Patent ID: 11557761

Abstract:
Provided is a lithium ion secondary battery including Li4Ti5O12 particles in a negative electrode active material layer and having both high heat generation suppressing performance during overcharging, and high storage stability in a high SOC region. The lithium ion secondary battery herein disclosed includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The positive electrode has a positive electrode active material layer. The positive electrode active material layer includes Li3PO4 as a secondary material. The negative electrode has a negative electrode active material layer. The negative electrode active material layer includes Li4Ti5O12 as a secondary material. The Li3PO4 content in the positive electrode active material layer is 0.5 mass % or more and 5.0 mass % or less. The Li4Ti5O12 content in the negative electrode active material layer is 0.5 mass % or more and 5.0 mass % or less.