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 Li_1.20Mn_0.54Ni_0.13Co_0.13O₂ 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.