| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery excellent in charging/ discharging with less reduction in capacity or charging/discharging efficiency even when using an electrolyte containing a propylene carbonate. SOLUTION: This lithium ion secondary battery includes a negative electrode including a negative electrode active material containing a boric acid compound, a positive electrode containing lithium transfer metal oxide enabling a lithium to go in and out, and a separator between the positive and negative electrodes. The lithium ion secondary battery also includes an electrolyte that is infiltrated into the positive and negative electrodes and the separator and contains the lithium salt, 51 wt.% or more of cyclic carbonate as an organic solvent and a chain carbonate. |
