Patent ID: 6911282

Claim:
A non-aqueous electrolyte secondary battery comprising negative electrode containing: a negative electrode material composed of a composite particle having a core particle and a coating layer covering at least a part of surface of said core particle and capable of absorbing and desorbing lithium; and a conductive material composed of a graphite particle, characterized in that (a) a solid phase A constituting said core particle is composed of at least one element selected from the group consisting of silicon and tin, (b) a solid phase B constituting said coating layer is composed of a solid solution or an intermetallic compound, which comprises an element constituting said solid phase A and at least one element selected from the group consisting of elements of the second to the fourteenth Groups except silicon, tin, and carbon, and (c) the ratio of the median diameter “Dc” of said conductive material to the median diameter “Da” of said negative electrode material (Dc/Da) is from 0.02 to 0.5.