Production process for composite oxide, positive-electrode active material for lithium-ion secondary battery and lithium-ion secondary battery

摘要

A production process for composite oxide expressed by a compositional formula: LiMn1-xAxO2, where “A” is one or more kinds of metallic elements other than Mn; and 0≦“x”<1, obtained by preparing a raw-material mixture by mixing a metallic-compound raw material and a molten-salt raw material with each other, the metallic-compound raw material at least including an Mn-containing nitrate that includes one or more kinds of metallic elements in which Mn is essential, the molten-salt raw material including lithium hydroxide and lithium nitrate, and exhibiting a proportion of the lithium nitrate with respect to the lithium hydroxide (Lithium Nitrate/Lithium Hydroxide) that falls in a range of from 1 or more to 3 or less by molar ratio; reacting the raw-material mixture at 500° C. or less by melting it; and recovering the composite oxide being generated from the raw-material mixture that has undergone the reaction.

主权项

1. A production process for composite oxide being characterized in that:
it is a production process for composite oxide being expressed by a compositional formula: LiMn1-xAxO2, where “A” is one or more kinds of metallic elements other than Mn; 0≦“x”<1; and an averaged oxidation number of Mn falls in a range of from 2.8 to 3.2; said composite oxide is obtained via the following: a raw-material mixture preparation step of preparing a raw-material mixture by mixing a metallic-compound raw material and a molten-salt raw material with each other, the metallic-compound raw material at least including an Mn-containing nitrate that includes one or more kinds of metallic elements in which Mn is essential, the molten-salt raw material including lithium hydroxide and lithium nitrate, and exhibiting a proportion of the lithium nitrate with respect to the lithium hydroxide, Lithium Nitrate/Lithium Hydroxide, that falls in a range of from 1.2 to 3 by molar ratio; a molten reaction step of reacting said raw-material mixture at 500° C. or less by melting it; and a recovery step of recovering said composite oxide being generated from said raw-material mixture that has undergone the reaction, wherein the molten-salt raw material does not include lithium peroxide; and said composite oxide has a crystal structure belonging to an orthorhombic-system space group.