NL8003660A - NON-AQUEOUS CELLS USING HEAT-TREATED MNO2 CATHODS. - Google Patents

Description

* £ i 3sr. 0.29.220 ETiet-aqueous cells using heat-treated MnOg cathodes.

The present invention relates to a non-aqueous cell using a highly active metal anode, a manganese dioxide-containing cathode, containing less than about 1% water by weight of the manganese dioxide and a liquid organic electrolyte on basic of J-methyl-2-oxazolidone together with a cosolvent and a seised solute.

The development of high energy battery systems requires the compatibility of an electrolyte, which has desirable electrochemical properties, with highly reactive anode materials, such as lithium, sodium and the like, and the efficient use of high energy density cathode materials, such as manganese dioxide.

The use of aqueous electrolytes is excluded in these systems, since the anode materials are sufficiently active to react chemically with water. It is therefore necessary, in order to realize the high energy density obtainable by using these highly reactive anodes and cathodes with high energy density, to turn to the investigation of non-aqueous electrolyte systems and more particularly to non-aqueous organic electrolyte systems.

The term "non-aqueous organic electrolyte" in the prior art refers to an electrolyte composed of a solute, for example, a salt or complex salt of Group IA, Group II-A or Group III-A elements of the Periodic Table dissolved in a suitable non-aqueous organic solvent. Common solvents include propylene carbonate, ethylene carbonate and /-butyrolactone. The term "Periodic Table" as used herein refers to the Periodic Table of Elements as found on the inside back cover of the Handbook of Chemistry and Physics, 48th Edition, the Chemical 30 Rubber Co., Cleveland, Ohio, 1967-1968 .

A variety of solutes are known and recommended for use, but the selection of a suitable solvent is particularly difficult, as many of these solvents used for the preparation of sufficient conductive electrolytes to allow an ion migration effect through the solution reactive with the aforementioned highly active anodes.

8003660 2

Most researchers in this field have focused on aliphatic and aromatic nitrogen and oxygen containing compounds in their search for suitable solvents, with some attention given to organic sulfur, phosphorus and arsenic 5 containing compounds.

The results of this study have not been entirely satisfactory, as many of the solvents under investigation cannot yet be used efficiently with high energy density cathode materials such as manganese dioxide (MhOp) and enough corrosive / for lithium anodes to perform efficiently during any period of time to prevent.

Although manganese dioxide has been cited as a possible cathode for cell applications, manganese dioxide itself contains an unacceptable amount of water, both of the absorbed and the bonded (adsorbed) type, which is sufficient to cause anode (lithium) corrosion along with the attendant corrosion hydrogen generation. This type of corrosion, which causes gas evolution, is a serious problem in sealed cells, especially miniature type button cells. In order to keep the total battery powered electronic devices as compact as possible, the electronic devices are usually designed with cavities to store the miniature cells as their power source. The cavities are usually made such that a cell can be snugly placed therein, thereby making electronic contact with suitable clamps in the device.

A potential major problem with the use of cell powered devices of this type is that when the gas evolution causes the cell to swell, the cell can then be clamped within the cavity. This can result in damage to the device. Also, if electrolyte leaks from the cell, it can cause damage to the device. It is therefore important that the physical dimensions of the cell envelope remain constant during discharge and that no electrolyte can leak from the cell into the energized device.

US Patent 4 * 133 * 356 discloses a method of manufacturing a Mh02 electrode (cathode) for non-aqueous cells, wherein the Mh02 is initially heated within a range of 350 to 450 ° C, to substantially both removing the absorbed as the bound water and then, after being formed into an electrode with a conductive agent 8003660 * 3 and a binder, further heated within a range of 200 ° C to 350 ° C prior to its assembly in a cell.

British Patent 1,199,426 also describes the heat treatment of MhO 2 in air at 250 to 450 ° C to substantially remove its water component.

U.S. Pat. Nos. 3 * 871 * 916, 3 * 951 * 685 and 3,996,69 disclose a non-aqueous cell in which an electrolyte based on 3-methyl-2-oxazolidone is used together with a solid cathode selected from the group consisting of (CE),

2C U

CuO, FeSg, Co ^ O ^, Y2 O,. Pb ^ O ^, IngS ^ and CoS ^.

