Study on the Corrosion of Iron by Lithium-Ion Battery Fire Extinguishing Agent - Perfluorinated Hexanone

Abstract

ABSTRACT In recent years, perfluorinated hexanone has been widely used as a fire extinguishing agent for lithium-ion batteries in China. However, it can cause corrosion of ferrous materials in LIBs/batteries, such as storage tanks, battery boxes and ferrous connectors, while extinguishing LIBs fires. Therefore, when storing or using perfluorinated hexanone, it may cause secondary disasters. In order to clarify the corrosion mechanism and the structure of the products of perfluorinated hexanone on iron, we designed experiments to obtain “iron corrosion product”. Then the main components of the corrosion products were studied by various chemical analysis methods and the corrosion mechanism was proposed. The results show that the main component of “iron corrosion product” is (CF3CF2COO)3Fe, which is generated by the reaction of CF3CF2COOH, the decomposition product of perfluorinated hexanone, with iron oxides. Accordingly, it can be determined that perfluorinated hexanone has certain safety hazards when used as a lithium-ion battery fire extinguishing agent. In order to avoid the above safety hazards of perfluorinated hexanone, it is recommended that when storing and using perfluorinated hexanone, it needs to be protected from light and moisture.