摘要 |
Disclosed is a lithium ion secondary battery including: a positive electrode including a positive electrode active material layer comprising a positive electrode active material capable of absorbing and releasing lithium ions, and a positive electrode current collector; a negative electrode including a negative electrode active material layer comprising an alloy-formable active material, and a negative electrode current collector; a separator interposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte. The positive electrode active material layer has an easily swellable resin having a degree of swelling with the non-aqueous electrolyte of 20% or more, and the negative electrode active material layer has a hardly swellable resin having a degree of swelling with the non-aqueous electrolyte of less than 20%. |