首页|In situ atomic-scale tracking of unusual interface reaction circulation and phase reversibility in(de)potassiated alloy-typed anode

In situ atomic-scale tracking of unusual interface reaction circulation and phase reversibility in(de)potassiated alloy-typed anode

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Alloy-typed anode materials,endowed innately with high theoretical specific capacity,hold great pro-mise as an alternative to intercalation-typed counterparts for alkali-ion batteries.Despite tremendous efforts devoted to addressing drastic volume change and severe pulverization issues of such anodes,the underlying mechanisms involving dynamic phase evolutions and reaction kinetics have not yet been fully comprehended.Herein,taking antimony(Sb)anode as a representative paradigm,its microscopic operating mechanisms down to the atomic scale during live(de)potassiation cycling are systematically unraveled using in situ transmission electron microscopy.Highly reversible phase transformations at single-particle level,that are Sb (←→)KSb2 (←→)KSb (←→)K5Sb4 (←→)K3Sb,were revealed during cycling.Meanwhile,multiple phase interfaces associated with different reaction kinetics coexisted and this phe-nomenon was properly elucidated in the context of density functional theory calculations.Impressively,previously unexplored unidirectional circulation of reaction interfaces within individual Sb particle is confirmed for both potassiation and depotassiation.Based on the empirical results,the surface diffusion-mediated potassiation-depotassiation pathways at single-particle level are suggested.This work affords new insights into energy storage mechanisms of Sb anode and valuable guidance for tar-geted optimization of alloy-typed anodes(not limited to Sb)toward advanced potassium-ion batteries.

Alloy-typed anodePotassium storage mechanismIn situ transmission electron microscopyReaction interface

Lin Su、Ruining Fu、Shuangying Lei、Yuchen Pan、Chongyang Zhu、Pengcheng Liu、Feng Xu

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SEU-FEI Nano-Pico Center,Key Laboratory of MEMS of the Ministry of Education,Southeast University,Nanjing,210096,China

National Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaBig Data Computing Center of Southeast University

1217404951972058

2024

10.1016/j.jechem.2024.03.046

能源化学
中国科学院大连化学物理研究所 中国科学院成都有机化学研究所

能源化学

CSTPCDEI
影响因子：0.654
ISSN：2095-4956
年,卷(期)：2024.95(8)