Promoting the performances of NaTi2(PO4)3@C porous composite as novel anode materials for application in sodium ion battery

Rechargeable aqueous sodium-ion batteries (SIBs) are urgently pursued as a low-cost candidate for grid-scale storage of intermittent renewable energies. NASICON-type NaTi2(PO4)3 holds great promises as anode material for aqueous SIBs owing to the high theoretical capacity and low redox potential, but being severely challenged by poor cycling performance and low reaction kinetics. In this study, a porous carbon-decorated NaTi2(PO4)3 composite was made using a simple sol-gel method and then thermally treated. The NaTi2(PO4)3 particles are adhered to the surface of carbon sheets uniformly. The [email protected] electrode delivers a reversible capacity of 198.1 mAhg−1 at 0.2 C, which is much higher than NTP (125.5 mAhg−1). Atta 50 cycle, a capacity of 196.5 mAhg−1 can be obtained for the [email protected] composite, which in about 99.1% of its initial capacity. From the EIS, RCT value of [email protected] was estimated to be 51.32 Ὠ which is lower than that of bar NTP (78.2 Ὠ). Carbon greatly improves the cell's performance, particularly the cycle lifetime at high charge-discharge rates of NTP electrodes. The increased structural stability and electron/Na + ion transfer kinetics of the [email protected] anode material are responsible for its exceptional electrochemical properties and long cycle lifespan.