Supporting Information for Probing Electric Double Layer Composition via in-situ Vibrational Spectroscopy and Molecular Simulations

1 Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720 United States 2 Electrochemistry Branch, Sensor and Electron Devices Directorate, Power and Energy Division, U.S. Army Research Laboratory, Adelphi, MD 20783, United States 3 Materials Science Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, United States 4 Debye Institute for Nanomaterials Science, Utrecht University, 3508 TA Utrecht, The Netherlands 5 Chemical Science Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, United States