To examine the influence of electrode microstructure with a wider range of commercially-relevant electrolytes, cells were assembled with undiluted EMIM-BF4 (6.3 M), an ionic liquid commonly used in supercapacitors. Similar to experiments with organic electrolytes, CV experiments with EMIM-BF4 at 10 mV s -1 confirmed a stable voltage window of ca. 1 V for all Cu3(HHTP)2 samples (Fig. ), and B-CuHHTP and C-CuHHTP once again exhibited lower charge storage on this timescale. However, GCD experiments revealed notable differences in behaviour with EMIM-BF4 compared to organic electrolytes. While a specific capacitance of 57 ± 2 F g -1 was recorded for A-CuHHTP at low current densities, similar to previously reported values for related frameworks with this electrolyte, both B-CuHHTP and C-CuHHTP displayed significantly lower specific capacitances of 8 ± 2 and 3 ± 1 F g -1 , respectively (Fig. ). This is in contrast to the performance with organic electrolytes, where both A-CuHHTP and B-CuHHTP exhibited similar specific capacitances at low current densities. To determine if this was a kinetic effect, cells were charged at a very low current density of 0.0025 A g -1 to allow additional time for ionic diffusion and exchange (SI Fig. , Table ). Once more, the specific