While the theoretical energy, ie, the electrical energy potentially available at a selected anode-cathode couple, is relatively easy to calculate, there is a need to choose a non-aqueous electrolyte for a couple that it allows the actual energy generated by having a composite battery approximate the theoretical energy. The problem commonly encountered is that it is practically impossible to predict in advance how well, if at all, a non-aqueous electrolyte will function with a selected torque. Besides, a cell should be understood as a unit with three parts: a cathode, an anode and an electrolyte, and it should be understood that the parts of one cell are not predictably interchangeable; parts of another cell for manufacturing an efficient and active cell.

It is an object of the present invention to provide a non-aqueous cell, including components including a 3-methyl-2-oxazolidone-based electrolyte and a manganese dioxide-containing component, in which the water content is less than 1% by weight based on the weight of the manganese dioxide

It is another object of the present invention to provide a non-aqueous manganese dioxide cell using a lithium anode.

It is a further object of the present invention to provide a non-aqueous lithium / MhOg cell using a liquid organic electrolyte consisting essentially of 3-methyl-2-oxazolidone in combination with at least one co- solvent and a solute.

The invention provides a new non-aqueous cell with a large 40 energy density consisting of a highly active metal anode, a Λ Λ Λ Y (t β Λ 4 manganese dioxide containing cathode and a liquid organic electrolyte consisting of 3-methyl-2-oxazolidone in combination with a conductive solute with or without at least one cosolvent having a viscosity less than that of 3-methyl-2-oxazolidone and where the manganese dioxide has a water content of less than 1% by weight based on the weight of the manganese dioxide Preferably the water content should be less than 0.5 wt% and more preferably below about 0.2 wt%.

The proprietary water, which is present in both the electrolytic and chemical types of manganese dioxide, can be largely removed by various treatments. For example, the manganese dioxide can be heated in air or in an inert atmosphere at a temperature of 350 ° C for about 8 hours or at a lower temperature for a longer period of time. Care should be taken to avoid heating the manganese dioxide above the decomposition temperature, which is about 400 ° C in air. Higher temperatures can be used in oxygen atmospheres. According to the present invention, the manganese dioxide should be heated for a sufficient period of time to ensure that the water content is reduced below about 1% by weight, preferably below about 0.5% and more preferably below about 0.2% by weight. based on the weight of manganese dioxide. An amount of water above about 1% by weight would react with the highly active metal anode, such as lithium, and cause corrosion thereof, resulting in hydrogen evolution. As mentioned above, this can result in physical collapse of the cell and / or electrolyte leakage from the cell during storage or discharge.

In order to effectively remove the unwanted water from MhOg or MhOg mixed with a conductive agent and a suitable binder, up to the level necessary to practice the present invention, it is considered necessary that both the absorbed and the bound water essentially removed. After the water removal treatment is complete, it is essential that the manganese dioxide be shielded to prevent water absorption from the atmosphere. Bit can be accomplished by treating the manganese dioxide in a drying box or the like. Also, the treated manganese dioxide, or the manganese dioxide combined with a conductive agent and an appropriate Jnztdel, can be heat treated to remove water, which may be absorbed from the atmosphere.

8003660 * »5

Preferably, the manganese dioxide should be heat treated to remove its water content below about 1% by weight and then it can be mixed with a conductive agent such as graphite, carbon or the like and a binder such as Teflon (trademark of polytetrafluoroethylene) ethylene alkyl acid polymer or the like to make a solid cathode electrode. If desired, a small amount of electrolyte can be included in the manganese dioxide mixture.

An additional possible advantage in removing nearly all of the water from manganese dioxide is that when small amounts of water are present in the electrolyte of the cell, the manganese dioxide will absorb most of that water from the electrolyte and thereby the reaction of the water with the anode, such as lithium, will be prevented or practically delayed. In this situation, the manganese dioxide will act as an extraction agent for the water impurities in the organic solvents.

