NaTi2(PO4)3/Carbon and NaTi2(PO4)3/Graphite Composites as Anode Materials for Aqueous Rechargeable Na-ion Batteries

Abstract

NaTi2(PO4)3/carbon and NaTi2(PO4)3/graphite composites as anode materials for aqueous rechargeable Na-ion batteries were synthesized by modified Pechini method and pyrolysis treatment in the inert atmosphere. The structures and carbon contents of the samples were characterized by X-ray diffraction, Scanning Electron Microscopy and carbon-sulfur analyzer respectively. Electrochemical properties were evaluated by galvanostatic discharge/charge test and cyclic voltammetry using a three-electrode system. The first discharge specific capacity of NaTi2(PO4)3/carbon composites was 128.6mAhg-1 and maintained 117.4mAhg-1 after 50 cycles at a discharge rate of 2C. The reversible capacity of the composites remained 66.2mAhg-1 even at 20C. NaTi2(PO4)3/carbon composites exhibited better electrochemical performance than NaTi2(PO4)3 and NaTi2(PO4)3/graphite samples.