Graphene modified Li3V2(PO4)3 as a high-performance cathode material for lithium ion batteries

Highlights: ► Graphene-modified Li3V2(PO4)3 composites are produced by spray–drying process. ► 3D network graphene and Li3V2(PO4)3 primary nanoparticles interlace with each other. ► The citric acid-derived amorphous carbon interrupts the stacking of GNS and minimizes in-plane anisotropy of electronic migration within graphene layers. ► LVP/(G + C) sample exhibits the best electrochemical performances. - Abstract: In this paper, graphene-modified Li3V2(PO4)3 composites have been developed as Li-ion battery cathode materials with high specific capacity and excellent cycling stability. The composites are prepared by spray–drying process using graphene oxide nanosheet and citric acid as carbon source. X-ray diffraction patterns demonstrate that the as-prepared samples are well crystallized with orderly monoclinic structures. SEM and TEM images reveal that the 3D network graphene and Li3V2(PO4)3 primary nanoparticles interlace with each other. The citric acid-derived amorphous carbon species interrupt the stacking of graphene sheets and minimize in-plane anisotropy of electronic migration within graphene layers, which would facilitate fast electron migration and Li+ diffusion throughout the micro-sized spherical secondary particles. The discharge capacity of the composite could respectively achieve 131.4 and 181.5 mAh g−1 in the voltage range 3.0–4.3 V and 3.0–4.8 V at 0.1C discharge rate, which almost reach the theoretical capacity of the cathode material. Both of them nearly showed no capacity decay at 0.1C charging and discharging rate after long cycles.