabilizing one electrostatic negative element selenium, arsenic, phosphorus and / or antimony used » 33- The method according to claim 31, characterized in that ni-an as electronegativss element selenium and as sbabilierudss electronegable elsaent arsenic, phosphorus odö.c antimony vari- r ^ nd 3t.