| CPC H01M 4/386 (2013.01) [C01B 33/021 (2013.01); H01B 1/04 (2013.01); H01M 4/134 (2013.01); H01M 4/1395 (2013.01); H01M 4/366 (2013.01); H01M 10/0525 (2013.01); H01M 10/44 (2013.01); C01P 2002/74 (2013.01)] | 4 Claims |

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1. A method for producing an active material, the method comprising:
a preparing step of preparing an intermediate including a silicon clathrate II type crystal phase,
an alloying step of obtaining an alloy compound by alloying the intermediate and a Li based material so as a molar ratio (Li/Si) of Li included in the Li based material to Si included in the intermediate is 3 or less, and
a Li removing step of removing the Li from the alloy compound and forming a void inside a primary particle,
wherein the Li/Si is 0.5 or more.
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