A Dealloying Synthetic Strategy for Nanoporous Bismuth-Antimony Anodes for Sodium Ion Batteries
A Dealloying Synthetic Strategy for Nanoporous Bismuth-Antimony Anodes for Sodium Ion Batteries
复制标题
钠离子电池纳米孔铋锑负极的脱合金合成策略
DOI：
10.1021/acsnano.8b00643
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发表时间：
2018-04-01
期刊：
影响因子：
17.1
通讯作者：
Zhang, Zhonghua
中科院分区：
文献类型：
--
作者：
Gao, Hui;Niu, Jiazheng;Zhang, Zhonghua
金属基负极由于其高理论容量和低钠化电位，最近在钠离子电池（SIB）中引起了广泛关注。然而，由于在（脱）钠过程中严重的体积变化和粉碎导致循环性能较差，阻碍了它们的进步。为了解决这个问题，本文提出了一种合金化策略，并通过三元镁基前驱体的脱合金来制备纳米多孔铋（Bi）-锑（Sb）合金。作为SIBs的阳极，由于多孔结构、合金化效应和适当的Bi/Sb原子比，纳米多孔Bi2Sb6合金在1 A/g下表现出超长循环性能（10 000次循环），相当于每次循环容量衰减仅为0.0072%。更重要的是，通过使用原位X射线衍射和密度泛函理论计算，确定了Bi-Sb合金的放电/充电过程的（去）钠化机制（（Bi，Sb）Na（Bi，Sb）Na-3（Bi，Sb））。
Metal-based anodes have recently aroused much attention in sodium ion batteries (SIBs) owing to their high theoretical capacities and low sodiation potentials. However, their progresses are prevented by the inferior cycling performance caused by severe volumetric change and pulverization during the (de)sodiation process. To address this issue, herein an alloying strategy was proposed and nanoporous bismuth (Bi)-antimony (Sb) alloys were fabricated by dealloying of ternary Mg-based precursors. As an anode for SIBs, the nanoporous Bi2Sb6 alloy exhibits an ultralong cycling performance (10 000 cycles) at 1 A/g corresponding to a capacity decay of merely 0.0072% per cycle, due to the porous structure, alloying effect and proper Bi/Sb atomic ratio. More importantly, a (de)sodiation mechanism ((Bi,Sb) Na(Bi,Sb) Na-3(Bi,Sb)) is identified for the discharge/charge processes of Bi-Sb alloys by using operando X-ray diffraction and density functional theory calculations.