Zhang Hao, Li Qiubo, Xu Xinyue, Yang Hui, Li Guodong, Liu Zhaolu, Liao Mochou, Xu Jie, Li Xun-Lu, Wang Nan, Zhang Junxi, Peng Haoyang, Cao Yongjie
Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power, Shanghai 200090, PR China.
Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, PR China.
J Colloid Interface Sci. 2025 Jan 15;678(Pt B):20-29. doi: 10.1016/j.jcis.2024.08.054. Epub 2024 Aug 10.
The off-stoichiometric compound NaFe(PO) (NFPO) is a highly promising, cost-effective, and structurally robust cathode material for sodium-ion batteries (SIBs). However, the slowing Na-ion migration kinetics and poor interface stability have seriously limited its rate capability and air stability. In this work, we successfully synthesis a sodium titanium pyrophosphate (NaTiPO donated as NTPO) coating NFPO (denoted as NFPO-NTPO) cathode material via a liquid phase coating method for SIBs. After optimizing NTPO content, at 0.1C, NFPO-NTPO-4 % cathode achieves a reversible specific capacity of 108.4 mAh g. Remarkably, it maintains 88.39 % capacity at 10C comparing to 0.1C and stabilizes over 3000 cycles with 92.66 % retention rate. Moreover, it retains 88.89 % capacity after 5000 cycles at 20C, even after 28 days of air exposure. The NFPO-Ti cathode, alongside the complete battery system, exhibits remarkable electrochemical performance across a broad temperature range spanning from -40 to 60 ℃.
非化学计量化合物NaFe(PO)（NFPO）是一种极具潜力、成本效益高且结构稳定的钠离子电池（SIBs）正极材料。然而，钠离子迁移动力学缓慢和界面稳定性差严重限制了其倍率性能和空气稳定性。在这项工作中，我们通过液相包覆法成功合成了一种用于SIBs的焦磷酸钠钛（NaTiPO，简称为NTPO）包覆NFPO（记为NFPO-NTPO）正极材料。优化NTPO含量后，在0.1C下，NFPO-NTPO-4%正极实现了108.4 mAh g的可逆比容量。值得注意的是，与0.1C相比，它在10C时保持88.39%的容量，并在3000次循环中稳定，保留率为92.66%。此外，在20C下5000次循环后，即使在空气暴露28天后，它仍保留88.89%的容量。NFPO-Ti正极与完整的电池系统一起，在-40至60℃的宽温度范围内表现出卓越的电化学性能。
