小批量磷酸钒锂正极材料的制备研究

Preparation of small batch carbon-coated lithium-vanadium phosphate cathode materials

以Li_2CO_3,V_2O_5,NH_4H_2P O_4为主要原料,以蔗糖和柠檬酸为碳源,作为还原剂并对目标材料进行包覆,以无水乙醇为分散剂,经球磨制得前驱体,N_2保护下800℃高温焙烧16 h,制备了系列纯相、稀土钐掺杂的碳包覆磷酸钒锂复合正极材料。并进行了单一蔗糖和蔗糖、柠檬酸混糖作碳源对比,磷酸钒锂纯相和钐掺杂对比,实验室小剂量和小批量(0.5～1.0 kg)制备对比。X射线衍射光谱法(XRD)、扫描电子显微镜法(S EM)及电化学测试表明,所制备的系列目标材料均具有单斜Li_3V_2(P O_4)_3结构特征,以蔗糖、柠檬酸为混合碳源的目标材料碳包覆更均匀,循环和倍率等电化学性能良好。

The precursor was prepared after ball grinding the main raw material of Li2CO3, V2O5and NH4H2PO4 with sucrose and critric acid as the carbon source and as a reducing agent to coat the target materials, and with anhydrous ethanol as dispersant. Under N2 protection at 800 ℃ roasted for 16 h, we prepared the composite cathode material of pure phase, rare earth samarium doping carbon-coated Li3V2 (PO4)3. In addition, the single sucrose as carbon sources and the sucrose and citric acid as mixed carbon sources, the pure lithium vanadium phosphate and samarium doped lithium vanadium phosphate, the laboratory small dose and the small batch (0.5 kg) were compared respectively. XRD, SEMand electrochemical tests show that the prepared target materials Li3V2(PO4)3 are monoclinic, the carbon-coating is more uniform and the cycle performance and rate performance is excellent with sucrose and citric acid as the mixed carbon sources.