The harmful effects of high temperatures on lithium-ion batteries
High temperatures can reduce the capacity of lithium-ion batteries, a factor that affects all types of devices, even smartphones. Operating programs can also cause them to heat up; laptops, for example, get very hot when under heavy load. Laptop batteries are generally close to electronic components, and overheating of these components during heavy workloads can damage the battery.
Increased temperature leads to instability within lithium-ion batteries, further increasing the risk of internal short circuits and damage to any nearby components. This only occurs in lithium-ion batteries without internal support. However, in lithium-ion batteries with internal copper supports, heating above 250 degrees Celsius causes the battery core to collapse, melting the copper supports and raising the internal temperature above 1000 degrees Celsius. The heat then rapidly dissipates outward, causing thermal runaway.
Lithium-ion batteries have an explosion-proof valve engraved on them. At high temperatures, the internal pressure of the battery becomes excessive, and the explosion-proof valve comes into play. First, the valve opens to release the pressure. Battery safety testing also involves high-temperature processes, such as 150-degree hot chambers, 800-degree iron plates, and high-temperature ejection, with the battery considered合格 (qualified) if it does not explode.
Under normal use, lithium-ion batteries do not reach temperatures of 250 degrees Celsius. However, the tests they conducted clarified the environment and conditions under which lithium-ion batteries explode and burn, and they hope to help manufacturers improve the safety of lithium-ion batteries in the future.
The safety of lithium-ion batteries has recently received widespread attention. Lithium-ion batteries generate heat during use. If the battery continues to heat up, it may cause an internal short circuit, crack the battery casing, and lead to accidents such as leakage and fire.
High temperatures can also cause a significant drop in battery performance. Experiments have shown that even without charging or discharging, lithium-ion batteries placed in an environment above 45°C will experience an irreversible capacity loss of 30% after six months. Therefore, high-temperature protection for lithium-ion batteries is essential.
