固相-水热法制备LiFePO4-Li3V2(PO4)3复合材料及其电化学性能

摘要

分别采用固相-水热法和球磨法制备磷酸亚铁锂-磷酸钒锂复合正极材料(LiFePO4-Li3V2(PO4)3).电化学性能测试表明,LiFePO4-Li3V2(PO4)3复合正极材料的电化学性能远远高于LiFePO4和Li3V2(PO4)3单独作为正极材料的性能,并且以固相-水热法制备的复合材料性能优于以球磨法制得的复合材料.研究发现LiFePO4-Li3V2(PO4)3复合材料有4个氧化还原峰,相当于LiFePO4和Li3V2(PO4)3氧化还原峰的叠加.采用固相-水热法制备的LiFePO4-Li3V2(PO4)3复合材料形貌较为规则,且有新相物质产生,这是导致其电化学性能较好的原因.%LiFePO4-Li3V2(PO4)3 composites were synthesized by solid-hydrothermal method and by ball milling,respectively.The electrochemical performance of the solid-hydrothermally obtained materials (C-LFVP) was significantly improved compared with LiFePO4 (LFP) and Li3V2(PO4)3 (LVP),and it was also much better than that of the ball-milled LiFePO4-Li3V2(PO4)3 (P-LFVP).C-LFVP and P-LFVP both had four REDOX peaks (voltage plateaus),which coincided with that of LFP and LVP.Some new trace substances were found in C-LFVP which had more perfect morphology,this was responsible for the better electrochemical performance of C-LFVP than P-LFVP.