CPC H01M 4/362 (2013.01) [H01M 4/38 (2013.01); H01M 4/5825 (2013.01); H01M 10/0525 (2013.01); H01M 2004/027 (2013.01)] | 12 Claims |
1. A negative electrode active material for non-aqueous electrolyte secondary batteries, comprising:
lithium silicate composite particles including a lithium silicate phase and silicon particles dispersed in the lithium silicate phase,
the lithium silicate phase being an oxide phase including Li, Si, O, and M, where
M is an element other than the following elements: Group 1 elements of alkali metals, Group 16 elements of oxygen group, Group 18 elements of rare gas, and Si, wherein
an amount of each element relative to a total amount of Li, Si and M in the lithium silicate phase is 3 mol % to 55 mol % for Li, 25 mol % or more for Si, and 3 mol % to 50 mol % for M;
a carbon material is present inside the lithium silicate composite particles;
an area ratio of the carbon material measured within an entire area excluding a peripheral region of 1 μm thick from a peripheral edge of a cross section of the lithium silicate composite particles is 0.008% to 6%, wherein the area ratio is an average of measurements of ten lithium silicate composite particles having a maximum diameter of 5 μm or more included in a cross-sectional image of an active material mixture layer containing the negative electrode active material;
the lithium silicate composite particles include an aggregate of a plurality of primary particles, the primary particles including the lithium silicate phase and the silicon particles;
the aggregate comprises a sintered body of the primary particles defining a linear continuous interface between said primary particles; and
the carbon material is present at at least part of the interface between the primary particles adjacent to each other, inside the lithium silicate composite particles.
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