Study on the Thermal Runaway of a Sport Camera Lithium-Ion Battery Associated with Instrumental Analysis of Its Components

Abstract

Action cameras are widely popular in daily life to record images of a panoramic view, fast random shooting, and extreme sports. It is regrettable that there is no academic study on the abusive risk associated with the lithium-ion batteries equipped in sports cameras. In this work, the thermal runaway (TR) phenomena of GoPro Li-ion batteries (LIB) with a stage of charge (SOC) of 0, 25, and 50% were investigated. The battery samples were tested by using an accelerated rate calorimeter (ARC) equipped with a specially customized battery holder. The internal materials of the battery were disassembled for characterization. The results show that the TR power of the GoPro LIB should not be underestimated albeit with low or medium battery capacity. During the TR course, the maximum temperature of the 50% SOC LIB can reach 470 °C, which is close to the maximum temperature limit of ARC. The maximum self-heat rate can exceed more than 1000 °C min–1. Moreover, the TR risk of the LIB increases with the high value of SOC. It is worth mentioning that the initial decomposition process of the solid electrolyte interface (SEI) was monitored, which resulted in the onset of the TR. In addition, the cathode material was determined to be LiCoO2, while that of the separator was verified to be polyethylene (PE). Microscopically, it can be found that the internal material was obviously destroyed after thermal runaway. In addition, through the thermal stability characterization and instrumental analysis of the battery’s components, it can be found that the TR is strongly related to the breakdown of the separator.