Bi2O3/Bi quasi-nanospheres in-situ embedded in N-doped porous carbon and reinforced via Bi-O-C bonding towards improved lithium storage performance

To mitigate the volume swelling and poor conductivity issues faced by Bi2O3 during Li storage, this work prepares an efficient Bi2O3-based composite through a simple freeze-drying and subsequent carbonization method, which improves the electrochemical performance of Bi2O3. The findings confirm that in this composite (Bi2O3/ Bi@PC) the Bi2O3 (containing small amounts of Bi) quasi-nanospheres are embedded within an N-doped porous carbon matrix (PC) and formation of Bi-O-C chemical bonding between Bi2O3/Bi and carbon matrix. The electrochemical characterization results demonstrate that PC physical embedding and Bi-O-C chemical bonding dual combination endows Bi2O3/Bi@PC with enhanced conductivity, improved Li+ diffusion coefficient and reinforced structural stability during cycle. As a result, Bi2O3/Bi@PC exhibits outstanding electrochemical performance, with 451.4 and 309.3 mAh g- 1 after 400 and 600 cycles at 200 and 1000 mA g- 1 , respectively. This study may provide essential guidance for future preparing advanced Bi-based anodes for lithium-ion batteries through a simple and efficient strategy.