Under extremely low temperature conditions (below −20°C), due to the increase in the viscosity of the electrolyte, the diffusion rate of Li-ions in the electrolyte was severely reduced and the internal resistance of the battery increased sharply, which inevitably led to a substantial decrease in the power supply/absorption capacity .
Wu, X., Chen, Z., Wang, Z.: Analysis of low temperature preheating effect based on battery temperature-rise model. Energies 10, 1121 (2017) Ruan, H., Jiang, J., Sun, B., et al.: An optimal internal-heating strategy for lithium-ion batteries at low temperature considering both heating time and lifetime reduction. Appl. Energy. 256, 113797 (2019)
The impact of low temperatures on Li-ion batteries is multifaceted, affecting their lifespan , power and energy capacity , round trip efficiency , and charge acceptance .
In contrast, batteries may experience accelerated chemical reactions at high temperatures, including undesired side reactions. The excessive heat generated at high temperatures can degrade the battery's performance and lead to safety risks, including thermal runaway.
LIBs as a complicated electrochemical energy storage system will produce a lot of heat during the operating process, especially on high rate charge/discharge processes [17, 18]. In Zhang’s study, the temperature of a NMC battery will exceed 75 °C at a 3 °C discharging rate without any treatment (ambient temperature is 25 °C) .
Also, temperature uniformity is crucial for efficient and safe battery thermal management. Temperature variations can lead to performance issues, reduced lifespan, and even safety risks such as thermal runaway. Uniformity in temperatures within battery thermal management systems is crucial for several reasons: 1.