Energy Solutions CR2032 SS316 coin cell cases. Film electrodes were cut from freestanding composite f-CMK-3, f-YP-80F, f-BP-1300, and YP-80F films with areal mass loadings of functionalized carbons ranging between 5 -11 mg cm -2 . The minimum weight ratio between the negative (functionalized) and positive (YP-80F) electrodes was 1: >2.0, respectively. This ensured excess charging capacity on the YP-80F electrode (relative to the functionalized electrode). Therefore, the potential on the working functionalized electrode is expected to limit the stable working voltage range for the cell. Whatman glass microfiber filter (GF/A) was used as a separator and dried in vacuo at 100 °C for 24 h prior to use. 1-Butyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide ionic liquid (200 𝜇 L) was used as the electrolyte in all experiments. Electrochemical cells were assembled inside a glovebox under an inert nitrogen (N2) atmosphere (typical levels < 1 ppm H2O, < 1 ppm O2). Each coin cell contained two SS316 spacer disks and one SS316 spring to ensure sufficient and consistent pressure in the cells.