Toda Kogyo Corporation

Daisuke Nishikawa

Hideaki Sadamura

Osamu Sasaki

Manabu Yamamoto

Teruaki Santoki

Kazutoshi Ishizaki

Kazuhiko Kikuya

Kouta Sano

Taisei Inoue

Kouta Sato

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.

Positive electrode active substance particles and process for producing the same, and non-aqueous electrolyte secondary battery

The present invention relates to positive electrode active substance particles comprising 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, the positive electrode active substance particles having a specific intensity ratio; a content of Mn in the positive electrode active substance particles being controlled such that a molar ratio of Mn/(Ni+Co+Mn) therein is not less than 0.55; and the positive electrode active substance particles comprising an element A (that is at least one element selected from the group consisting of Si, Zr and Y) in an amount of 0.03 to 5% by weight and having a tap density of 0.8 to 2.4 g/cc and a compressed density of 2.0 to 3.1 g/cc. The positive electrode active substance particles can be produced by calcining a mixture of precursor particles comprising the element A, Mn, Ni and/or Co, and a lithium compound.

Positive electrode active substance particles including a compound having at least a crystal system belonging to a space group of R&#x2212;3m and a crystal system belonging to a space group of C2/m, and boron. The compound is a composite oxide comprising at least Li, Mn, and Co and/or Ni; a relative intensity ratio [(a)/(b)] of a maximum diffraction peak intensity (a) observed at 2&#x3b8;=20.8&#xb1;1&#xb0; in a powder X-ray diffraction pattern of the positive electrode active substance as measured using a Cu-Ku ray to a maximum diffraction peak intensity (b) observed at 2&#x3b8;=18.6&#xb1;1&#xb0; in the powder X-ray diffraction pattern, is 0.02 to 0.5; a content of Mn in the positive electrode active substance particles such that a molar ratio of Mn/(Ni+Co+Mn) is not less than 0.55; and the positive electrode active substance particles include boron in an amount of 0.001 to 3% by weight.

Growing community of inventors

Yamaguchi-ken, Japan

Daisuke Nishikawa