Accelerating Na+ Diffusion Kinetics of Na3V2(PO4)3 Cathode for High-Performance Sodium-Ion Batteries via In Situ Configured Cross-Linked Carbon Networks

Na3V2(PO4)3 has garnered significant attention as a promising cathode material for sodium-ion batteries due to its excellent ionic conductivity and robust structural stability. However, its further large-scale practical application has been hindered by its low electrical conductivity and poor interface kinetics. Therefore, it is reported in this study that the discharging/charging cycling and rate performance of Na3V2(PO4)3 cathodes are dramatically improved by the uniformly formed 3D carbon networks. Evidently, the Na3V2(PO4)3 cathode material prepared under the optimized conditions exhibited a relatively high initial capacity of 109.30 mAh/g at 0.1C with an initial Coulombic efficiency (ICE) of 99% and achieved an appreciable capacity of 99.42 mAh/g with a capacity retention of 96.39% after 400 cycles at 2C. Based on different characterizations and electrochemical performances, both the formation and sodium storage mechanism of Na3V2(PO4)3-based composite cathodes were initially concluded, which is significant and important for improving electrical conductivity and designing practical carbon-cladding strategies for Na-ion batteries.