Nanosheets Bi<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> as an Anode Material for Advanced\nLithium-Ion Batteries

Bi<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> is undoubtedly\none of\nthe best anode materials for Li-powered batteries on the market. However,\nits pronounced capacity fading and poor cycle performance are significant\nobstacles to its commercialization. At present, the Bi<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> nanosheets are prepared via a simple\none-step hydrothermal method from bismuth nitrate and sodium carbonate.\nThe nanosheets have a smooth surface and a preferred (110) plane orientation.\nThe optimal mole ratio of Bi<sup>3+</sup>/CO<sub>3</sub><sup>2–</sup> is definitively proven to be lower than 1:2. The as-prepared Bi<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> nanosheets exhibit a decent lithium-ion\nstorage performance, with a high specific capacity (up to 309.3 mA\nh g<sup>–1</sup> at 1.0 A g<sup>–1</sup>), good cycling\nstability (nearly 100% capacity retention referenced to the 20th cycle\nafter 400 cycles), superior rate capability (232.6 mA h g<sup>–1</sup> at 3.0 A g<sup>–1</sup>), and quick diffusion kinetic property\n(the Li-ion diffusion coefficient is 2.78 × 10<sup>–15</sup> cm<sup>2</sup> s<sup>–1</sup>), where the Faradaic reaction\nis the dominant contribution. These promising results open possibilities\nfor exploring Bi<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> and related\nmaterials in energy storage applications.