A study on chemical kinetics of carbonates-based electrolytes for enhancing fire safety in lithium-ion batteries – A review

Lithium-ion batteries are widely used in electronics and electric vehicles for their high energy storage and long lifespan. Electrolytes are a major source of lithium-ion transportation between electrodes. However, the organic components of electrolytes can also present a fire hazard. Therefore, it is essential to investigate the oxidation of electrolytes under different oxidizing environments and analyze the chemical stability of solvents, salts, and cathode materials. To understand the reactive chemistry and fire propensity of lithium-ion battery carbonate solvents, several gas phase experimental techniques such as shock tube (ST), flow reactor (FR), jet stirrer reactor (JSR), and rapid compression machine (RCM) have been used to analyze the reaction chemistry of carbonate mixtures. Flammable gases are generated during the oxidation and pyrolysis of carbonate mixtures, and the product species can be analyzed by using MBMS and GC–MS. This review describes the chemical kinetics model of various carbonate-based electrolytes under oxidation and pyrolysis conditions, providing insights from a fire safety perspective. It is recommended to employ fundamental combustion experiments for the analysis of the decomposition and oxidation processes of carbonate-based electrolytes (DEC, DMC, EMC, EC, etc.) under low-temperature and atmospheric-pressure conditions relevant to the environment of lithium-ion batteries. This review emphasizes the recent developments in carbonate base electrolyte's chemistry, thermal stability, and their implications for fire safety.