Characteristics and electrochemical performance of LiFe _0.5Mn _0.5PO ₄/C used as cathode for aqueous rechargeable lithium battery

LiFe _0.5Mn _0.5PO ₄/C cathode materials are synthesized by a sol-gel method and the precursor calcinations. The phase structures and morphologies are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Galvanostatic charging/discharging cycles of as-prepared LiFe _0.5Mn _0.5PO ₄/C are performed in the saturated LiNO ₃ aqueous solution. The initial discharge capacities of (LiFe _0.5Mn _0.5PO ₄/C)//LiV ₃O ₈ aqueous rechargeable lithium battery are 123.09 mAh g ^-1 and 107.00 mAh g ^-1 at 0.05 C and 0.1 C, respectively. And it delivers a capacity of 66.77 mAh g ^-1 at 50 C which is greater than that of 20 C and 30 C, exhibiting good cycling performance at 50 C. This is the first report of a successful utilization of LiFe _0.5Mn _0.5PO ₄/C as cathode material for ARLB and the lithium-ion diffusion coefficients of the LiFe _0.5Mn _0.5PO ₄/C are calculated from the cyclic voltammetry data.