Study on topographic, electrochemical, and safety characteristics of lithium-ion cells after long-term storage at abusive-temperature environments

Three types of cell samples (fresh cell, 60°C stored cell, and −10°C stored cell) were prepared to demonstrate the impact of abusive-temperature storage on the topographic, electrochemical, and safety characteristics of lithium-ion cells; besides that, the sensitivity of the three cell samples to typical abusive conditions is also discussed. In comparison to the fresh cell, the discharge capability of the cell after the storage is suppressed especially for the 60°C stored one. Meanwhile, it is found that the degradation behavior of the cell after the storage is greatly restrained during the long-term cycling. The decrease of energy storage and the thickening of passivation layers improve the thermal stability of the stored cell in the over-heating test. Moreover, the cell after storage also demonstrates better performance when exposed to abusive conditions involving high-temperature cycling and overcharge cycling than the fresh cell. Thereby, it is speculated that the abusive-temperature storage is helpful to prolong cell lives and improving the resistivity of cells to typical abusive conditions. Suitable storage before using might be considered to enhance the electrochemical and safety performance of cells.