Electrochemical and magnetic characterization of LiFePO4 and Li0.95Mg0.05FePO4 cathode materials
A series of lithium iron phosphates was synthesized via the sol–gel route. Iron phosphides, which are electronic conductors, were formed when sintered at 850°C. Magnetic susceptibility measurements on the samples show antiferromagnetic behaviour with T N=50±2 K for LiFePO4 and Li0.95Mg0.05PO4 sintered at temperatures below 850°C. The LiFePO4 and Li0.95Mg0.05FePO4 cathodes show a stable electrochemical capacity in the range of 150–160 mA h/g on cycling. The cyclability deteriorates with increasing sample sintering temperature due to the increased crystal size and impurities.