Sharp Kabushiki Kaisha Corporation

Tanaka Chemical Corporation

Shigeyuki Hamano

Takehito Mitate

Naoto Torata

Toyoshi Iida

Tetsushi Makino

Kazuaki Minato

Tomohiko Inada

Naoyoshi Kameda

Tetsuya Yoneda

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 LiNi M O , wherein 0&lE;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.

Process for producing a positive electrode active material for a nonaqueous secondary battery and a nonaqueous secondary battery using the active material

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.

Process of producing lithium nickel oxide and nonaqueous secondary

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.

Process for preparing positive electrode active material, and nonaqueous

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Fukui, Japan

Shigeyuki Hamano