Varta Batterie Aktiengesellschaft

Hans-Walter Praas

Rudolf Herr

Hermann Schomann

Sibylle Kemmler-Sack

Peter Bauerlein

Peter Endres

Johanna Oberhauser

Suitable as active cathode material for an electrochemical lithium secondary cell are oxygen-deficient spinels Li,Mn,O,, where 0&lE;x&lE;0.33 and 0.01&lE;&dgr;&lE;0.5. Their region of existence in a phase diagram laid out between the corner points MnO, MnO,and Li,MnO,for lithium manganese oxide compounds is defined by the corner compounds LiMn,O,, Li,Mn,O,, Li,Mn,O,and Li,Mn,O,, all the compounds along the lines LiMn,O,&mdash;Li,Mn,O,and LiMn,O,&mdash;Li,Mn,O,being excepted. The spinels are produced by a modified ceramic process from a mixture of Li-containing and Mn-containing starting substances whose reaction product is reduced by roasting in an Ar/H,atmosphere. The Li components x can be replaced partially or completely by foreign monovalent or multivalent cations from the series consisting of Co, Mg, Zn, Ni, Ca, Bi, Ti, V, Rh or Cu.

Electrochemical lithium secondary element

The invention relates to a laminated lithium-ion cell which comprises flexible layers, wherein the negative electrode is lithium metal, lithium alloy or a metallic bonded fiber web or a foam, which comprises a lithium-intercalating material such as carbon, graphite, tungsten dioxide, molybdenum dioxide, titanium dioxide, titanium disulfide or vanadium pentoxide as the active component, the separator is made of a porous polymer in which a non-aqueous electrolyte is immobilized, and the positive electrode as the active material comprises lithiated manganese dioxide, manganese spinel, lithium-metal oxides, lithium-metal mixed oxides or lithium-metal sulfides.

Laminated lithium-ion cell and process for fabricating same

Nontoxic, chemically stable lithium tris(fluorosulphonyl)methanide, LiC(SO.sub.2 F).sub.3, is used as a conducting salt for rechargeable lithium cells containing nonaqueous electrolytes based on esters or polymeric electrolytes such as polyethylene oxide. The cell electrolyte is preferably comprised of an approximately 1 molar solution of the salt in a mixture of 50% by volume of ethylene carbonate (EC) and 50% by volume of diethyl carbonate (DEC).

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Kelkeim, Germany

Hans-Walter Praas