Lithium-ion Battery Integrated Use Of Performance Evaluation, Repair And Related Mechanism Study

Based on the performance of the commercial quadrate Li-ion batteries (LP063450AR, 950mAh) provided by BYD Battery Ltd. (Shenzhen, China), The feasibility of electrochemical recovery of capacity loss for lithium secondary batteries was studied. the mechanism of electrochemical recovery was characteried by X-ray diffraction, electrochemical impendance spectrum and indictive coupled plasma-atomic emission spectroscopy. The results show that the capacity loss of lithium secondary batteries with cycling can be effectively prohibited by adding the proper low current charge/discharge process. After each 50cycles, the discharge capacity increase by 40-50mA. h after recovery for the batteries cycled at 1C and 2C rate. ICP-AES result shows that the chemical formula of the positive material is Li_0.776CoO₂ and Li_0.907CoO₂ respectively before/after recovery after 300 cycles. The recovery mechanism can be attributed to enhancing the kinetics properties of batteries, thus more li-ion intercalating into the LiCoO₂ lattice and enhancing the usage of active material and the capacity properties of batteries.As one of three essential factors of Li-ion batteries, the reasonable consideration of organic electrolyte plays an important role in the enhance of comprehensive properties of lithium-ion batteries. The evaporation of organic electrolyte and varations of the effect of electrochemical recovery of lithium-ion batteries was investigated. The corresponding reason of varations of the efffect of the electrochemical recovery was also analyzed.A comparison was made between "coefficient of capacity quality" (λ) and efficiency of charge/discharge (η). there is an obvious difference between the coefficient of capacity quality and the efficiency of charge/discharge (η) served as evaluation indexes for secondary batteries. Based on the data of BYD LP063450AR Li-ion batteries, the correlation between the capacity quality and the rate capability and the cycling capability were in parallel characterized. The results reveal that the secondary battery with a good capacity quality also has a good cycling capability and rate capability, especially at high rate. The introduced capacity quality not only subtly covered kinetic information of the secondary batteries but also factually reflected stability of the introduced capacity quality not only subtly covered kinetic information of the secondary batteries but also factually reflected stability of the battery or the electrode materials.