Abstract
Interfaces play a key role in today's lithium-ion batteries, and in tomorrow's post lithium-ion batteries. A Li-ion battery is based on the principle of a reversible exchange of electrons and lithium ions between two electrodes, separated by an electrolyte. Correct operation of the battery depends on the intrinsic properties of the active materials making up the electrodes. However, an excellent electrode material will only be truly functional if its interface with the electrolyte is well controlled. Electrode/electrolyte interfaces are therefore just as important as electrode materials, and given their complexity, this justifies a major research effort to understand the phenomena involved.
Among the various experimental methods available for studying interfaces, those that are both surface-sensitive and provide chemical information are of prime importance. Among these, X-ray photoelectron spectroscopy (XPS) has led to a number of breakthroughs, and is now essential for the development of tomorrow's batteries.
In this presentation, I show what this technique has enabled us to understand about electrode/electrolyte interfaces in lithium-ion batteries. I have also presented what it can contribute to understanding interfaces in the " post lithium-ion " systems studied today, in particular the all-solid state battery and lithium-sulfur batteries.
