Negative electrode for lithium ion secondary battery and lithium ion secondary battery

Abstract

Disclosed is a negative electrode for a lithium ion secondary battery, the negative electrode including a negative electrode current collector with protrusions formed on a surface thereon, and columnar bodies being carried on the protrusions and comprising an alloy active material capable of absorbing and releasing lithium ions. The columnar bodies each have a multilayer structure in which a plurality of unit layers comprising the alloy active material are stacked sequentially on the surface of the protrusion, and the average layer thickness of the unit layer in a region within 20% of the thickness of the columnar body extending from the surface of the protrusion is smaller than that in a region within 80% of the thickness of the columnar body extending from the top of the columnar body.

Dependencies are inferred from the claim text.