The electrolyte for use in the present invention is a 3Hnethyl-2-oxazolidone based electrolyte. Liquid organic 3-methyl-2-oxazolidone material, (3Me20x) on I-i. "Ch2-ch2-o-co-it-ci5 is an excellent non-aqueous solvent due to its high dielectric constant, chemical inertness to battery components, wide liquid range and low toxicity.

However, it has been found that when metal salts are dissolved in liquid 3Me20x for the purpose of improving the conductivity of 3Me20x, the viscosity of the solution may be too high for its effective use as an electrolyte for some non-aqueous cell applications other than those, which require very low current taps. Therefore, in some applications of the present invention, the addition of a low-viscosity cosolvent will be desirable when 3Me20x is used as an electrolyte for non-aqueous cells, which can operate at or provide a high energy-55 density level .

In particular, to achieve a high energy density level according to the present invention, it is essential to use a heat treated MhO 2 cathode together with a strong one. active metal anode. Thus, the present invention is directed to a novel high energy density cell with a highly active 8003660 6 metal anode, such as lithium, a heat treated MhOg cathode and an electrolyte containing 3Me20x in combination with a conductive solute with or without at least one low viscosity co-solvent.

The low viscosity e-solvents when used in the present invention include tetrahydrofuran (THE1), dioxolan (DIOX), dimethoxyethane (DME), propylene carbonate (PC), dimethylisoxazole (DMl), diethyl carbonate (DEC), ethylene glycol sulfite (EGS), dioxane, dimethyl sulfite (DMS) or the like.

Dimethoxyethane (DUE), dioxolan (DIOX) and propylene carbonate (PC) are preferred co-solvents because of their compatibility with metal salts dissolved in liquid 3Me20x and their chemical inertness to the cellular components. In particular, the total amount of the low viscosity cosolvent added may be between about 20% and about 80% based on the total solvent volume, ie excluding solute, to lower the viscosity to a level, which is suitable for use in a cell with a large decrease.

Conductive solutes (metal salts) for use in the present invention with the liquid 3Me20x can be selected from the group MCP ^ SO ^, MBF ^, MCIO ^ and MM'Pg wherein M is lithium, sodium or potassium and M 'phosphorus, arsenic or antimony.

The addition of the solute is necessary to improve the conductivity of 3Me20x, so that the 3Me20x can be used as the electrolyte in non-aqueous cell applications. Therefore, the particular salt selected should be compatible and non-reactive with 3Me20x and the electrodes of the cell. The amount of solute to be dissolved in the liquid 3Me20x should be sufficient to provide good conductivity, that is, -4 -1 -1 30, at least about 10 µm cm. Generally, an amount of at least about 0.5 mole will suffice for most cell applications.

Highly active metal anodes suitable for the present invention include lithium (lii), potassium (k), sodium (Na), calcium (Ca), magnesium (Mg), aluminum (Al) and their alloys. Of these active metals, lithium will be preferred because, in addition to being a flexible soft metal that is easily assembled in a cell, it has the largest energy-to-weight ratio of the group of suitable anode metals.

40 The present invention of a high energy density cell 800 3 6 60 7

JMe20x-based electrolyte, a solid MhO4-containing cathode with less than 1% by weight of water and a highly active metal anode will be further illustrated in the following examples. Example I

Thermo gravimatic analyzes (TGA) were performed on various samples of commercially available manganese dioxide. Some of the samples were analyzed as obtained, other samples were heated at 350 ° G for 8 hours, and still others were heat-treated at 350 ° C for 8 hours and then mixed with 10 dye and Teflon to make cathode mixtures.

The data obtained from the thermogravimetric analyzes are shown in Table A. The data clearly shows that commercial types of manganese dioxide contain large amounts of water. In addition, the data show that even after the manganese dioxide 15 has been heat treated as specified above, the water will absorb from the atmosphere even after only a short period of time.

