Combining structural and chemical information towards quantitative phase analysis of SEI in silicon battery anodes

We aim to identify crystalline and amorphous phases in samples of solid-electrolyte interphase (SEI) collected from silicon battery anodes at different stages of lithiation and delithiation. The SEI is regarded as one of the most important but least understood components of Li-ion batteries in view of its complex dynamic behaviour and its effect on battery capacity and stability. The combination of X-ray Raman Scattering (XRS) and X-ray diffraction coupled with Pair Distribution Function analysis (XRD/PDF) is particularly apt to resolve the composition of SEI samples as it gives complementary chemical and structural insight, and thus address key points such as formation mechanism, reactivity, and transport properties.