A pure phase material Na4 MnV(PO 4 )3 @C(NMVP@C)was prepared by sol-gel method, the Na4 MnV (PO 4 )3 was synthesized by graphene,and the Jahn-Teller effect was inhibited by reducing the content of Mn in the material.Electrochemical performance of materials were tested by galvanostatic discharge-charge method.The results show that when the Na4 MnV(PO 4 )3 @C was used as a cathode material for sodium ion batteries,the specific capacity of 2.5—4.0 V was 105 mA·h/g, the average voltage was 3.6 V,and the capacity retention rate after 30 cycles was 63%.The capacity retention rate of composite material after 30 cycles was 71%.The specific capacity of low manganese material Na3 .5 Mn0.5 V1 .5 (PO 4 )3 @C was 110 mA·h/g in 2.5—4.2 V,and the capacity retention rate after 50 cycles was 90%.The capacity retention rate of material was greatly improved.%用溶胶-凝胶法制备纯相Na4 MnV(PO 4)3@C材料,对Na4 MnV(PO 4)3@C进行石墨烯复合,通过降低材料中Mn含量抑制体系的Jahn-Teller效应,并利用恒流充放电方法测试材料的电化学性能.结果表明:Na4 MnV(PO 4)3@C作为钠离子正极材料,在2.5~4.0 V下的比容量为105 mA·h/g,平均电压为3.6 V,30次循环后的容量保持率为63%;复合后的材料在30次循环后,容量保持率为71%;低锰材料Na3.5 Mn0.5 V1.5(PO 4)3@C在2.5~4.2 V下的比容量为110 mA·h/g,50次循环后的容量保持率为90%,材料的容量保持率得到大幅度提高.
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