Study on the modifying of LiFePO_4 by Ni doping

Li-ion battery cathode materials LiFe_(1-x)Ni_xPO_4(x=0,0.05,0.10,0.20,0.30,0.40 and 0.50)were synthesized by the solid state reaction.The crystal parameters of LiFePO_4 were changed with the partial substitution of Ni for Fe,the continuous solid solution of LiFe_(1-x)Ni_xPO_4 was obtained.The particle size was reduced after doping.The initial discharge capacity of LiFe_(0.90)Ni_(0.10)PO_4 at low rate(0.1 C) was biggest(140 mAh/g),increased 12% than that of LiFePO_4.Its discharge capacity(114 mAh/g) was increased 32% than that of LiFePO_4 with the discharge rate of 0.5 C.Little Ni doping increased the discharge capacity of LiFePO_4 and improved the charge/discharge capacity at high rate.