NEGATIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM ION SECONDARY BATTERIES, NEGATIVE ELECTRODE FOR LITHIUM ION SECONDARY BATTERIES, AND LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a negative electrode active material for lithium ion secondary batteries, a negative electrode for lithium ion secondary batteries, and a lithium ion secondary battery which enable the enhancement of cycle characteristics while keeping an initial capacity.SOLUTION: A negative electrode active material for lithium ion secondary batteries comprises: a Si-polymer solid electrolyte complex having Si nanoparticles and a polymer solid electrolytic layer covering at least a part of the surface of each Si nanoparticle and having a lithium ion-conductivity. The polymer solid electrolytic layer includes an organic polymer and a lithium salt.