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, LiTi 2- x Mn x (PO 4- 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.