Evolution of the Surface and Subsurface Chemical Environment of LixNi0.8Co0.15Al0.5O2 electrodes
Here we report on our studies of the surface and subsurface of NCA electrodes with and without a binder additive (i.e. PVDF) as a function of initial charging and cycling. The chemical composition and transition metal oxidation states were determined from a combination of x-ray photoelectron and absorption spectroscopy techniques. Our results reveal dramatic differences in the surface environments between our NCA electrodes with and without binder. Our results suggest that the PVDF may play a more significant role in degrading the surface of the NCA i.e. oxygen loss, than previously thought. We also report our surface analysis of our extended cycled NCA binder free electrodes. This work was supported as part of NECCES, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001294.