| abstract |
Provided is an active material particle that exhibits performance suitable for increasing the output of a lithium secondary battery and that is less deteriorated by a charge / discharge cycle. An active material particle provided by the present invention has a hollow structure having a secondary particle in which a plurality of primary particles of a lithium transition metal oxide are aggregated and a hollow portion formed inside the secondary particle. A through hole penetrating from the outside to the hollow portion is formed in the secondary particle. The active material particles have a BET specific surface area of 0.5 to 1.9 m 2 / g. [Selection] Figure 6 |