화학공학소재연구정보센터
Journal of Power Sources, Vol.295, 1-8, 2015
Electrochemical properties of Li3-xNaxV2-xTix(PO4)(3)/C cathode materials in lithium ion batteries
Li3-xNaxV2-xTix(PO4)(3)/C (x = 0, 0.01, 0.03, 0.05, and 0.07) have been prepared via a conventional sal gel method. X-ray diffraction patterns indicate that Li3-xNaxV2-xlis(PO4)(3)/C are successfully obtained with a monoclinic structure. X-ray photoelectron spectroscopy has been performed to investigate the valence states of the doped elements. The morphologies of Li(3-x)NaxV(2-x)Tix(PO4)(3)/C are investigated by field emission scanning electron microscopy. Li(2.97)NaaosVi.s(7)Tioo(3)(PO4)(3)/C exhibits the highest electrochemical properties among all the samples. It delivers an initial discharge capacity of 170.61 mAh g(-1) and capacity retention of 72.66% after 100 cycles, while the uncoated Li3V2(PO4)3/C only delivers an initial discharge capacity of 164.08 mAh g(-1) and capacity retention of 71.59% in the voltage range of 3.0-4.8 V. In addition, the results of cyclic voltammetry and galvanostatic intermittent titration technique ensure that the ionic conductivity of Liz(2.97)Na(0.03)V(1.97)Ti(0.03)(PO4)(3)/C is increased compared with the uncoated Li3V2(PO4)(3)(C) 2015 Elsevier B.V. All rights reserved.