| In this paper, we used LiFePO4 as cathode active material and Li plate as anode active material to prepare button batteries. This paper studied the density of plate, compacted density of plate and changing of current collectors surface, the effects of cathode preparation like Ketjenblack(KB) application and charging/discharging system like activation system, the voltage of charging/discharging system on the performance of Li-ion batteries, also optimized the preparation parameters and charging/discharging system. The results showed that in the LiFePO4 cathode preparation process, density and compacted density of plates had effect on the performance of Li-ion batteries,when density of 1.565 mg/cm2, compacted density of 0.778 g/cm3, Li-ion batteries can get better electrochemical performance. After the roughness of current collectors surface was treatmented, the adhesion of coating cathode surface was improved, and the contact resistance was done lower so that the specific capacity was improved by 8.8% after 10 cycles. High speed shear can improve the dispersion of KB in LiFePO4 battery slurry, obtain a plate of good conductive network structure and good adhesion, a better electrochemical performance was obtained with KB conductive(the first charge and discharge capacity increased by 7.8%, charge transfer resistance decreased by 12.5%). Charging/discharging system had great effect on the performace of Li-ion batteries, it can decrease the activation time and keep normal specific capacity with 0.2C rate. Within a certain range of charge and discharge rate, discharge capacity of lithium-ion battery was strong connected with discharge current rate.
|
PDF Full Text Request