Enhancing Kinetic Performance and Structural Stability of Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) Cathode via La Doping Defect Engineering

作者：Xin Chen, Jiahui Wu, Jingyao Zeng, Caiyan Shen, Yuejun Wang, Yangyang Xie, Guorong Hu, Ke Du, Zhongdong Peng, Yanbing Cao · 发表于：Small · 年份：2025 · DOI：10.1002/smll.202412260 · 被引用次数：11 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Advanced Battery Technologies Research

Abstract Due to the strong electronegativity of P in the anion group and the strong P─O covalent bond, NFPP exhibits low electronic and ionic conductivity, hindering its rate capability. A doping modification strategy of selecting La 3+ with a large ion radius at Na site has been designed, and the nano‐micro architectural Na 4‐3x La x □ 2x Fe 3 (PO 4 ) 2 (P 2 O 7 )/C (0≤x≤0.04) cathode material with Na vacancies is successfully synthesized via a scalable preparation route. Introducing positively charged substitutional point defects and charged vacancies through doping La 3+ not only broadens the Na + transport channels but also reduces lattice stress and stabilizes the crystal bulk structure during long‐term cycling for La 3+ as pillars. Additionally, high valence La 3+ doping enhances the effective charge carrier concentration and improves material conductivity. Consequently, the kinetic performance of Na + migration is significantly enhanced. The optimal Na 3.91 La 0.03 □ 0.06 Fe 3 (PO 4 ) 2 (P 2 O 7 )/C (NFPP/C‐La3) exhibits the best electrochemical performance. The synthesized NFPP/C‐La3 exhibits excellent rate performance (99.45 mAh g −1 at 20 C) and long‐term cycle stability (92.36% of capacity retention over 1000 cycles at 10 C). These results provide the importance and prospect of the high valence ion doping for NFPP/C with high rate stability.