Journal of Power Sources, Vol.320, 94-103, 2016
Surface-disordered and oxygen-deficient LiTi2-xMnx(PO4-y)(3) nanoparticles for enhanced lithium-ion storage
Disordered surface of anode materials accompanied by oxygen vacancies, has been developed as an efficient strategy to promote their charge-transfer kinetics and then improve their electrochemical properties. It is rarely explored for cathode materials before. Here, LiTi2-xMnx(PO4-y)(3) nanoparticles with a disordered surface and oxygen vacancies, are synthesized by a hydrothermal method following with an annealing in Ar/H-2. Their disordered surface and heteroatom doping by reduced Mn/Ti species, have been supported by HRTEM images, XPS and EDS spectra. After 120 cycles at 0.2 C, these nanoparticles still deliver a capacity of 127 mAh g(-1), much higher than the product without any doping, and that without a disordered surface. Even after 500 cycles, the capacity is still at 101 mAh g(-1) for 5 C or at 71 mAh g(-1) for 20 C. These results could be attributed to the reduced charge-transfer resistance caused by disordered surface, and the enhanced lithium-diffusion induced by doping. (C) 2016 Elsevier B.V. All rights reserved.