Example II

Each of two flat type cells was constructed using a nickel metal base with a shallow depression therein, into which "the contents of the cell were placed and over which a nickel metal cap was placed to seal the cell. The contents of each cell sample existed from a 2.5 cm diameter lithium disc consisting of five sheets of lithium foil with a total thickness of 0.25 cm, about 4 ml of an electrolyte consisting of about 40% by volume dioxolan, about 30% by volume dimethoxyethane (DME ), about 30 vol.% 3Me20x plus about 0.1% dimethylisoxazole (DMI)

and containing 1 M LiCE-SO, a porous non-woven polypropylene-P P

separator with a diameter of 2.5 cm and a thickness of 0.25 mm, which absorbed part of the electrolyte and two grams of compressed cathode mixture to form a cathode with an apparent surface area of 5 µm. In the first cell, the cathode mixture consisted of Tekkosha electrolytic MhQg treated for 20 hours at 350 ° C, carbon black, and Teflon. In the second oil, the same types of components were used as in the first oil, except that the Tekkosha MhOg was untreated. Each cell was discharged under a load of 1200 ohms at a voltage of 1 volt and the cathode performance was calculated along with the total energy densities, assuming a 1-electron reaction. 40 The data obtained are shown in Table B.

800 3 6 60 8

Example III

Ten miniature button cells were constructed using a lithium anode, an electrolyte consisting of about 40 vol.% Dioxolan, about 30 vol.% DME, about 30 vol.% 3Me20x 5 plus about 0.1% 3) 3X11 and 1 H IIIC SO 2 and a cathode containing 80 wt.% Unheated or heat treated MhOg, 1.5 wt.% Carbon black, 13 wt.% Graphite and 50 wt.% Ethyleneorylzunr binder. The heat treated 3MhO 2 was heated under an argon atmosphere for 18 hours at a temperature of 350 ° C. Each cell (diameter 11.5 mm, height 4.2 mm) contained 0.3045 g of the untreated MhOg-containing cathode mixture, or 0.3036 g of the heat-treated MhO2-containing cathode mixture, 0.037 g of lithium, a polypropylene separator and 140 µl of the electrolyte. Each cell was placed under a continuous background load of 6200 olim and pulsed once a week for two seconds at a load of 250 olm. After reaching a voltage drop of 1 volt, the cell capacity and the coulombic power of the cathode for each cell were calculated, which are listed in Table C.

8003660 9

Example 17

Two cells were constructed similar to the cells of Example II except that 1.5 ml of electrolyte was used and in the first cell the cathode mixture (porosity 33%) consisted of 5 80 wt.% Tekkosha MnOg, 10% by weight of carbon black and 10% by weight of carbon black. % Teflon, and in the second cell the cathode mixture (porosity 45%) was the same, except that the MhOg electrolytic MhOg was prepared by Ion Carbide Corporation. The MhOg in each cell was heat treated and then mixed into cathode beads, which were dried at 120 ° C under a reduced pressure. The nominal electrode separation area for 2 each electrode was 2 cm. The cells were continuously discharged under a load of 3000 ohms and the cathode coulombic power consumption at a decrease of 2.0 volts was calculated as 88% for the Tekkosha MhO4 containing cell and 99% for the other cell.

Example V

Different cells with a diameter of 11.6 mm and a height of 4 »2 mm were constructed using 0.36 g of cathode mixture, which contained 86 wt% Tekkosha MhOg, 8.5 wt% carbon black, 2.5 wt. % graphite and 3.0 wt.% Teflon, 0.03 µl lithium anode and 140 µl 20 of the electrolyte as used in Example III. The MhOg became,

- prior to the formation of the cathode mixture, at 350 DEG C. for 8 hours

treated. After that, the formed cathode mixture beads were exposed to different levels of moisture for different periods of time and then assembled into cells. The possible swelling measurements and the possible leakage, after storage for varying periods of time, are included in table H. The swelling measurement is the deviation in µm of the height of the cell from the original height of the cell due to anode corrosion and / or gas evolution within the cell. Leakage is optional electrolyte, which is visually detectable at the sealing surface of the cell.

The cells were then discharged over a 15,000 ohm load until the voltage dropped to 2.4 volts. The average milliamp hours of capacity delivered by the cells in each sample group is also included in Table H.

The data shown in Table B show that the cells in which the heat treated MhO 2 cathodes are exposed to significant moisture levels begin to swell within 24 hours. Any decrease in bloating over time may be due to some of the gas escaping through the cover / gasket / container interface when leakage occurs.

