Interfacial Studies of Li-Ion Battery Cathodes Using In Situ Electrochemical Quartz Microbalance with Dissipation

In situ Electrochemical Quartz Microbalance with Dissipation (EQCM-D) was employed to investigate the initial stage of solid electrolyte interphase (SEI) layer formation on bare aluminum electrodes and cathode-coated Al electrodes for lithium-ion battery (LIB) applications. EQCM reveals the SEI layer forms spontaneously upon exposure of the electrode to battery electrolyte on both surfaces. The mass of SEI layer then increases as a function of applied voltage. EQCM-D studies demonstrate a correlation between interfacial reactions and high voltage cycling on the cathode surface. In this work, EQCM-D has been applied to LIBs for the first time, and can ultimately provide a wealth of information about the properties of SEI films on electrodes.