Lithium secondary battery

摘要

In a lithium secondary battery using negative electrode active material particles containing silicon, excellent charge-discharge characteristics are achieved and swelling of the negative electrode is minimized. A lithium secondary battery has a positive electrode containing a positive electrode active material, a negative electrode containing an active material layer and a current collector made of a conductive metal foil, and a non-aqueous electrolyte. The active material layer has a binder and active material particles containing silicon, and is formed by sintering the active material layer on a current collector surface in a non-oxidizing atmosphere. The active material particles have an average particle size of from 7.5-15 mum and a particle size distribution such that 60 volume % or more of the active material particles falls within the ±40% range of the average particle size, and the lithium secondary battery has a negative/positive electrode capacity ratio of 1.7 or greater.