In Situ Plastic-Crystal-Coated Cathode toward High-Performance Na-Ion Batteries

作者：Haibo Wang, Feixiang Ding, Yuqi Wang, Zhen Han, Rongbin Dang, Hao Yu, Yang Yang, Zhao Chen, Yuqi Li, Fei Xie, Shiguang Zhang, Hongzhou Zhang, Dawei Song, Xiaohui Rong, Lianqi Zhang, Juping Xu, Wen Yin, Yaxiang Lu, Ruijuan Xiao, Dong Su, Liquan Chen, Yong‐Sheng Hu · 发表于：ACS Energy Letters · 年份：2023 · DOI：10.1021/acsenergylett.3c00009 · 被引用次数：134 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Extraction and Separation Processes

Cathode materials are critical for Na-ion batteries while facing challenges due to the instability of the structure and interfaces. In this work, we propose a strategy to achieve an in situ plastic-crystal Na 3–3 x Al x PO 4 coating and bulk Al doping for an O3-NaNi 0.4 Fe 0.2 Mn 0.4 O 2 cathode through a simple one-step method. Na 3–3 x Al x PO 4 exhibits high ion transport performance due to its unique “paddle-wheel” mechanism. The in situ formed Na 3–3 x Al x PO 4 could consume the residual alkali compounds and induce the formation of a Na-deficient phase, thus leading to enhanced Na + transport kinetics. Furthermore, strong Al–O bonds formed in the bulk further enhance the crystal structure stability. In a full cell, the capacity retention rate reached 70% after 500 cycles, making its commercial operation possible. Altogether, these results suggest that the in situ plastic-crystal-coating strategy can significantly improve the surface and bulk structure stability of NaNi 0.4 Fe 0.2 Mn 0.4 O 2, thus leading to improved electrochemical performance.