| abstract |
A lithium ion secondary battery and a method for manufacturing the same are provided. A lithium ion secondary battery includes a positive electrode including a positive electrode active material composite formed by combining a lithium silicate material and a carbon material, a negative electrode including a negative electrode active material having silicon, and an electrolyte. . When the irreversible capacity of the positive electrode is A and the irreversible capacity of the negative electrode is B, the relationship is 0.8 <B / A <1.2. [Selection] Figure 1 |