Differences in the deterioration behaviors of fast-charged lithium-ion batteries at high and low temperatures

Demand for stationary storage batteries, which store electricity generated by natural energy, such as solar energy, is increasing. These Li-ion batteries (LIBs) may be used outside their safe temperature ranges, depending on the usage environment, and they are required to charge as rapidly as possible when used frequently. Therefore, the cycle deterioration behaviors of LIBs at different operating temperatures at high rates of charge are studied here. Compared with the deterioration at high temperatures, the decrease in battery capacity at low temperatures is higher, and more severe deterioration is observed at temperatures that differ considerably from the safe temperature range. Based on differential capacity analysis, the peaks corresponding to the anode are significantly reduced at the potential of the initial charging stage after cycle deterioration at low temperatures. Therefore, the number of Li ions intercalated into/deintercalated from the graphite layer decreases. The activation energies of deterioration confirm that the mechanisms of battery deterioration differ at high and low temperatures, based on the negative and positive values obtained at low and high temperatures, respectively. Overall, deterioration at high temperatures affects the cathode, and that at low temperatures affects the anode.