Electrolyte-Cathode Interactions

As lithium-ion batteries evolve toward higher cell voltage and capacity, developing detailed knowledge of the electrolyte-electrode interface is critically important. The chemical composition and morphology of interphases dictate not only the reversibility (cycle or calendar life), but also the kinetics of the cell chemistry (power density), and it has been well-recognized that the complicated interplay among electrolyte components (solvent, salt anion, additive) and electrode surfaces affect interphasial properties. While there is general agreement on solid electrolyte interphase (SEI) formation on graphitic anodes, clear evidence of passivation at the cathode interface remains elusive. Primarily using in-situ electrochemical atomic force microscopy (EC-AFM) and confocal Raman spectroscopy, our studies focus on the in situ and in operando electrolyte-cathode interactions under various chemical and electrochemical environments with the goal of identifying factors that influence phenomena at the interface.