Online Electrochemical Mass Spectrometer (OEMS): A Smart Pathologist for Batteries

Online Electrochemical Mass spectrometry (OEMS) is a very important tool for in-operando detection of evolved gases as a function of applied potential on the real-time scale. In-Operando gaseous evolution studies are very important to know the battery health and the reasons behind its failure. We herein, show with examples that OEMS analysis can give a deep insight into the reactions happening inside the battery. It can be used to trace onset potential for parasitic reactions like electrolyte degradation, electrode corrosion and thus can help in optimizing the working conditions and interfacial protection strategies. Using the OEMS studies, the reaction products like HF, POF 3 , CO 2 , O 2 etc. can be analyzed even in trace quantities.