Journal of Power Sources, Vol.251, 325-330, 2014
Nanosized LiVPO4F/graphene composite: A promising anode material for lithium ion batteries
This study first reports the synthesis of the nanosized LiVPO4F/graphene composite (LVPF/G). The LVPF/G composite is prepared by a facile mechanochemical approach. XRD results reveal that the prepared composite are well crystallized with triclinic LiVPO4F. SEM and TEM images demonstrate that the LiVPO4F nanoparticles in the composite are well enwrapped by graphene. Used as anode material for lithium ion batteries, the prepared LVPF/G composite exhibits greatly improved electrochemical performance. Furthermore, the electrochemical properties the LVPF/G composite depend heavily on the discharge cutoff potential. When the cut-off potential is altered to 0.01 V vs. Li/Li+, it possesses the best electrochemical performance. Under such optimal charge-discharge condition (3-0.01 V vs. Li/Li+), it shows an initial charge capacity of 287 mAh g(-1) at 0.1C rate (1C = 310 mA g(-1)) and shows no capacity fading after 100 cycles. It also exhibits good rate capability, delivering about 168 mAh g(-1) at 10C rate. (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Lithium vanadium fluorophosphate;Graphene;Composite;Anode material;Lithium ion battery;Cut-off potential