Bricklike Ca₉Co₁₂O₂₈ as an Active/Inactive Composite for Lithium-Ion Batteries with Enhanced Rate Performances

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.