On S6 6 0 10

Example 71

Six cells were constructed in a similar manner to the first cell sample in Example 17 except that three cells (samples 1-3) used an electrolyte of 1 M liBE ^ in a 2: 3 volume% ratio of 3Me20x-DME and at the second three cells (samples 4-6) an electrolyte of 1 M was used

LiCE, S0, in a 2: 3 volume% ratio of 3Me20x-DME. The cells 33 were continuously discharged under a 3000 ohm load and at different periods of time the cells were pulsed for two seconds over a 250 ohm load. The observed voltages and the cathode coulombic power calculated at a decrease of 2.0 volts are included in Table E.

8003660 11 «a dj 0

ÜJ -H

* 1 O 2 O v- MO I I ON c- o 0 O · »·> I I 1 1 -d p m o l I m

o M

ö ^ § 0 o i> O rj

0 O

£ lC ®

0 · o ^ f "^ f" i— I t— CT \ EH

ï p in «> · 1 I ** · 1, S3 0 m ^ i- o r- I - CM + tö © j,« +5 1 Η H £ cö p o η νλ c— ισ \ vo ö

o o · 1 «· 1 I - H

N ra tn tn O O I o CM «D

S3 H +

Pt1 M f4 "{fp 0 ® +» j> oc— mm in co ii1 o cö ra in ·. · «» · »· 1 · 1 h MP CM CM O oo O CM ra 0 a £ PO 50 0 -rl 1.

φ jg H + -p 0 o r— m ^ in co v- o

r »c1 t» λ · 1 • 'O CM

© CM CM O O OO CM

f1 Λ I

0 H „« H cö 0 approx

HCÖOOCM mvo ^ 'ö -3 H

<Ö · Η -P O Λ Λ o 1 Μ Λ XU (D

- .PjOr-T-O O O O V- hI ra 3 -¾ ® CQ 0 CM & ^ £ P O 0 S I Λ M 3 **

• r: | | -P ra O I S H

• H tl φ Si ra 60 ιβ © Ml. ® fik 60 60 0 H S3 M §0 ® ® -3 's' d vo ra ooo 60 ί> M o fl 0 ® cö

0) d Μ M O 0 0 O Ή Λ CM O

• Η 0 ΐ fl 0 O 60 i> S3 S3. f ® o m Η δο 0 ca -P Μ 0 o cö 0 3 rQ, 0

& s3 60 cö ra <d o M ca t> c0 H S I

© cö S3 ® o ca O © _,!>> Siti o -p pj -p id fik ^ -p, cj m ra + »101-10 -h ca ra H 'ö tÜ ^ p S3 ca © 3 ca S3 © ran -¾ 'H ra rt o 0 P 3 OPH 0 Φ Λ · Η ti Ο Ο2 · ΗΡΐ30ΐα (ΟΡ Η 0 Η -η ra> 0 oh 0 ra © + »00 is ÖC Η Μ δΟ · 0 © 3 60 Η 01 ™ 2 «Έ © ödo-Ps3 Μ ρ -η ρ © 60« ra 0 ο δο δ £ Η ο ο ο -Η -Η ra ο rap1, rl, _ Η> Ν |> Ο0 IÖ 0 · Ο δο Ο1 Η ra -Ρ 0 -Γ-: ΜΗ MSI Η S3 Ο. CM © · Η fii δ £ -η »©, ® m ηρ-Ηγ® © η Μ Q ® °

CÖ Μ cm -Η 0 ο 0, S -® 3, I S WP

ρ, ώ Ο, 3 · Λ Μ rao HM © Si CM g 3 Ο i> S3 o ö £ 0 δθΗΐη © 0ΐ3ΛΡθ _ © £ ® © ra s ra © S3 r® ra © o 'ca 3 ca gg 60 O 0 rl 0 M 0 M 60 Ή, 3 C— M g, 30.3

M, ω ca ca m 0. «© qrapT-0 ^ ra-dcg-H

© ΜΛ -o © s3O0Ocd ft cö o o S i> ft OOÏ0O0 ^ © «Hgg ^ irafl S Ή Ώ ü S.

