X-Ray-Induced Changes to Passivation Layers of Lithium-Ion Battery Electrodes

Figure 3

Thickness estimates for the SEI calculated relative to the initial measurement of the Si 1s core excited with 4 keV photons for the peak we identified as Li_xSi (open markers) and Li_xSiO_y (solid markers). Uncertainty in these estimates, propagated from the fit areas, is less than 10% for all measurements. Energy incident on the sample from the 4 keV photon beam is estimated to be 1.5 J after 3 hours.