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US 12,755,965 B2Granted
Method for manufacturing negative electrode active material
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsMasanori Harata, Kazuhiro Niimura, Kota Urabe, Yasuhiro Yamaguchi, Tatsuya Eguchi, Mitsutoshi Otaki, Jun Yoshida
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Abstract
A method for manufacturing a negative electrode active material includes: an alloying step of causing an Na source and an Si source to react to produce an Na—Si alloy containing Na and Si; and a silicon clathrate production step of heating the Na—Si alloy and reducing an amount of Na in the Na—Si alloy to produce a type-II silicon clathrate. Porous Si with a BET specific surface area of 20 m2/g or more is used as the Si source.
Claims6
A method for manufacturing a negative electrode active material, the method comprising:
- an alloying step of causing an Na source and an Si source to react to produce an Na—Si alloy containing Na and Si, wherein porous Si with a BET specific surface area of 20 m2/g or more is used as the Si source;
- and
- a silicon clathrate production step of heating the Na—Si alloy and reducing an amount of Na in the Na—Si alloy to produce a type-II silicon clathrate,
- wherein, in the entire silicon clathrate production step, a reaction raw material containing the Na—Si alloy and an Na trapping agent that are in contact with each other is heated, and Na derived from the Na—Si alloy is caused to react with the Na trapping agent to reduce the amount of Na in the Na—Si alloy,
- wherein a composition of Na and Si in the Na—Si alloy of the raw reaction material is represented by NaySi136, where 24<y, and
- wherein the Na trapping agent is selected from CaCl2), CaBr2, CaI2, and MgCl2.
3 more elements
Dependencies are inferred from the claim text.