Perspective Chapter: Thermal Runaway in Lithium-Ion Batteries

Lithium-ion batteries (LIBs) are becoming well established as a key component in the integration of renewable energies and in the development of electric vehicles. Nevertheless, they have a narrow safe operating area with regard to the voltage and temperature conditions at which these batteries can work. Outside this area, a series of chemical reactions take place that can lead to component degradation, reduced performance and even self-destruction. The phenomenon consisting of the sudden failure of an LIB, causing an abrupt temperature increase, is known as thermal runaway (TR) and is considered to be the most dangerous event that can occur in LIBs. Therefore, the safety of LIBs is one of the obstacles that this technology must overcome in order to continue to develop and become well established for uses in all types of applications. This chapter presents a detailed study of the general issues surrounding this phenomenon. The origin of the problem is identified, the causes are detailed as well as the phases prior to TR. An analysis is made of the most relevant factors influencing this phenomenon, and details are provided of detection, prevention and mitigation measures that could either prevent the TR or reduce the consequences.