| 摘要 |
A lithium ion secondary battery (100A) is provided with: a positive electrode current collector (221A), and a positive electrode active material layer (223A) which is held by the positive electrode current collector (221A). The positive electrode active material layer (223A) includes positive electrode active material particles, a conductive material, and a binder. The positive electrode active material particles (610A) comprise: a shell part (612) which is formed by primary particles (800) of a lithium transition metal oxide in the form of a layer; a hollow part (614) formed inside the shell part (612); and a through-hole (616) which passes through the shell part (612). In addition, the major diameter of the primary particles (800) of the lithium transition metal oxide is 0.8 mum or less, on average in the positive electrode active material layer (223A). |