0 o 0 ra © p S3 © 0, MPi3M

ra ^ i raoïP Λοο MiS 0 © P ι3 ®, 3 ® Ö ö w o m ra ij P ö 0 o®i3 © ra 0 E-iMcqo o 0 Λ! m δΟ O ij © ρ si Μ <h δο ca Üi M Hl KS g & S ÏÏ ca M 60 m Pfi H 60 S £ 1 1 1 8003660 3t SS1 1 3 1 12

TABLE · B

gg

Yermogen Cathode energy

Cathode 1 electron density (Wh / in ^) heat-treated

Mn02 81.0% 72.8 unheated MhOg 48> 2% 35 »2

3E

Coulombic

Table C

Cell sample Mh02 Cell capacity Cathode (m Ah) power (.%, 1 „) 1 heat treated 37> 6 50.0 2 heat treated 30.2 40.3 3 heat treated 39.2 52.2 4 heat treated 48.0 81.4 5 heat treated 41.4 55.3 6 not heated 6.1 8.2 7 not heated 26.4 35.5 8 not heated 34.2 45.7 9 not heated 10.9 14.5 10 not heated 4 »9 8.6 8003 660 13 <d 1Λ r (M U3 CM I ON GO CD VO r- v-

g VO M3 C · - M3 M3 I CM VO ΙΛ (Λ v | - KV

* 0 & £ „

03 o OO VO O ON £ "- ON O

O CCN VO CM CM I ^ CM t ~ j- LCN

t “'vi- T · \ \ I ^ 0 Ν, \\ ιη0 I i> i> 0Nt-i> p OOUN-r- CM CM I'C'» Ö r $ CO CM Η "M3 rj oo ^ f · CM · »CM · * CM **" qJ r> · ν ·.> - · »O" ^ ON r- -r-

tö oiAvoc ~ vofavoin> fflO

a O ^ CMC-rt'tA ^ WCMtAr + I + + + + + + + + + roj a C8

H

ra fl g, g pj pj VO CM VO M3 'Φ + VO 0

3 ie TT V- ΚΝ ΙΛ ^ σ \ + CO 1Λ B

a ixnitn oo [ιλ o f- in om 0 a CM CM —CM I tn Γ- CM CM Ϋ ΙΛ 9 3 CM I + O + + I + + + + + + 2 'ks ** 0 a a_i rH ^ ö VO M3 ^ VO CM co cd

Eu: CÖ o 0 «. CM, Λ 0 Ü CÖ «O ^ -CO ^ VOv - '+ T-C'-t-?

• H a O - OCMVOOOLTVCOUNNN

_i ininrCMNvt, T-cMmvt-'Ni7 ft

Hr- O + + + + + + + + + + + gg 2 I § 0 Nö CO '^ LfN'ïi + 0 M3 «0

q m λ%% ****** * H

Ο & £ 'vl' «M'CMrCMr-CMCOCN 1¾ 0 tö -5) ·« cMomNinotnino hts 0tö [ininintcirinrtninnifl o

pj JCMCMv- + + + + + + + + BB

P H H I + I + -g 'H * 0 ^

tp) VO0CT \ + 0M-CM + 0 B

trj & d CM CO „λ ·» · »· * ·» · »·» H0

p., - j Cd »» 'tinM "C3N ONT-CMvftn 0H

B ati IVOC — UNLfNOVOC— fCNKNCOfCN

p 0 1 t ^ -CMmiAM-cMM-ininin B a> <j CÖ y ~ l + l + + + + + + + + + £ 0

CU H

** Cd H

cd cö 4 §s 55 I.

