Structural and electrochemical properties of Fe-doped Na2Mn3-Fe-x(x)(P2O7)(2)cathode material for sodium ion batteries
Structural and electrochemical properties of Fe-doped Na2Mn3-Fe-x(x)(P2O7)(2)cathode material for sodium ion batteries
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Fe掺杂Na2Mn3-Fe-x(x)(P2O7)(2)钠离子电池正极材料的结构与电化学性能
DOI：
10.1016/j.jpowsour.2017.10.019
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发表时间：
2017
影响因子：
9.2
通讯作者：
Kuang Quan
中科院分区：
文献类型：
--
作者：
Liu Huatao;Zhao Yanming;Zhang Hui;Lian Xin;Dong Youzhong;Kuang Quan
采用溶胶-凝胶法制备了一系列Fe掺杂的Na_2 Mn_（3-x）Fe_x（P_2 O_7）_2（x= 0.0，0.5，1.0，1.5和2.0）化合物。Rietveld精修结果表明，在本实验条件下，虽然不存在Na 2Fe 3（P2 O 7）2，但在0 ≤ x ≤ 2范围内，可以得到单相的三斜晶系Na 2 Mn 3-xFex（P2 O 7）2，晶胞参数（包括a，B，candV）随着x的增加而减小。结果表明，Na_2Mn_3（P_2O_7）_2在1.5 V ~ 4.5 Vvs.Na ~+/Na范围内具有良好的电化学活性，但其倍率性能和容量保持率较低。而Fe掺杂的Na_2 Mn_（3-x）Fe_x（P_2 O_7）_2（0 ≤x≤ 2）的电化学性能明显提高，循环性能和倍率性能均比未掺杂的样品有明显改善。当Fe掺杂量大于x = 0.5时，钠离子的扩散系数可提高两个数量级。
A series of Fe-doped Na2Mn3-xFex(P2O7)2(x= 0.0, 0.5, 1.0, 1.5 and 2.0) compounds have been successfully prepared by using sol-gel method. Rietveld refinement results indicate that single phase Na2Mn3-xFex(P2O7)2with triclinic structure can be obtained within 0 ≤ x ≤ 2 although no Na2Fe3(P2O7)2existing under our experimental conditions, and the cell parameters (includinga,b,candV) are decreasing with the increasing ofx. Our results reveal that Na2Mn3(P2O7)2exhibits an electrochemical activity in the voltage range of 1.5 V–4.5 Vvs.Na+/Na when using as the cathode material for SIBs although it gives a limited rate capability and poor capacity retention. However, the electrochemical performance of Fe-doped Na2Mn3-xFex(P2O7)2(0 ≤x≤ 2) can be improved significantly where cycle performance and rate capability can be improved significantly than that of the pristine one. Sodium ion diffusion coefficient can be increased by about two orders of magnitude with the Fe-doping content higher than x = 0.5.