Abstract: A non-aqueous electrolyte secondary cell containing a compound of an olivinic structure as a cathode active material is to be improved in load characteristics and cell capacity. To this end, there is provided a non-aqueous electrolyte secondary cell including a cathode having a layer of a cathode active material containing a compound represented by the general formula LixFe1-yMyPO4, where M is at least one selected from the group consisting of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B and Nb, with 0.05≦x≦1.2 and 0≦y≦0.8, an anode having a layer of a cathode active material containing the anode active material and a non-aqueous electrolyte, wherein the layer of the cathode active material has a film thickness in a range from 25 to 110 &mgr;m. If a layer of a cathode active material is provided on each surface of a cathode current collector, the sum of the film thicknesses of the layers of the cathode active material ranges between 50 and 220 &mgr;m.

Abstract: A non-aqueous electrolyte cell in which the allowable range of starting material s for synthesis left in a cathode active material is prescribed in order to realize satisfactory cell characteristics. The non-aqueous electrolyte cell includes a cathode containing a cathode active material, an anode containing an anode active material, and a non-aqueous electrolyte, in which the cathode active material is mainly composed of a compound represented by the general formula LixFePO4, where 0<x≦1, with the molar ratio of Li3PO4 to a compound represented by the general formula LixFePO4 to the compound represented by the general formula LixFePO4, which ratio is represented by Li3PO4/LiFePO4, being Li3PO4/LixFePO4≦6.67×10−2.

Abstract: A cell in which liquid leakage or destruction may be prevented as the apparent energy density per unit volume of the cell is maintained. The cell uses, as a cathode active material, a compound of an olivinic crystal structure having the formula LixFe1−yMyPO4, where M is at least one selected from the group of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B and Nb and 0.05≦x≦1.2 and 0≦y≦0.8. By adjusting the amount of the electrolyte solution, the amount of the void in the container is set so as to be not less than 0.14 cc and not more than 3.3 cc per 1 Ah of the cell capacity.

Abstract: An non-aqueous electrolyte cell having superior electronic conductivity and superior cell characteristics. A cathode active material used for the cell is a composite material of a compound having the formula LixFePO4, where 0<x≦1.0, and a carbon material, wherein the specific surface area as found by the Bullnauer Emmet Teller formula is not less than 10.3 m2/g.

Abstract: A solid electrolyte cell in which cell characteristics are not deteriorated even on overdischarge to the cell voltage of 0V, such that the shape of the cell encapsulated in the laminate film is maintained. The cell includes a cathode containing a compound represented by the general formula LixFe1-yMyPO4 where 0.05≦x≦1.2, 0≦y≦0.8, and M is at least one selected from the group consisting of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B and Nb, an anode and a solid electrolyte. An electrode unit 1 comprised of the cathode and the anode layered together with interposition of the solid electrolyte is encapsulated with a laminate film 2.

Abstract: A LiFePO4 carbon composite material is to be synthesized in a single phase satisfactorily to achieve superior cell characteristics. In preparing a cathode active material, starting materials for synthesis of a compound represented by the general formula LixFePO4, where 0<x≦1, are mixed, milled and a carbon material is added to the resulting mass at an optional time point in the course of mixing, milling and sintering. Li3PO4, Fe3(PO4)2 or its hydrates Fe3(PO4)2·nH2O, where n denotes the number of hydrates, are used as the starting materials for synthesis of LixFePO4. The the temperature of a product from said sintering is set to 305° C. or less when said product from said sintering is exposed to atmosphere. The oxygen concentration in a sintering atmosphere is set to 1012 ppm in volume or less at the time point of sintering.

Abstract: A LiFePO4 carbon composite material is to be synthesized in a single phase satisfactorily to prevent the deterioration of the performance of the cathode active material from occurring and achieve superior cell characteristics. In preparing a cathode active material, starting materials for synthesis of a compound represented by the general formula LixFePO4, where 0<x≦1, are mixed, milled and a carbon material is added to the resulting mass at an optional time point in the course of mixing, milling and sintering. Li3PO4, Fe3(PO4)2 or its hydrates Fe3(PO4)2.nH2O, where n denotes the number of hydrates, are used as the starting materials for synthesis of LixFePO4. The temperature of a product from said sintering is set to 305° C. or less when said product from said sintering is exposed to atmosphere.

Abstract: A cathode active material improved in electron conductivity and a non-aqueous electrolyte cell employing this cathode active material and which is improved in cell capacity and cyclic characteristics. The cathode active material is composed of a compound having the general formula LixFePO4 where 0<x≦1.0, and a carbon material, with the carbon content per unit weight being not less than 3 wt % and with the powder density being not lower than 2.2 g/cm3.

Abstract: A LiFePO4 carbon composite material is to be synthesized in a single phase satisfactorily to achieve superior cell characteristics. In preparing a cathode active material, a starting material for synthesis of a compound represented by the general formula LixFePO4, where 0<x≦1, is mixed, milled and sintered and a carbon material is added to the resulting mass at an optional time point in the course of mixing, milling and sintering. Li3PO4, Fe3(PO4)2 or its hydrates Fe3(PO4)2.nH2O, where n denotes the number of hydrates, are used as the starting material for synthesis of LixFePO4. The particle size distribution of particles of the starting material for synthesis following the milling with the particle size not less than 3 &mgr;m is set to 2.2% or less in terms of the volumetric integration frequency.