Precipitant-free solvothermal construction of spindle-like CoCO3/reduced graphene oxide hybrid anode toward high-performance lithium-ion batteries.

Recently, CoCO₃ has attracted enormous attention as anodes for lithium-ion batteries (LIBs), benefiting from its high theoretical capacity and simple synthesis. However, the modest electronic conductivity and structural instability over cycling hinder its wider applications. To well address the intrinsic issues, we explored a precipitant-free hydrothermal methodology for mass production of spindle-like CoCO₃/reduced graphene oxide (S-CoCO₃/rGO) toward advanced LIBs as a hybrid anode. The dimethylformamide plays a significant role of "two birds (i.e., solvent and precipitant) with one stone" in the formation of the S-CoCO₃/rGO, greatly improving its practical applicability. The purposeful introduction of rGO nanosheets as a two-dimensional flexible conductive network enhances the conductivity and stability of the S-CoCO₃. It is the structural and compositional merits for LIBs that endow the S-CoCO₃/rGO with remarkable lithium-storage performance in terms of enhanced interfacial storage capacity, high-rate reversible capacities (803 mAh·g⁻¹ at 2.0 A·g⁻¹) and long-duration capacity retention of 82.1% over 2000 consecutive cycles at 2.0 A·g⁻¹. More significantly, the simple yet efficient avenue here promises enormous commercial prospect of the S-CoCO₃/rGO in next-generation LIBs. [ABSTRACT FROM AUTHOR]