POWDER FOR NEGATIVE ELECTRODE MATERIAL OF LITHIUM-ION RECHARGEABLE BATTERY ELECTRODE, AND METHOD OF PRODUCING SAME

摘要

Disclosed are a powder for the negative electrode material of a lithium-ion rechargeable battery having a silicon-rich layer on the surface of a low-grade silicon oxide powder, and a powder for the negative electrode material of a lithium-ion rechargeable battery comprising a silicon oxide powder. The powder for the negative electrode material of a lithium-ion rechargeable battery is characterized in that c/d <1, where c is the value of the molar ratio of oxygen to silicon on the surface of the silicon oxide powder, and d is the value of the molar ratio of the total oxygen to silicon. Preferably, c < 1 and/or 0.8 < d < 1.0. In addition, preferably: the surface of the powder does not contain crystalline silicon; the inside of the powder is amorphous; and there is a conductive carbon film on the surface. The surface of the powder for the negative electrode material of a lithium-ion rechargeable battery is coated with silicon using disproportionation of SiClx (X <4). A powder for the negative electrode material of a lithium-ion rechargeable battery, which can be used in a lithium-ion rechargeable battery having a large reversible capacity and a small irreversible capacity, and a method of producing a powder for the negative electrode material of a lithium-ion rechargeable battery can thus be provided.