Abstract:Aluminum doped zinc oxide (AZO), as an electrically conductive material, was applied to coating on the surface of olivine-type LiFePO₄ synthesized by solid-state method. The charge-discharge test results show that the rate performance and low-temperature performance of LiFePO₄ are greatly improved by the surface treatment. Even at 20C rate, the discharge specific capacity of 100.9 mA·h/g was obtained by the AZO-coated LiFePO₄ at room temperature. At -20 °C, the discharge specific capacity at 0.2C for un-coated LiFePO₄ and the coated one are 50.3 mA·h/g and 119.4 mA·h/g, respectively. It should be attributed to the electrically conductive AZO-coating which increases the electronic conductivity of LiFePO₄. Furthermore, the surface-coating increases the tap-density of LiFePO₄. The results indicate that the AZO-coated LiFePO₄ is a good candidate of cathode material for applying in lithium power batteries.

Key words: lithium ion battery; LiFePO₄; coating; cathode material; aluminum doped zinc oxide