Abstract: A lithium secondary battery which comprises a negative electrode, a positive electrode, and disposed therebetween a polymer electrolyte comprising an ionically conductive polymer. The polymer electrolyte has a two-layer structure composed of a positive-electrode-side layer and a negative-electrode-side layer. The polymer electrolyte on the positive-electrode side contains a nonaqueous electrolytic solution containing a lithium salt in a higher concentration than that in the polymer electrolyte on the negative-electrode side. The battery is improved in charge/discharge cycling characteristics and high-load discharge characteristics.

Abstract: A lithium secondary cell with a small decrease in discharge capacity during high-load discharge and little self-discharge. The electrolytic layers of the cell consist of positive-side and negative-side polymer electrolytic layers integrated with their respective electrodes, wherein the positive-side electrolytic layer is lower than the negative-side electrolytic layer indirect current resistance.

Abstract: A secondary battery comprising a battery main body composed of at least one battery element and an external packaging film, the battery element including an electrolyte as well as a positive electrode layer and a negative electrode layer holding the electrolyte therebetween, the external packaging film closely contacting and sealing the battery element, wherein the external packaging film sealing the battery element has, at a surface thereof, a difference in level according to a contour of the battery element.

Abstract: A lithium polymer secondary cell having a negative electrode, a positive electrode and, arranged between the electrodes, a polymer electrolyte layer, characterized in that the cell has been subjected to a heat treatment at a temperature of 40 to 60° C. after the assembly thereof. The polymer cell is freed of or is reduced in the adverse effect of a residual monomer and initiator on the performance of the cell. The polymer electrolyte is formed by cross-linking polymerization of a precursor monomer for an ion conducting polymer in a non-aqueous electrolyte, and the residual monomer and initiator contained therein is consumed by the heat treatment.

Abstract: A photovoltaic cell comprises: an anode electrode including a conductive support and a porous semiconductor layer; a photosensitive dye; a charge transport layer; and a counter electrode support, wherein the anode electrode has the property of causing cathode luminescence having a luminous peak wavelength in a visible region and shows a haze rate H of 60% or more at a wavelength in the visible region.

Abstract: A lithium secondary battery includes a positive electrode containing a first solid electrolyte; a negative electrode containing a second solid electrolyte; and a layer of a third solid electrolyte between the positive and negative electrodes.

Abstract: A polymeric solid electrolyte is composed of a polymer that contains an electrolyte salt and an organic solvent. The organic solvent is composed of a fluorinated organic solvent. The polymer solid electrolyte can retain a sufficiently high ion conductivity and provides excellent safety by exhibiting flame retardancy when heated.

Abstract: A process for producing a positive electrode active material for a nonaqueous secondary battery comprising the steps of: dissolving, in an alcohol as a medium, a starting material which contains metals necessary for giving a compound represented by the formula LiNi1−xMxO2, wherein 0≦X<0.5 and M is at least one metal selected from transition metals and 3B-, 4B- and 5B-group elements, as a positive electrode active material, and which is soluble in the alcohol; adding a sufficient amount of oxalic acid to the resulting solution to produce a precipitate slightly soluble in the alcohol: separating the slightly soluble precipitate from the solution: and calcining the precipitate to obtain the positive electrode active material.

Abstract: A process for producing a positive electrode active material for a nonaqueous secondary battery comprising the steps of: dissolving compounds capable of providing lithium ions, nickel ions and optionally ions of at least one element selected from the group consisting of transition metals,-3B-group elements, 4B-group elements and 5B-group elements in a buffer solution containing at least lithium ions, thereby to prepare a starting aqueous solution; adding an oxalic acid to the starting aqueous solution to form a precipitate of oxalates of said ions and separating the precipitate; calcining the resulting precipitate to produce LiNI1−xMxO2, wherein 0≦X<0.5 and M is at least one element selected from the group consisting of the transition metals, 3B-group elements, 4B-group elements and 5B-group elements; and re-using a residual liquid after the precipitate is separated for preparing the starting aqueous solution.

Abstract: A process for producing a positive electrode active material for a nonaqueous secondary battery comprising the steps of: dissolving, in an alcohol as a medium, a starting material which contains metals necessary for giving a compound represented by the formula LiNi1-xMxO2, wherein 0≦X<0.5 and M is at least one metal selected from transition metals and 3B-, 4B- and 5B-group elements, as a positive electrode active material, and which is soluble in the alcohol; adding a sufficient amount of oxalic acid to the resulting solution to produce a precipitate slightly soluble in the alcohol: separating the slightly soluble precipitate from the solution: and calcining the precipitate to obtain the positive electrode active material.

