Improving the cycling stability and rate capability of LiMn_(0.5)Fe_(0.5)PO_(4)/C nanorod as cathode materials by LiAlO_(2) modification

LiMn_(0.5)Fe_(0.5)PO_(4)(LMFP)@C and LMFP@LiAlO_(2)@C nanorods are successfully synthesized by a solvothermal process followed by a calcination at H2/Ar atmosphere.The carbon coating and LiAlO_(2) coating does not change the morphology and particle size of LMFP,and all samples show nanorod morphology with 50-100 nm in width and 200-300 nm in length.The results show that LiAlO_(2) coating can offer rapid charge transfer channels with improved intercalation/de-intercalation kinetics of Li ions,which make an outstanding rate capability and cycling stability of as-synthesized LMFP@LiAlO_(2)@C cathodes.As a result,LiAlO_(2) coating effectively improves the rate capability and cycling stability of LMFP cathode even at high discharge rates.Hence,LMFP@LiAlO_(2)(5 wt%)@C indicates an outstanding rate performance with a reversible discharge capacity of 137.6 and 113.2 mAh g^(-1) discharged at 0.05 C and 5 C rates,and the composite also shows a good cycle performance with an excellent capacity of 107 mAh g^(-1) and 86.4% capacity retention rate at 5 C rate after 100 cycles.Therefore,the LiAlO_(2) coating can be considered as an effective way to improve the electrochemical properties of LMFP.