High temperatures significantly degrade electric vehicle (EV) batteries by accelerating chemical reactions within the battery cells. Here are the key factors involved in this degradation process:
- Acceleration of Chemical Reactions: High temperatures increase the rate of both desired and unwanted chemical reactions inside the battery. Unwanted reactions can lead to a loss of battery life by degrading the battery’s components.
- Solid Electrolyte Interphase (SEI) Growth: The protective layer around the anode, known as the SEI, is crucial for battery longevity. At high temperatures, this layer can grow excessively, consuming active lithium and hindering ion movement. This process is part of “calendar aging,” which occurs regardless of the battery’s use.
- Creation of Inert Compounds: Excessive heat can lead to the formation of inert compounds that impede the flow of ions within the battery. This not only reduces the battery’s efficiency but also contributes to an increase in internal resistance, further accelerating degradation.
- Increased Impedance: The increased speed of chemical reactions and diffusion at high temperatures can result in higher impedance. This means that the battery becomes less efficient at conducting electrical current, contributing to reduced performance and faster aging.
- Temperature Threshold: The generally accepted temperature at which battery degradation accelerates is around 30°C (86°F). Above this threshold, the risk of rapid degradation increases significantly.
To mitigate these effects, it’s important to keep EVs in moderate temperature conditions and use thermal management systems to regulate battery temperature, especially during charging and operation.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-high-temperature-specifically-degrade-ev-batteries/
