| 摘要 |
PROBLEM TO BE SOLVED: To provide: a negative electrode active material for a lithium ion secondary battery superior in cycle characteristics while keeping an initial high efficiency and a high efficiency during cycle, and a high battery capacity; and a method for manufacturing such a lithium ion secondary battery negative electrode active material.SOLUTION: A negative electrode active material for a lithium ion secondary battery comprises: a Si compound; and a carbonaceous substance or a combination of a carbonaceous substance and graphite. In the negative electrode active material, the Si compound has an average particle diameter of 0.01-5 μm, and the carbonaceous substance is compounded with a complex oxide of lithium and at least one element selected from a group consisting of a transition metal, and an element of Group XIII or XV of the periodic table. The negative electrode active material is produced by: the step of mixing the Si compound, a carbon precursor, and the complex oxide of lithium and at least one element selected from a group consisting of a transition metal, and an element of Group XIII or XV of the periodic table and as required, graphite powder; granulating and compacting steps; the step of pulverizing the resultant mixture, thereby forming composite particles; and the step of baking the composite particles in an inert gas atmosphere.SELECTED DRAWING: Figure 1 |
