Reduced graphene oxide and carbon nanotube anchored NASICON-type NaTi2(PO4)3 nanocomposite anodes for high-rate performance sodium-ion batteries

NASICON-structured NaTi2(PO4)3 (NTP) anode consist of an open 3D framework is received as a zero-stress anode for Na-ion batteries. Herein, we have reported a novel NTP/GO/CNT nanocomposite anodes, in which NTP particles are engineered with reduce graphene oxide (rGO) and carbon nano tube (CNT) and wrapped using a low-cost facile sol-gel method. NTP-rGO10-CNT10 has been chosen as the optimum electrode after studying the effects of rGO/CNT ratio on the electrochemical performance of NTP. The combine effect of structural integrity, high electronic conductivity and high ionic diffusivity in NTP-rGO10-CNT10 leads to excellent electrochemical performance with regards to specific capacity (124 mA h g-1 at 100 mA g-1), remarkable high-rate cycleability (62.5% capacity retention after 400 cycles at 10 C), and excellent rate capability (87 mA h g-1 at 25C). Using cyclic voltammetry investigation, we have estimated the capacitive and faradaic contributions to the total capacities of the composite electrode at various rate. Besides, carbon incorporated NVOPF obtained by carbothermal reduction delivers a specific discharge capacity of 106 mA h g-1 as cathode against sodium. Finally, a Na-ion full-cell with the structure of NTP-rGO10-CNT10|1 M NaClO4 in PC|NVOPF@C has been fabricated. This newly designed full-cell can deliver good electrochemical performance in terms of cycleability and power.