Negative electrode active material for nonaqueous electrolyte secondary batteries
AssigneeMitsui Mining & Smelting Co., Ltd.
InventorsDaisuke Inoue, Yanko Marinov Todorov, Shinya Kagei
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Abstract
Proposed is a novel negative electrode for nonaqueous electrolyte secondary batteries in which the battery capacity does not decrease even when charging and discharging are repeated. Proposed is a silicon-containing negative electrode active material for nonaqueous electrolyte secondary batteries, comprising negative electrode active material particles which are provided with a surface layer containing carbon and titanium or aluminum on the entirety or a portion of the surface of the active material.
Claims22
A silicon-containing negative electrode active material for nonaqueous electrolyte secondary batteries, wherein the negative electrode active material particles comprise a surface layer comprising carbon and titanium or aluminum on an entirety or a portion of a surface of a core portion,
- wherein the core portion comprises:
- pure silicon;
- a silicon alloy selected from SiB4 or SiB6, Cu5Si, FeSi2, or Mg2Si;
- or a silicon compound selected from Si3N4 or SiC in an amount of 90% by mass or more, and
- a content of titanium or aluminum in the surface layer is 0.002 to 0.07% by mass of the silicon-containing negative electrode active material particles.
Dependencies are inferred from the claim text.