| 摘要 |
Disclosed is a lithium ion secondary battery which can exhibit excellent output properties and excellent cycle properties at the same time. The lithium ion secondary battery comprises a positive electrode, a negative electrode, and a non-aqueous electrolytic solution. The positive electrode contains, as a positive electrode active material, a compound represented by general formula (I): LixNiaCobMncM'dM"eO2. In the formula, M' represents at least one element selected from Zr, Nb and Al. In the formula, M" represents at least one element selected from W and Mo. The secondary battery is additionally characterized in that the amount of M" eluted per g of a filtrate is 0.025 mmol or less as measured by inductively coupled plasma mass spectrometry wherein the filtrate is produced by agitating 2 g of a powder of the positive electrode active material together with 100 g of pure water to prepare a suspension and filtrating the suspension. |
