LITHIUM ION SECONDARY BATTERY

摘要

One purpose of the present invention is to provide a lithium ion secondary battery which has improved input and output characteristics (especially improved output characteristics at low temperatures) without using an external device. This lithium ion secondary battery comprises a positive electrode, a negative electrode and a nonaqueous electrolyte solution. The positive electrode contains a lithium-containing olivine-type compound as a main component of a positive electrode active material, and additionally contains 2-20 parts by mass of activated carbon per 100 parts by mass of the positive electrode active material.