Wang Yan, Kuang Yongxin, Cui Jie, Xu Xijun, Li Fangkun, Wu Yiwen, Sun Zhaoyu, Fan Weizhen, Wu Yanxue, Zhao Jingwei, Zeng Zhiyuan, Liu Jun, Huo Yanping
School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, PR China.
Analytical and Testing Centre, South China University of Technology, Guangzhou 510640, P. R. China.
Nano Lett. 2024 Dec 4;24(48):15242-15251. doi: 10.1021/acs.nanolett.4c03453. Epub 2024 Nov 19.
Huge volume changes of bismuth (Bi) anode leading to rapid capacity hindered its practical application in sodium-ion batteries (SIBs). Herein, porous Bi@C (P-Bi@C) microspheres consisting of self-assembled Bi nanosheets and carbon shells were constructed via a hydrothermal method combined with a carbothermic reduction. The optimized P-Bi@C-700 (annealed at 700 °C) demonstrates 359.8 mAh g after 1500 cycles at 1 A g. characterization and density functional theory calculations verified that this P-Bi@C-700 relieves the volume expansion, facilitates Na/electron transport, and possesses an alloying-type storage mechanism. Notably, P-Bi@C-700 also achieved 360.8 and 370.3 mAh g at 0.05 A g under 0 and 60 °C conditions, respectively. NaV(PO)//P-Bi@C-700 exhibits a capacity of 359.7 mAh g after 260 cycles at 1 A g. These hierarchical microspheres effectively moderate the volume fluctuation, preserving structural reversibility, thereby achieving superior Na storage performance. This self-template strategy provides insight into designing high-volumetric capacity alloy-based anodes for SIBs.
铋（Bi）负极的巨大体积变化导致容量迅速衰减，阻碍了其在钠离子电池（SIBs）中的实际应用。在此，通过水热法结合碳热还原构建了由自组装Bi纳米片和碳壳组成的多孔Bi@C（P-Bi@C）微球。优化后的P-Bi@C-700（在700°C退火）在1 A g下循环1500次后，容量为359.8 mAh g。表征和密度泛函理论计算证实，这种P-Bi@C-700缓解了体积膨胀，促进了Na/电子传输，并具有合金化型存储机制。值得注意的是，P-Bi@C-700在0和60°C条件下，0.05 A g时的容量分别达到360.8和370.3 mAh g。NaV(PO)//P-Bi@C-700在1 A g下循环260次后，容量为359.7 mAh g。这些分级微球有效地缓解了体积波动，保持了结构可逆性，从而实现了优异的钠存储性能。这种自模板策略为设计用于SIBs的高体积容量合金基负极提供了思路。
