Synthesis and characterization of LiFePO4/C composite
used as lithium storage electrodes①
used as lithium storage electrodes①
(1. College of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China;
2. Institute of Material and Chemical Engineering,
China University of Geosciences, Wuhan 430074, China)
Central South University, Changsha 410083, China;
2. Institute of Material and Chemical Engineering,
China University of Geosciences, Wuhan 430074, China)
Abstract: LiFePO4/C composites with good rate capability and high energy density were prepared by adding sugar to the synthetic precursor. A significant improvement in electrode performance was achieved. The resulting carbon contents in the sample 1 and sample 2 are 3.06% and 4.95%(mass fraction), respectively. It is believed that the synthesis of LiFePO4with sugar added before heating is a good method because the synthesized particles having uniform small size are covered by carbon. The performance of the cathodes was evaluated using coin cells. The samples were characterized by X-ray diffraction and scanning electron microscope observation. The addition of carbon limits the particles size growth and enables high electron conductivity. The LiFePO4/C composites show very good electrochemical performance delivering about 142 mAh/g specific capacity when being cycled at the C/10 rate. The capacity fade upon cycling is very small.
Key words: Li-ion battery; positive material; lithium iron phosphate; carbon-coated