JP2004319469A5 - - Google Patents

Claims (9)

A negative electrode active material for a non-aqueous electrolyte secondary battery capable of inserting and extracting lithium,
Si, and at least one inner layer composed of a surface layer of silicon oxide fluorinated Ranaru average thickness 0.2~1000nm formed on the inner layer is selected from the alloys by Li Cheng group including Si And a negative electrode active material for a non-aqueous electrolyte secondary battery.   The negative electrode active material for a nonaqueous electrolyte secondary battery according to claim 1, wherein the surface layer has an average thickness of 1 to 100 nm.   The negative electrode active material for a nonaqueous electrolyte secondary battery according to claim 1, wherein the average thickness of the surface layer is 1 to 10 nm.   The negative electrode active material for a nonaqueous electrolyte secondary battery according to any one of claims 1 to 3, wherein the thickness of the surface layer is within a range of ± 50% of the average thickness. The alloy is, S i and, Ti, Co, Ni, Cu , Mg, Zr, V, Mo, W, and at least one element selected from the group consisting of Mn and Fe, of claim 1, wherein consisting Negative electrode active material for non-aqueous electrolyte secondary battery. The alloy includes at least a Si phase , Si , and at least one element selected from the group consisting of Ti, Co, Ni, Cu, Mg, Zr, V, Mo, W, Mn, and Fe. When negative active material for a nonaqueous electrolyte secondary battery according to claim 1, wherein consisting.   It is a thin film form or a powder form, The negative electrode active material for nonaqueous electrolyte secondary batteries in any one of Claims 1-6.   The negative electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, comprising an amorphous Si phase.   A nonaqueous electrolyte secondary battery using the negative electrode active material according to claim 1.