High voltage electrochemical capacitors operating at elevated temperature based on 1,1-dimethylpyrrolidinium tetrafluoroborate

γ‐Valerolactone as Sustainable and Low‐Toxic Solvent for Electrical Double Layer Capacitors

“…Over the whole current density range from 0.5–20 A g −1 , the EDLC containing 0.6 m Et 4 NBF 4 in GVL is the one delivering the best performance, and at 10 A g −1 it delivers a specific energy and power of 15 Wh kg −1 and 23 kW kg −1 , respectively. These values are comparable to those observed for lab‐scale AC‐based EDLCs containing ACN‐ and PC‐based electrolytes [18,20] …”

“…As already discussed in our previous work, the lower stability observed on these experiments (compared to those reported above in Figure 4) is due to the used cell setup. Nevertheless, this latter modified cell setup is designed to investigate the electrolyte degradation, as it allows its extraction and its post‐mortem analysis [18] . Figure 6a compares the total ion chromatograms of 0.6 m Et 4 NBF 4 in GVL after 150 h floating at 2.7 and 2.9 V with respect to the solvent GVL.…”

“…At the end of the float tests, the cell was opened in an argon‐filled glovebox, and 300 μL electrolyte was extracted. The extracted electrolyte was then investigated by carrying out post‐mortem GC‐MS analysis, following the same procedure reported in the literature [18] . The post‐mortem GC‐MS measurements were carried out utilizing an Agilent 7890B GC, equipped with an Agilent 7683 Series ALS, and an Agilent 5977 A MS (EI‐MSD, single quadrupole).…”

Investigation of protic ionic liquid electrolytes for porous RuO2 micro-supercapacitors

“…For instance, while pyrrolidinium or alkyl ammonium-based PILs can provide a wide stability window, the PIL composed of pyridine-based cation and trifluoroacetic acid anion can render high ionicity due to their large pKa difference [35,38,41,43]. Our next goal was to determine the electrochemical window of RuO2 MSC in these electrolytes.…”

Caesium Acetate‐Based Electrolytes for Aqueous Electrical Double Layer Capacitors

“…It is important to remark that these values are much higher than those observed on imide based WiSEs, e. g. 21 m LiTFSI (8 mS cm À 1 ), [24] on acetate-based WiSE based, e. g. 27 m CH 3 COOK in H 2 O (31.4 mS cm À 1 ), [33] and organic electrolytes. [34] Although both electrolytes are highly concentrated, they display a rather low viscosity, as shown in Figure 1b, at 20 °C the electrolyte 6.4 m CsOAc in H 2 O displays a viscosity of 2.5 mPa s, while the viscosity of 21 m CsOAc in H 2 O is equal to 9.4 mPa s. The viscosity of this latter electrolyte is obviously higher due to the high salt concentration, but it is still lower to that of many WiSEs reported in literature. [35] Figure 1c is comparing the density of the two electrolytes between 0 to 80 °C.…”