电池正极材料Li_3V_(2-2x/3)Mn_x(PO_4)_3/C的制备及性能研究

Synthesis and Electrochemical Characteristics of Cathode Materials Li_3V_(2-2x/3)Mn_x(PO_4)_3/C

以V2O5、NH4H2PO4、Li2CO3、(CH3COO)2Mn.4H2O原料,以葡萄糖和抗坏血酸为复合还原剂及碳源,通过常温还原-低温烧结法制备锂离子电池正极材料Li3V(2-2x/3)Mnx(PO4)3/C(x=0,0.03,0.06,0.09,0.12)。通过X射线衍射(XRD),扫描电镜(SEM),恒电流充放电测试对该正极材料的物相、结构、微观形貌以及电化学性能进行了表征。结果表明,Mn2+的掺杂对磷酸钒锂电化学性能的发挥影响很大,其中当锰掺杂量x=0.09时材料表现出最佳的电化学性能,0.2 C倍率条件下首次放电比容量131 mAh/g,循环50次后容量衰减仅为4.02%。

Composite cathode material Li3V（2-2x/3） Mnx （PO4）3/C（ x = 0,0.03,0.06,0.09,0.12 ） was obtained from chemical reduction and lithiation method by using V205, NH4H2PO4, Li2CO3, and （CH3COO）2Mn · 4H20 as raw mate- rials and glucose and aseorbic acid as reductant and carbon source. The structure and electrochemical performances of Li3V（2-2x3） Mnx（PO4）3/C was characterized by XRD, SEM, and galvanostatic charge/discharge. The results of electro- chemical measurements showed that Mn - doping can improve the electrochemical performance in significant measure. When x = 0.09, the electrochemical performance was better than that of others and its initial discharge capacity was 131 mAh/g at 0.2 C. There was only 4.02% capacity fade observed after 50 cycles.