Fig. 5
Dissolution and half-cell tests of CuHCF in co-solvent electrolyte. a The UV-vis spectra of aliquots of water and the 90% MeCN + 10% water cosolvent electrolyte, in which a CuHCF electrode was stored at room temperature for at least 48 h. A 10 p.p.m. K3Fe(CN)6 standard sample is measured for comparison. The peak at 420 nm corresponds to the dissolved Fe(CN)63–. No dissolution is observed for the co-solvent electrolyte. b The reaction potential profile of the CuHCF cathode at a 1C rate with the co-solvent electrolyte. c The cycle life and coulombic efficiency of the CuHCF electrode during 1C–1C cycling between 0.6 and 1.15 V over 6 months. The noise is due to the precipitation of salt in the Ag/AgCl reference electrode frit, resulting in an inconsistent junction potential between the reference electrode-filling solution and the electrolyte
