Negative Enthalpy Doping Stabilizes P2‐Type Oxides Cathode for High‐Performance Sodium‐Ion Batteries

作者：Yongcong Huang, Shuai Gu, Xin Xu, Zibing An, Xiaodong Han, Yulin Cao, Dongsheng He, Fangchang Zhang, Hao Guo, Yan Liu, Xingqun Liao, Guiyu Liu, Peiwen Liu, Feng Wu, Yingzhi Li, Zhenyu Wang, Zhiqiang Wang, Chao Ding, Yanfang Wang, Jingjing Chen, Mingyang Yang, Feng Jiang, Yonghong Deng, Zhenghe Xu, Zhouguang Lu · 发表于：Advanced Materials · 年份：2025 · DOI：10.1002/adma.202408012 · 被引用次数：50 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Supercapacitor Materials and Fabrication

Abstract P2‐type Na 0.67 Ni 0.33 Mn 0.67 O 2 (NNMO) as cathode material for sodium‐ion batteries (SIBs) largely suffers from continuous accumulation of local stress caused by destructive structural evolution and irreversible oxygen loss upon cycling, leading to rapid capacity degradation. Herein, a strategy of negative enthalpy doping (NED), wherein transition metal (TM) sites are substituted with 0.01 mol each Sn, Sb, Cu, Ti, Mg, and Zn to increase the stability of the TM layers, is proposed. The robust structure of NED‐NNMO significantly suppresses the P2 to O2 phase transition and improves the Na + kinetics upon long‐term cycling. Consequently, the NED‐NNMO exhibits much smoothened voltage platforms and improved oxygen redox reversibility, thus considerably extended lifetime as compared with the pristine NNMO sample. The NED‐NNMO delivers a high capacity of 138.9 mAh g −1 with an operation voltage of 3.51 V under 0.1 C and prominent capacity retention of 94.6% after 100 cycles under 1 C, and 90.0% over 3000 cycles under ultra‐high rate of 30 C, which is among the best over previous reports. Moreover, an ampere‐hour scale pouch cell based on the NED‐NNMO demonstrates an energy density of 139 Wh kg −1 . This work sheds light on a route of negative enthalpy doping to design high‐performance sodium‐ion batteries.