Abstract: A secondary battery comprising a battery main body composed of at least one battery element and an external packaging film, the battery element including an electrolyte as well as a positive electrode layer and a negative electrode layer holding the electrolyte therebetween, the external packaging film closely contacting and sealing the battery element, wherein the external packaging film sealing the battery element has, at a surface thereof, a difference in level according to a contour of the battery element.

Abstract: A solid polymer electrolyte having a high ionic conductivity and a high mechanical strength, and a preparation method therefor. The solid polymer electrolyte comprises a metal salt and a polymer blend of a fluoropolymer and a polyether comprising either or both of an ethylene oxide unit and a propylene oxide unit as a monomeric unit.

Abstract: A nonaqueous battery includes a negative electrode containing a carbon material capable of absorbing/desorbing lithium, metallic lithium or an lithium alloy, a positive electrode containing a chalcogenide and a nonaqueous ionic conductor. The nonaqueous ionic conductor contains a diether compound having ether linkages at 1- and 3-positions, 1- and 4-positions or the 2- and 3-positions of a straight-chain hydrocarbon having four carbon atoms.

Abstract: A process of preparing a positive electrode active material for a nonaqueous secondary battery, comprising: making a buffered aqueous solution of a water-soluble lithium compound and a water-soluble nickel compound having a definite pH, reacting with oxalic acid and a water-soluble lithium compound and a water-soluble nickel compound to yield a co-precipitate of a slightly water-soluble salt of lithium and nickel in the resulting aqueous solution, followed by calcination.

Abstract: A nonaqueous secondary battery includes a working electrode containing graphite particles coated with less crystallized carbon and a nonaqueous electrolyte, which contains at least ethylene carbonate and propylene carbonate.

Abstract: A nonaqueous secondary cell comprises at least one pair of electrodes, and a separator provided between the at least one paired electrodes and impregnated with a nonaqueous electrolyte containing a mixed solvent of propylene carbonate and ethylene carbonate. At least one electrode of the at least one paired electrodes has, at least on surfaces thereof, an active substance layer made of composite carbon particles, which individually comprise a core of crystalline carbon and a low crystallinity or amorphous carbon layer formed on at least a part of the surfaces of the core, and a carbon matrix covering at least a part of the composite carbon particles and uniformly dispersing and holding the composite carbon particles therein.

Abstract: A process of preparing lithium nickel oxide as a positive electrode active material comprising: dissolving a water-soluble lithium compound and a water-soluble nickel compound in water to prepare a homogeneous aqueous solution; co-precipitating, from the aqueous solution, a lithium salt and a nickel salt which are slightly soluble in water; isolating the resulting co-precipitate and calcining the co-precipitate to obtain lithium nickel oxide.

Abstract: A process for preparing lithium nickeloxide (LiNiO.sub.2) for use as a positive electrode active material for a nonaqueous secondary battery, which comprises the steps of: (a) using as the raw materials a lithium compound and a nickel compound at least one of which has a melting point not higher than 300.degree. C.; i) in case where both of the lithium compound and the nickel compound have a melting point not higher than 300.degree. C., mixing the above two compounds after their melting, or mixing the above compounds, melting the mixture and mixing the melted mixture; ii) in case where either one of the lithium compound and the nickel compound has a melting point higher than 300.degree. C., mixing said one having a melting point higher than 300.degree. C. with the remaining one before or after its melting; (b)calcining the resulting mixture at a temperature of 700.degree. C. to 950.degree. C. in air or in an atmosphere containing oxygen in a higher concentration than an atmospheric oxygen concentration.

Abstract: A nonaqueous secondary battery comprising a negative electrode, a positive electrode in which a chalcogenated substance containing lithium is used as a positive electrode active material and a nonaqueous ion conductor, said negative electrode containing a negative electrode active material which is a carbon material where an amorphous carbon is adhered on the surface of graphite particles which are subjected to an oxidizing treatment.

Abstract: A lithium nickel copper composite oxide having the compositional formula Li.sub.2 Ni.sub.1-X Cu.sub.X O.sub.2 (0.0<X<1.0), which has a novel structure and enables the formation of a novel positive electrode active material having larger capacity than conventional ones, and further a secondary battery having large capacity by combining this novel positive electrode active material and a negative electrode active material made from a carbon material or the like.