Abstract: The present invention provides a non-aqueous electrolyte solution comprising a non-aqueous solvent and a lithium electrolyte, wherein the non-aqueous solvent is obtained by adding a phosphoric acid compound prepared by substituting at least one hydrogen atom in phosphoric acid or polyphosphoric acid with a group represented by the general formula [1]: wherein, X represents Si, Ge or Sn atom, and each of R1 to R3 independently represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms.

Abstract: A polymer electrolyte comprising a sulfonated polyethersulfone having an ion-exchange group equivalent weight of 870 to 5000 g/mol, which is obtainable by sulfonating a polyethersulfone having the structural unit represented by the following structural formula, ##STR1## The polymer electrolyte is cheap, easily mold-processable by virtue of soluble property in organic solvent and thermoplastic property, easily film-processable, highly water-resistant, and suitable for a fuel cell.

Abstract: Provided is a polymer electrolyte which is cheap and easily synthesized, and has a high water resistance and high output performance.

Abstract: A non-aqueous electrolyte lithium secondary battery, comprising a cathode containing, as active material, a material that can be doped/undoped with lithium ions, an anode containing, as active material, a carbonaceous material that can be doped/undoped with lithium ions, a separator interposed between the cathode and anode and an electrolyte prepared by dissolving lithium salt in an organic solvent, wherein the anode contains a polymer having carbonate groups represented by the structural formula ?I!: ##STR1## said polymer having a number average molecular weight of not less than 300 and not more than 200,000. The lithium secondary battery has cycle life and high-rate capacity which are improved without reducing low-temperature capacity.

Abstract: The present invention provides a non-aqueous electrolyte that includes a non-aqueous solvent and a lithium salt. The non-aqueous electrolyte contains a halogen-substituted ether compound represented by the general formula (I):R.sub.1 --O--R.sub.2 (I)wherein R.sub.1 is an alkyl or halogen-substituted alkyl group having 2 or less carbon atoms and R.sub.2 is a halogen-substituted alkyl group having 2 to 10 carbon atoms. Additionally, the non-aqueous electrolyte contains at least one compound that is capable of dissolving the lithium salt in an amount of not less than 0.5 mol/liter. When this compound is added to the halogen-substituted ether compound, a mixed solvent is formed that is used as the non-aqueous solvent. The present invention also provides a lithium secondary battery that comprises a cathode that can be doped/undoped with lithium ions, an anode of a lithium metal or alloy or an anode that can be doped/undoped with lithium ions, and the non-aqueous electrolyte described above.

Abstract: A lithium secondary battery that includes a cathode containing, as an active material, a material that can be doped/undoped with lithium ions; an anode containing, as an active material, a lithium metal, a lithium alloy or a material that can be doped/undoped with lithium ions; and a liquid or solid electrolyte. In this lithium secondary battery, the active material used in the cathode is lithiated nickel dioxide containing gallium. As a result, the lithium secondary battery attains excellent cycle and overcharge resistance characteristics and has a high energy density.