Operando Analysis of Interphase Formation in Li-ion Batteries
Presenter: Erik J. Berg
Title: Operando Analysis of Interphase Formation in Li-ion Batteries
Affiliation: Uppsala University
Prolonging the Li-ion cell lifetime is necessary to reduce cost and environmental impact of battery ownership. A significant part of the problem, but also its solution, is the solid electrolyte interphase (SEI) on the negative electrode. Although required for a functioning cell, the SEI also consumes lithium/charge and adds a Li+ diffusion resistance, which increases upon cycling. Understanding the mechanisms behind specific charge loss and electrode impedance is crucial for improved battery cells. Considering the complex dynamics of the SEI formation process, the nm-sized dimension of this interphase, as well as the intermediacy and instability of many interphase species, operando analysis methods are preferred. Operando electrochemical quartz crystal microbalance with dissipation monitoring (EQCMD) coupled with simultaneous electrochemical impedance spectroscopy (EIS) will be presented and shown to provide unique insights into the mechanical and electrochemical properties of the SEI.