Formation of solid‐solution Co x Ni 1− x CO 3 as high‐performance anode materials for lithium‐ion batteries

Transition metal carbonates (TMCs) as high-performance anode materials for lithium-ion batteries (LIBs) have attracted intensive research interests in recent years. Nanostructures with abundant pore channels can well address the volume change during the Li+ insertion/desertion process and shorten the ionic diffusion length. Multi-component carbonates with excellent porous structures exhibit enhanced electrochemical performance in contrast to the mono-component carbonates due to the synergistic effect among multi-metal elements. Herein, we used a simple solvothermal method to synthesize Co-based solid-solution carbonates CoxNi1−xCO3 to obtain different microstructures by changing the content of the precipitant. The optimized solid-solution Co2/3Ni1/3CO3 (CNCO-20) delivers a high initial Coulombic efficiency of 83%, a reversible high-rate capacity of 828.1 mAh g−1 at 2.0 A g−1, and good electrochemical stability with a reversible capacity of 740.9 mAh g−1 after 500 charge-discharge cycles at 1.0 A g−1 due to the enhanced electronic/ionic transport, sufficient electroactive sites, and improved electrochemical stabilities. Considering the excellent specific capacity and long life-span, the synthesized solid-solution CNCO-20 demonstrate great promise as an alternative anode electrode material compared to conventional materials for LIBs.