Poly(vinylalcohol) (PVA) Assisted Sol-Gel Fabrication of Porous Carbon Network-Na 3 V 2 (PO 4 ) 3 (NVP) Composites Cathode for Enhanced Kinetics in Sodium Ion Batteries.

Na 3 V 2 (PO 4 ) 3 is regarded as one of the promising cathode materials for next-generation sodium ion batteries, but its undesirable electrochemical performances due to inherently low electrical conductivity have limited its direct use for applications. Motivated by the limit, this study employed a porous carbon network to obtain a porous carbon network-Na 3 V 2 (PO 4 ) 3 composite by using poly(vinylalcohol) assised sol-gel method. Compared with the typical carbon-coating approach, the formation of a porous carbon network ensured short ion diffusion distances, percolating electrolytes by distributing nanosized Na 3 V 2 (PO 4 ) 3 particles in the porous carbon network and suppressing the particle aggregation. As a result, the porous carbon network-Na 3 V 2 (PO 4 ) 3 composite exhibited improved electrochemical performances, i.e., a higher specific discharge capacity (~110 mAh g -1 at 0.1 C), outstanding kinetic properties (~68 mAh g -1 at 50 C), and stable cyclic stability (capacity retention of 99% over 100 cycles at 1 C).