We utilized a standard 1010E Gamry potentiostat for electrochemical measurements in this work. Three high-purity electrodes were placed through the top channels of the BN cell such that their ends were immersed (3-5mm deep) in molten salt in the cell. We used a tungsten rod as the working electrode, a glassy carbon rod as the counter electrode, and platinum wire as quasi-reference electrode. The electrodes were separated by approximately 1.5 mm from each other inside the BN cell. The electrodes were fixed in place by an alumina fixture that the BN cell was mounted on. Figure includes photos of the BN cell with electrodes labeled.