With the acceleration of the global energy transition, lithium batteries, as the main force of energy storage systems, have attracted much attention for their performance and safety. However, lithium batteries generate heat during charging and discharging, and the lack of effective heat treatment can reduce efficiency or cause the risk of thermal runaway. This article will provide an in-depth analysis of why lithium battery energy storage systems must rely on heat treatment technology.
1.The Effect of Extreme Temperatures on Lithium Batteries (1)In a high-temperature environment: The chemical reaction rate inside the lithium battery will increase exponentially, resulting in an increase in internal resistance, capacity attenuation, and even thermal runaway in serious cases, and eventually irreversible damage.
(2)In a low temperature environment: The negative electrode of a lithium battery is prone to precipitate metallic lithium during charging, which not only permanently reduces the capacity of the battery, but also may form sharp lithium dendrites that pierce the battery separator, causing an internal short circuit.
2.Effect of heat treatment on the performance of lithium batteries
(1)Boost energy efficiency Studies have shown that lithium batteries have the highest efficiency at 25°C~35°C. Through precise temperature control, the heat treatment can compress the temperature difference of the battery pack from the industry average of ±8°C to ±2°C, improving the overall system efficiency by about 15%. (2)Extended cycle life High temperatures accelerate electrolyte decomposition and SEI film deterioration. By stabilizing the operating temperature below 30°C through thermal management, the cycle life of lithium batteries can be extended from 2,000 cycles to more than 4,000 cycles (3)Protect against security risks Thermal runaway is the main cause of lithium battery accidents. Active cooling technologies, such as liquid cooling, can delay heat diffusion time by more than 20 minutes, creating a critical window for emergency response. Therefore, the thermal management design of the battery management system (BESS) needs to take into account efficiency and safety, and stabilize the operating temperature of the battery pack at about 25°C through air cooling technology, liquid cooling technology and phase change material (PCM). Whether it is to improve efficiency or ensure safety, lithium battery energy storage systems are inseparable from efficient heat treatment technology.
