Toda Kogyo Corporation

Kouta Sano

Hideaki Sadamura

Osamu Sasaki

Manabu Yamamoto

Daisuke Nishikawa

The present invention provides positive electrode active substance particles which are improved in charge/discharge capacities, cycle characteristics and thermal stability. The positive electrode active substance particles according to the present invention comprise a compound having at least a crystal system belonging to a space group of R-3m and a crystal system belonging to a space group of C2/m and having a specific peak intensity ratio, in which a content of Mn in the compound is controlled such that a molar ratio of Mn/(Ni+Co+Mn) therein is not less than 0.55; a content of boron in the compound is 0.01 to 1% by weight; a content of fluorine in the compound is 0.01 to 5% by weight; and a content of an element A (at least one element selected from the group consisting of Al, Mg, Ti, Zr, Ca, Fe, Zn, Mo and Bi) in the compound is 0.004 to 9% by weight, and can be produced by calcining a mixture comprising precursor particles comprising Mn and Ni and/or Co, a lithium compound, a boron compound, a fluorine compound and a compound of the element A.

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Fukuoka-ken, Japan

Kouta Sano