Controllable synthesis of aluminium-doped LiMnPO4/C cathode materials with stable electrochemical performance for lithium-ion battery

[Display omitted] •Monodispersed spherical-shaped Li3-3xAlxPO4 precursors are innovatively prepared by a co-precipitation strategy.•A novel hydrothermal method to synthesize Al3+ ion doped Li1-3xAlxMnPO4/C cathodes are present.•The initial discharge capacity of Li0.7Al0.1MnPO4/C sample is 147.8 mAh/g at 0.05 C rate.•Li0.7Al0.1MnPO4/C shows good cycle stability and rate performance. The Al3+ ion doped Li1-3xAlxMnPO4/C cathode materials are prepared by a two-step synthetic method, the co-precipitation combined with hydrothermal routine, and the doping effects on phase structure, surface morphology and electrochemical properties are studied. XRD patterns confirm that some tiny AlPO4 impurity generates in the synthesized Al3+ ion doped Li3PO4 precursors, after the hydrothermal process a single olivine-type phase Li1-3xAlxMnPO4/C samples are prepared without impurity phase. SEM results show that the concentration of Al3+ ion has some impacts on particle diameter, the porosity and agglomeration degree of the primary particles of Al3+ ion doped Li3PO4 precursors and LiMnPO4/C samples. Among all the samples, Li0.7Al0.1MnPO4/C sample delivers the maximum discharge capacity of 147.8 mAh/g (0.05 C) and 135.7 mAh/g (1 C) for the first cycle. At 0.05 C, the capacity loss is kept at 9.9% after 200 cycles. The analysis indicate that the electrochemical performance of LiMnPO4/C cathodes have been improved by doping a certain amount of aluminium ions.