Impact of high-temperature environment on the optimal cycle rate of lithium-ion battery

Considering the complexity of working environment and the sensitivity of lithium-ion batteries, a series of experiments are performed in the present work to investigate the impact of high-temperature environment on the optimal cycle rate of lithium-ion batteries. Two ambient temperatures (26 and 70 degrees C) and four cycle rates (0.5 C, 1 C, 2 C and 3 C) are involved. It is revealed that a high or low cycle rate would aggravate battery degradation under both normal and high temperature environment; in the end, an optimal cycle rate is obtained at 2 C under the coupled effects of degradation rate and cycle duration. In comparison with the normal-temperature environment, it is interesting to find that the high-temperature environment may be beneficial to the high-rate cycling. Besides that, the degradation behaviors are further demonstrated through the evolution of delta V, charge/discharge voltage, surface temperature and internal resistance.