Enhanced sodium storage performance of NASICON-structured NaTi2(PO4)3/C decorated with graphene

NaTi2(PO4)(3)/C composite decorated with graphene (NTP-C-G) was prepared via a facile sol-gel method and subsequent high-temperature calcination, and applied in sodium ion battery. Three-dimensional continuous mixture was formed by NaTi2(PO4)(3)/C and graphene, and the graphene had no obvious effect on the crystal form of NaTi2(PO4)(3)/C. Compared with NaTi2(PO4)(3)/C (NTP-C), NTP-C-G showed outstanding rate performance. NTP-C-G delivered discharge capacity of 156.3 and 72.1 mAh g(-1) at current density of 0.2 and 2 A g(-1), respectively, 45.5 and 47.0 mAh g(-1) larger than those of NTP-C. Moreover, cycling performance of two composites was evaluated by long-term galvanostatic charge-discharge tests, and NTP-C-G demonstrated better cycling performance compared with NTP-C. NTP-C-G delivered discharge capacity of 63.9 mAh g(-1) at 2 A g(-1) after 1000 cycles, increasing by 45.1 mAh g(-1) compared with NTP-C. Excellent electrochemical performance may be ascribed to the continuous conductive network formed by graphene, which increases the conductivity of electrons and sodium ions. Our work proves that NaTi2(PO4)(3)/C modified with graphene exhibits excellent sodium storage performance, and it can act as a promising electrode for sodium ion batteries.