Ameliorated Li+ extraction/insertion kinetics and stability of LiMnPO4 by Al3+ doping

The effect of doping Al3+ into Li1-xAlxMnPO4 is investigated by comparing the properties of LiMnPO4 and Li0.98Al0.02MnPO4 and their delithiated phases. Through the experiment of chemical delithiation and the measurements of potentiostatic intermittent titration technique (PITT) and chronoamperometry, it is found that doping Al3+ into LiMnPO4 to obtain Li0.98Al0.02MnPO4 can accelerate the kinetics of Li+ extraction/insertion, which improves the rate capability of LiMnPO4. In addition, Fourier transform infrared spectroscopy (FTIR) and thermogravimetry-differential scanning calorimetry (TG-DSC) measurements reveal that the Al3+ doping can also effectively ameliorate the stability of the delithiated phase of LiMnPO4.