18650 battery 3.7v 3500mah

　　Research on thermal runaway of 18650 lithium battery at 80℃

　　Inadequate thermal management of the battery during operation can cause it to heat up, entering a self-heating mode. When the temperature continues to rise uncontrollably, thermal runaway occurs, which ultimately endangers the safety of the system. When a battery is repeatedly charged/discharged or stored at high temperatures, the capacity of the battery decreases. High charge/discharge cycles for Li-ion batteries

　　Inadequate thermal management of the battery during operation can cause it to heat up, entering a self-heating mode. When the temperature continues to rise uncontrollably, thermal runaway occurs, which ultimately endangers the safety of the system. When a battery is repeatedly charged/discharged or stored at high temperatures, the capacity of the battery decreases. High charge/discharge cycle performance and high safety level of lithium-ion batteries are essential for their large-scale applications. Therefore, to meet these requirements, it is important to analyze the decay behavior of Li-ion batteries and its impact on safety.

　　Thermal runaway in lithium-ion secondary batteries can occur under various circumstances. The dependence of the state of charge (SOC) on the onset temperature of thermal runaway and areas of self-heating and thermal runaway in the battery can be identified using thermal mapping images. But only a few studies have focused on the thermal behavior of lithium battery decay. Furthermore, most discussions on their thermal properties have focused on heat yield or specific calorific value, and the correlation between these parameters has not been investigated.

　　Recently, Professor Minoru Umeda of Nagaoka Institute of Technology in Japan used 18650 LiCoO2 batteries as the research object, and stored the batteries at different SOC levels at 80°C for different lengths of time. Based on this, the author summarizes and analyzes the relationship between the thermal runaway onset temperature of the battery, the self-heating rate, and the heating rate of each battery. It was found that the self-heating rate is linearly related to the thermal runaway onset temperature, while the relative heat generation rate is exponentially related to it. The battery charged to 100% SOC exhibited the lowest onset temperature of thermal runaway. That is, the higher the energy content, the easier it is for thermal runaway to occur.