Bismuthene from sonoelectrochemistry as a superior anode for potassium-ion batteries
Bismuthene from sonoelectrochemistry as a superior anode for potassium-ion batteries
复制标题
声电化学中的铋作为钾离子电池的优质阳极
DOI：
10.1039/c9ta11000c
复制
发表时间：
2020-01-07
影响因子：
11.9
通讯作者：
Wu, Yingpeng
中科院分区：
文献类型：
--
作者：
Shen, Chao;Cheng, Tianle;Wu, Yingpeng
铋具有层间距大、平均自由程长、体积容量高（3800 mA h L-1）和环境友好的层状结构，是一种很有潜力的PIB阳极材料。铋烯是一种二维层状结构，可以通过机械或化学方法从铋中剥离。铋的独特结构有利于钾离子的扩散、电解质的渗透以及缓冲沿着c轴的体积变化，从而提高PIB的阳极性能。提出了一种超声波辅助电化学剥离法制备超薄少层铋纳米片的方法。将所制备的FBN用作KIB中的阳极，并在2.5、5、10和15 A g（-1）的电流密度下分别提供423、356、275和227 mA h g（-1）的高度稳定的容量。在20 A g（-1）下，循环2500次以上，无明显衰减，容量超过200 mA h g（-1），实现了KIB优良的倍率性能和长期循环稳定性。通过深入的表征和理论计算，阐明了其优异电化学性能的机理。这项工作为制备可扩展的超薄纳米片提供了一种新的策略，该纳米片作为储能系统中阳极的有希望的候选者。
Bismuth has a great potential as an anode for PIBs, due to its layered structure with a large interlayer spacing, long mean free path, high volumetric capacity (3800 mA h L-1) and environmental friendliness. Bismuthene, a 2D-layered structure, can be exfoliated from bismuth by mechanical or chemical methods. The unique structure of bismuthene is beneficial to the diffusion of potassium, penetration of the electrolyte, and buffering of the volume change along the c-axis, which will boost the anode performance of PIBs. An ultrasonication-assisted electrochemical exfoliation method was proposed in this study to prepare ultra-thin few layered bismuthene nanosheets (FBNs) simply and quickly. The as-prepared FBNs were employed in KIBs as an anode and delivered highly stable capacities of 423, 356, 275 and 227 mA h g(-1) at the current densities of 2.5, 5, 10, and 15 A g(-1), respectively. There was no obvious decay over 2500 cycles with a capacity of over 200 mA h g(-1) at 20 A g(-1), realizing excellent rate-capability and long-term cycling stability in KIBs. Furthermore, the mechanism of the excellent electrochemical performances was elucidated via in-depth characterization and theoretical calculations. This work provides a new strategy to prepare scalable ultra-thin nanosheets, which act as a promising candidate for the anode in energy storage systems.