Does the age of a lithium battery affect its thermal stability?

Chemical Degradation Process

Lithium-ion batteries (LIBs) contain multiple components, including electrodes, electrolytes, and separators, which interact with each other to facilitate chemical reactions. Over time, these interactions lead to degradation, compromising the thermal stability of the battery. Specifically, the formation of solid-electrolyte interphase (SEI) on the anode surface and the degradation of the electrolyte contribute to reduced performance and increased risk of thermal runaway.

Thermal Runaway and Self-Heating

Thermal runaway occurs when a battery overheats due to excessive temperature, causing a chain reaction of chemical reactions that accelerate heat generation. This process can lead to catastrophic failure, resulting in fire or explosion. Self-heating occurs when a battery generates heat internally, often due to internal shorts or overcharging. As a battery ages, its ability to dissipate heat is compromised, increasing the risk of thermal runaway.

Impact of Age on Thermal Stability

Studies have shown that lithium-ion batteries experience significant degradation after 300-500 charge cycles or 2-3 years of storage. At this point, the battery’s thermal stability is significantly compromised, increasing the risk of thermal runaway. To mitigate this risk, it’s essential to monitor battery health and replace batteries before they reach this critical point. Regular maintenance, such as checking for signs of physical damage or corrosion, and storing batteries in a cool, dry environment can help prolong their lifespan and maintain thermal stability.