Effects of Coating Carbon Aluminum Foil on the Battery Performance

The LiFePO4-based battery properties were studied by using aluminum foil current collector coated with a conductive carbon film.The main properties of LiFePO4type battery with 10 Ah capacity were also compared by using common aluminum foil and coating carbon aluminum foil(CCAF) from different providers.The results showed that the using of CCAF current collector not only can improve the cohesiveness between the cathode powder and the current collector but can effectively reduce the contact resistance of the cathode material and the current collector,so as to reduce the direct current resistance(DCR) of the battery,and improve the rate performance of the battery.Compared with using common aluminum foil,the DCR is reduced by about 65% with using the CCAF as current collector.But the specific discharge capacity of cathode material is reduced by 5~10 mAh·g-1.And the 1stefficiency is also reduced by 4%;At large discharge rate of 15C rate,the discharge capacity of the cell with using CCAF is more than about 15% in contrast to the cell with common aluminum foil as a current collector.And at 10C discharge rate,the voltage plateau increased by 0.3 ~0.4 V with CCAF;But the self-discharge ratio of cell with CCAF is higher at room temperature,and its recovery rate of the capacity is also higher;After 500 cycles,the cyclic capability of the cell with using CCAF can increase by about 2% in contrast to the cell with the common aluminum foil as current collector.But the discharge property at low temperature is not improved by the use of CCAF as current collector.