Hierarchical fragmented Na3V2(PO4)3@reduced graphene composites with enhanced sodium-ion storage performance

Na3V2(PO4)3 (NVP), as a typical polyanionic compound with a unique three-dimensional NASICON structure that promotes the rapid migration of Na+, is a promising cathode material, while its low electronic conductivity limits its commercial potential. In this work, we synthesized a fragmented composite which is reduced graphene oxide loaded NVP particles (NVP@FG) in situ via a sol-gel method and annealing treatment. The unique structural design creates a fast electron conduction network, enhancing Na+ transport. Kinetic testing results indicate that optimized NVP@FG exhibits an excellent Na+ diffusion rate, achieving a notable discharge capacity of 114.5 mAh g- 1 at 0.2 C. Furthermore, NVP@FG exhibits an initial capacity of 85.1 mAh g- 1 at 10 C and retains 97.5 % of its capacity after 1800 cycles, with a minimal capacity decay of 0.00127 % per cycle, demonstrating excellent cycle stability. Additionally, NVP@FG||hard carbon full cell also demonstrates favorable electrochemical performance, confirming that NVP@FG is a prospective material for cathodes in sodium-ion batteries.