Superior high-rate capability of Na3(VO(0.5))2(PO4)2F2 nanoparticles embedded in porous graphene through the pseudocapacitive effect.

Na3(VO(0.5))2(PO4)2F2 nanoparticles embedded in porous graphene have been reported as a superior high-rate cathode material for sodium-ion batteries, exhibiting an excellent electrochemical performance with a high reversible capacity of 100 mA h g(-1) at 1 C, 77 mA h g(-1) at 50 C, and a capacity retention of 73% after 1000 cycles at 50 C. In particular, a significant contribution of the pseudocapacitive effect to the Na-storage capacity has been found for the first time.