Abstract: A pure phase material Na₄MnV(PO₄)₃@C(NMVP@C) was prepared by solgel method, the Na₄MnV(PO₄)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 Na₄MnV(PO₄)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 Na_3.5Mn_0.5V_1.5(PO₄)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.

Key words: electroche
mical property, sodiumion battery, pure phase