OH 5 '"j rt η B fi Cd ί> 0 B BBS 3' dB m'd

Crt 43 · Η · Η · Η · Η Ή a · Η 0 Ο, 5 © .Bppapaaa + is a o **

+3 O

(mo> b o ltn o o o m in -p -p 00 · π cMCMCMincMCMinfncM + I vf 0¾

Ö Η · Η O PP

g Λ 43 CM

^ ^ 0 0 • Η · Η

Η Η H

0 cd cd

5 c- * P -P

& r + «Μ · ν1 · ΐη (Ννονθ t-ONCM 00 • H v- KN CMt-t— T-T— CMCMCMM3C1 & fl? 0 p 5 © 0

for o -P 'B

o 00> B © ^ 0 £

© -P

© -p +> P.-P 2 2

0 0 jB <B

OB rCMIAvflftVONOJOVOrCM W

B O τ 'T- C5 a 8003660 14

TABLE E

Number of days Cathode Coulombic

Sample 15 6 8 Power (% S) 56 Voltage Readings (Volts *) 1 2.92 2.87 2.68 2.11 89 (2.31) (2.31) (2.00) (1.45) 2 2.83 2.83 2.64 2.07 87 (1.96) (2.03) (1.70) (1.31) 3 2.87 2.83 2.59 2.28 88 (1, 72) (1.86) (1.33) (1.14) 4 2.89 2.85 2.69 2.28 88 (2.12) (2.15) (1.91) (1.58 ) 5 2.88 2.82 2.64 1.92 88 (2.01) (2.06) (1.87) (1.52) 6 2.89 2.85 2.68 2.08 88 ( 2.05) (2.05) (1.81) (1.37)

Stress values in parentheses () are the pull stresses and the other stress values are the continuous stress readings observed after the given time period.

8003660

Claims (15)

A met-aqueous cell containing an active metal anode, a manganese dioxide-containing cathode and a liquid organic electrolyte, which electrolyte contains 3-methyl-2-oxazolidone in combination with a solute, and in which the manganese dioxide has a water content of less than 1% by weight based on the weight of the manganese dioxide. 2. Cell according to claim 1, characterized in that the water content is less than 0.5% by weight, based on the weight of the manganese dioxide. Cell according to claim 2, characterized in that the water content is less than 0.2% by weight, based on the weight of the manganese dioxide. Gel according to claims 1 to 5, characterized in that at least one cosolvent is present in the liquid organic electrolyte. Cell according to claim 1, characterized in that the cathode contains manganese dioxide, a conductive agent and a binder. 6. Oops according to claim 4? characterized in that the cathode contains manganese dioxide, a conductive agent and a binder. Cell according to claim 5 or 6, characterized in that the conductive agent is carbon or graphite and that the binder is polytetrafluoroethylene or ethylene acrylic acid polymer. Cell according to claim 4, characterized in that the solvent is tetrahydrofuran, dioxolan, dimethoxyethane, dimethylisoxazole, diethyl carbonate, propylene carbonate, ethylene glycol sulfite, dioxane and / or dimethyl sulfite. Cell according to claim 4, characterized in that the solute is MCi, SO, MCIO, and Fg, wherein M represents lithium, sodium or potassium and M represents phosphorus, arsenic or antimony. 10. Cell according to claim 1, characterized in that the active metal anode is lithium, potassium, sodium, calcium, magnesium, aluminum or alloys thereof. Cell according to claim 8, characterized in that the solute is MCF 2 SO 2, MC 10 2 and / or MM'lPg, wherein M represents lithium, sodium or potassium and M 'phosphorus, arsenic or antimony. 8003660 Cell according to claim 11, characterized in that the active metal anode is lithium, potassium, sodium, calcium, magnesium, aluminum or alloys thereof. 15. Cell according to claim 4, characterized in that the anode is lithium and the electrolyte LiCF 2 SO 2 is dissolved in 3-methyl-2-oxazolidone, dioxolane, dimethoxyethane and / or dimethyl isoxazole. Cell according to claim 4, characterized in that the anode is lithium and the electrolyte LiF 2 is dissolved in 3-10 methyl-2-oxazolidone and dimethoxyethane. Cell according to claim 4, characterized in that the anode is lithium and the electrolyte liCF 2 SO 2 is dissolved in 3-methyl-2-oxazolidone and dimethoxyethane. 16. A cell according to claim 4, characterized in that the anode is lithium and the electrolyte LiCF 2 SO 2 is dissolved in 3-methyl-2-oxazolidone and propylene carbonate. 8003660