Bricklike Ca9Co12O28 as an Active/InactiveComposite for Lithium-Ion Batterieswith Enhanced Rate Performances

摘要

Transition-metal oxides are considered as promising anode materials because of the high theoretical specific capacities. However, the fast capacity fading and unstable cycling performance restricted their electrochemical performance. To achieve fast and stable lithium storage capability, in this work, bricklike Ca9Co12O28 is synthesized via a modified Pechini method with the assistance of the C12H25SO4Na surfactant. The as-obtained Ca9Co12O28 ternary oxides exhibit stable structural stability, which may be attributed to the in situ formed CaO layers during the first discharge process. When tested as an anode material in lithium-ion batteries (LIBs), bricklike Ca9Co12O28 exhibits an excellent reversible capacity of 517 mA h g^–1 at 1 C after 200 cycles. Even at the high rate of 3 C, the discharge capacity can still reach 392 mA h g^–1 after 200 cycles. It reveals a great application prospect in anode materials of LIBs.