Recent research progress in the application of Na<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub>F<sub>3</sub> cathode materials in sodium-ion batteries: synthesis, modification, and battery optimization
Yining Liang, Lin Xu, Zhengjian Chen, De Ning, Zhipeng Sun
Abstract
Sodium vanadium fluorophosphate [Na3V2(PO4)2F3, NVPF], as a sodium (Na) super ionic conductor material, has attracted significant interest as a very promising cathode material for sodium-ion batteries due to its structural stability, rapid ion transport capability, and high operating potential. However, the insulating [PO4] units in NVPF isolate the V atoms, which results in low intrinsic electron conductivity and poor overall electrochemical performance, and the high cost also represents critical challenge that has impeded its widespread use. In recent years, the research focus has shifted to an enhancement of scalable fabrication technologies and improvement of operational robustness under extreme conditions. This has meant a realignment of the research paradigm from the modification of single materials to an adaptive design of the entire battery system. This review assesses the research conducted on NVPF cathodes over the past three years from several perspectives, focusing on the feasible application of materials over a wide temperature range at high voltages, summarizing the challenges and required development strategies in future research.