CPC H01M 4/386 (2013.01) [C01B 33/021 (2013.01); H01M 4/134 (2013.01); H01M 4/1395 (2013.01); H01M 4/366 (2013.01); H01M 10/052 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] | 8 Claims |
1. A negative electrode active material for a secondary battery, wherein the negative electrode active material comprises silicon-based primary particles,
a particle size distribution of the silicon-based primary particles is 50 nm≤D10<80 nm, 80 nm≤D50 (median particle diameter)≤100 nm, and 105 nm<D90≤150 nm,
the particle size distribution width (D90−D10)/D50 of the silicon-based primary particles is 1.0 or less,
circularity of the silicon-based primary particles is in a range of 0.6 to 0.8, wherein the circularity is defined as:
where A is a projected area of the two-dimensionally projected silicon-based primary particles, and P is a perimeter of the two-dimensionally projected silicon-based primary particles, and
wherein the silicon-based primary particles comprise a silicon particle core and a silicon oxide layer formed on the core.
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