Formation of solid‐solution CoxNi1−xCO3 as high‐performance anode materials for lithium‐ion batteries.

Summary: 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. [ABSTRACT FROM AUTHOR]