| abstract |
Disclosed are active material particles, which have properties suitable for increasing the output of a lithium secondary battery, and which are suppressed in deterioration due to charge and discharge cycles. Specifically disclosed are active material particles, each of which has a hollow structure that comprises a secondary particle wherein a plurality of primary particles of a lithium transition metal oxide aggregate and a hollow portion that is formed within the secondary particle. The secondary particle is provided with a through hole that penetrates therethrough from the outer portion to the hollow portion. The active material particles have a BET specific surface area of 0.5-1.9 m 2 /g. |