In situ anchoring in carbon matrix of Bi2O2CO3 as a high-performance anode material for Li-ion batteries

Bismuth-based anode materials have been regarded as promising Li-ion batteries due to their high theoretical capacity. However, their low conductivity and associated volume expansion inhabited their commercialization. In this work, Bi2O2CO3@C composites were successfully synthesized by in situ anchoring of flower-like Bi2O2CO3 nanosheets on a carbon-based substrate via hydrothermal. The unique composited structure of Bi2O2CO3@C leads to a stable specific capacity of 547 mAh·g−1 after 100 cycles at a current density of 0.1 A·g−1. Notably, it demonstrates excellent rate capability with a specific capacity of 210 mAh·g−1 at 5 A·g−1. After 550 cycles at a current density of 0.5 A·g−1, a high reversible capacity of nearly 400 mAh·g−1 was observed. Additionally, in situ X-ray diffraction measurements clearly demonstrate the conversion between Bi and Li3Bi during alloying/dealloying, confirming the good electrochemical reversibility of the materials for Li storage. The reaction kinetics of Bi2O2CO3@C were further investigated using galvanostatic intermittent titration technique. Furthermore, Bi2O2CO3@C exhibited excellent long-term stability, maintaining its high reversible capacity for over 200 cycles at a current density of 0.5 A·g−1 in a full cell configuration using Li1.20Mn0.54Ni0.13Co0.13O2 as the cathode material. This result further underscores its promising potential for lithium-ion batteries. This work may provide inspiration for the design of alloy-type negative electrode materials for high-performance rechargeable batteries.