With the development and utilization of renewable energy, lithium-ion (Li-ion) batteries has been regarded as one of the most important energy storage technologies by virtue of their high energy density, long cycle life and low self-discharge. However, the frequent occurrence of fire or explosion caused by thermal runaway of lithium-ion batteries makes it urgent to improve their safety performance. Because of the battery external abuse, Li-ion batteries thermal runaway occurs, resulting in the growth of lithium dendrites inside the battery which will cause short circuits, electrode decomposition and gas precipitation, flammable electrolyte decomposition, leading to combustion and explosion. With the internal components of Li-ion batteries as a starting point, based on the study of the thermal runaway mechanism of Li-ion batteries, this paper made a detailed analysis on the thermal runaway triggers in terms of the positive and negative electrodes and Li-ion battery electrolyte; It also elaborated the reaction processes, within the batteries during the thermal runaway in a comprehensive way; For the thermal runway of Li-ion battery, the author proposed internal improvement strategies such as inhibiting the growth of lithium dendrites, designing electrolyte, reducing the release of positive oxygen and optimizing the diaphragm. Integrated with the external thermal management of the batteries, it will realize dual protection both inside and outside of the Li-ion batteries.

lithium-ion batteries  /  battery components  /  battery packs  /  thermal runaway  /  thermal management