Comparison of pressure evolution in supercapacitor devices using different aprotic solvents

Gas evolution and associated pressure build up in supercapacitor devices was monitored using commercial electrode rolls and 1 mol/l solutions of TEABF4 in acetonitrile (AN), propylene carbonate (PC), and γ-butyrolactone (GBL). During subsequent constant voltage periods (24 h) at 2.5 V, 2.75 V, 3.0 V and 3.25 V, significant gas evolution was observed in GBL already at 2.5 V. Under the same conditions, severe gas evolution in PC started only at 3.0 V, while in AN rate of gas evolution remained low even at 3.25 V.