Synthesis and electrochemical properties of non-stoichiometric Li_xM_(0.01)FePO_4

Reheological phase reaction method(RPR) was used to synthesize non-stoichiometric lithium iron phosphate(LixY0.01FePO4 and LixMo0.01FePO4).The samples were characterized by X-ray diffraction and scanning electron microscope techniques.The results show that both LixY0.01FePO4 and LixMo0.01FePO4 have the same crystal structure as that of the LiFePO4,but its cell parameters have little difference from that of LiFePO4.The electrochemical properties of both LixY0.01FePO4 and LixMo0.01FePO4 were tested by battery testing system.At a low discharging rate(0.05 C),LiFePO4 samples doping with Y and Mo have the initial discharge specific capacities of 135,130 mAh/g;Even at a higher discharging rate(0.5 C),both LixY0.01FePO4 and LixMo0.01FePO4 remain specific capacities of 108,106 mAh/g.Besides,the LixY0.01FePO4 have better electrochemical cycle performance than that of LixMo0.01FePO4.The reason for LixY0.01FePO4 and LixMo0.01FePO4 to behave good electrochemical properties as cathodes were discussed also.