ACTIVE SUBSTANCE FOR NEGATIVE ELECTRODE AND NEGATIVE ELECTRODE AND LITHIUM ION SECONDARY BATTERY USING THE SUBSTANCE

摘要

In a negative electrode active material for a lithium ion secondary battery including a silicon oxide capable of absorbing and desorbing lithium ions, a silicon oxide having structural units each in the form of a tetrahedron in which a silicon atom is located at its center and silicon or oxygen atoms are located at its four vertices is used. The structural units are arranged randomly to form an amorphous structure. In the case that the number of oxygen atoms located at the four vertices in the structural units is represented by n (n = 0, 1, 2, 3 or 4) and the structural units are represented by Si(n), the number of the structural units NSi(n) in the silicon oxide satisfies the following relations (1) to (3). Formula 1 NSi 0 ˆ‘ NSi n ‰¥ 0.1 NSi 4 ˆ‘ NSi n ‰ 0.1 NSi 1 + NSi 2 + NSi 3 ‰  0