A high rate capability and long lifespan symmetric sodium-ion battery system based on a bipolar material Na2LiV2(PO4)3/C

Sodium ion batteries have been considered as one of the promising candidates for large-scale energy storage systems. From the application perspective of an integrated sodium ion full-cell system, it is important to develop a practical sodium-ion full-cell system with excellent cycling life, superior safety, and good rate capability to tolerate the frequent current impulses during the grid peak period. Therefore, exploring appropriate electrode materials with excellent electrochemical properties is the key issue. A rhombohedral structured two-phase Na 2 LiV 2 (PO 4 ) 3 /C nanocomposite has been successfully synthesized and employed as both cathode and anode material. It exhibits excellent electrochemical performance, including high capacity, superior rate capability, and remarkable cycling performance. In particular, it shows excellent long-term cycling stability with a capacity retention of about 83% and 100% after 3000 cycles at 10C, for the cathode and anode, respectively. Moreover, the symmetric sodium-ion full cells made of the Na 2 LiV 2 (PO 4 ) 3 /C nanocomposite have good rate capability and cycling stability, which verifies the feasibility of practical applications of the Na 2 LiV 2 (PO 4 ) 3 /C nanocomposite in sodium-ion batteries