▎ 摘　　要

Na3V2(PO4)(3) is an attractive electrode material for Na-ion batteries due to high ionic conductivity and good stability, but suffers from low electronic conductivity. Here, a graphene-bound Na3V2(PO4)(3) film is fabricated by simple vacuum co-filtration and thermal treatment, which can be directly used as both cathode and anode for Na-ion batteries. In the film, Na3V2(PO4)(3) nanoparticles are homogeneously bounded in a 3D continuous graphene network. As graphene acts as binder, conductive agent, and current collector simultaneously, the content of Na3V2(PO4)(3) can easily reach up to about 93.3 wt%, promising a superior capacity calculated based on the total mass of the electrode. Furthermore, the 3D conductive graphene provides efficient electron pathways and buffers volume change during cycling. Therefore, the graphene-bound Na3V2(PO4)(3) electrode exhibits high capacity (114.6 mAh g(-1) at 1 C as cathode, 69.1 mAh g(-1) at 50 mA g(-1) as anode), ultra-long cycle stability (only about 0.005% of the capacity is decayed per cycle during 10 000 cycles) and excellent rate performance (89.7 mAh g(-1) at 30 C as cathode, 42.3 mAh g(-1) at 2 A g(-1) as anode). As a result, we believe the graphene-bound Na3V2(PO4)(3) film is a promising candidate for Na-ion batteries. (C) 2018 Elsevier Ltd. All rights reserved.