Resolving the Origins of Superior Cycling Performance of Antimony Anode in Sodium‐ion Batteries: A Comparison with Lithium‐ion Batteries

• Published in: Angewandte Chemie Vol. 136; no. 11
• Main Authors: Shao, Ruiwen, Sun, Zhefei, Wang, Lei, Pan, Jianhai, Yi, Luocai, Zhang, Yinggan, Han, Jiajia, Yao, Zhenpeng, Li, Jie, Wen, Zhenhai, Chen, Shuangqiang, Chou, Shu‐Lei, Peng, Dong‐Liang, Zhang, Qiaobao
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 11.03.2024
• Subjects: Alloying; Alloys; Antimony; Antimony anode; Atomic interactions; Cycles; Electrochemical performance; Electrochemistry; Electrode materials; In situ transmission electron microscopy; Intermediates; Lithium; Lithium-ion batteries; Mechanical properties; Origins; Sodium; Sodium-ion batteries; Structural stability; Transmission electron microscopy
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202320183

Alloying‐type antimony (Sb) with high theoretical capacity is a promising anode candidate for both lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs). Given the larger radius of Na+ (1.02 Å) than Li+ (0.76 Å), it was generally believed that the Sb anode would experience even worse capacity degradation in SIBs due to more substantial volumetric variations during cycling when compared to LIBs. However, the Sb anode in SIBs unexpectedly exhibited both better electrochemical and structural stability than in LIBs, and the mechanistic reasons that underlie this performance discrepancy remain undiscovered. Here, using substantial in situ transmission electron microscopy, X‐ray diffraction, and Raman techniques complemented by theoretical simulations, we explicitly reveal that compared to the lithiation/delithiation process, sodiation/desodiation process of Sb anode displays a previously unexplored two‐stage alloying/dealloying mechanism with polycrystalline and amorphous phases as the intermediates featuring improved resilience to mechanical damage, contributing to superior cycling stability in SIBs. Additionally, the better mechanical properties and weaker atomic interaction of Na−Sb alloys than Li−Sb alloys favor enabling mitigated mechanical stress, accounting for enhanced structural stability as unveiled by theoretical simulations. Our finding delineates the mechanistic origins of enhanced cycling stability of Sb anode in SIBs with potential implications for other large‐volume‐change electrode materials. A systematic comparative study on the electrochemical performance and dynamic microstructural and mechanical changes of antimony anode in storing Li+/Na+ cations was carried out by combining in situ microscopic and spectroscopic analysis, density functional theory simulations, and finite‐element analysis. Full stepwise crystal transition with large lattice strains has been witnessed in Li‐storage system, while an unexplored two‐stage alloying/de‐alloying mechanism with polycrystalline and amorphous phases as intermediates is discovered in Na‐storage system, featuring enhanced resilience and less strain, contributing to high capacities and superior cyclability.