## 3 Applications of IL-Based Gels
### Supercapacitors
The conductivity values of the sol-gel-derived IL-based gel were close to those of corresponding IL between 20 \({}^{\circ}\)C and 100 \({}^{\circ}\)C. The glass transition temperature (Tg) of EMIMTFSI was reported to be \(-\)70 \({}^{\circ}\)C, decreasing only slightly with silica content from \(-\)88 \({}^{\circ}\)C to \(-\)90 \({}^{\circ}\)C, as shown in the DSC profile (Figure 7c). From BET isotherm (Figure 7d), the surface area of the IL-based gel was calculated to be 800 \(\pm\) 10 m\({}^{2}\) g\({}^{-1}\). The pore size distribution was about 8 nm, as obtained by the Barett-Joyner-Halenda (BJH) method. Figure 7e,f shows the cyclic voltammograms recorded for the EDLCs at 20 mV s\({}^{-1}\) after every 1000 cycles for up to 25,000 cycles at room temperature. The solid-state EDLCs displayed a super high cyclic stability, with about 92% capacity retention after 25,000 cycles. In a previous report, [PERSON]'s group showed the electrochemical performance of IL-based gel-based EDLCs with a capacitance retention of 88% after 2000 cycles, which was lower than the EDLCs reported by [PERSON] et al. [29; 119]. In 2017, [PERSON] et al. utilized an IL-based gel composed of propylene carbonate (PC) and butyltrimethylammonium bis(trifluoromethylsulfonyl)imide (N\({}_{1114}\) TSI) IL (50:50%wt) as an optimal electrolyte for symmetric MSCs based on silicon nanowire (SiNW) using a large and stable cell voltage of 3.5 V. After 3 \(\times\) 10\({}^{6}\) galvanostatic charge-discharge cycles at room temperature, the capacitance of the MSCs was reported to be 150 mF cm\({}^{-2}\)[120]. Meanwhile, in 2020, [PERSON] et al. developed and tested 3D MSCs using MnO\({}_{2}\) electrodes and a sol-gel derived IL-based gel containing PVDF in DMF and EMIMTFSI [121]. The IL-based gel-based MnO\({}_{2}\) MSC delivered excellent cycle life over 30,000 cycles. In a previous report, [PERSON]'s group described the fabrication of fluorine-modified graphene (FG)-MSCs using EMIMBF\({}_{4}\)/P(VDF-HFP) IL-based gel electrolyte, which offered a high energy density of 59 mW cm\({}^{-3}\)[122]. Table 3 summarizes some recent developments in IL-based gel-based SCs for next-generation energy storage devices. Figure 7: (**a**) TGA showing the thermal stability of the pristine IL and of the IL-based gel; (**b**) conductivity versus temperature; (**c**) DSC profiles of the IL and of the IL-based gel; (**d**) N\({}_{2}\) adsorption/desorption isotherm; inset: BJH pore size distribution for the IL-based gel after IL extraction. Galvanostatic cycling with potential limitation (GCPL) data at room temperature (**e**,**g**) and 100 \({}^{\circ}\)C (**f**,**h**) for EDLCs using IL (**a**,**b**) and IL-based gel electrolytes (**c**,**d**); insets: CV at 20 mV s\({}^{-1}\) recorded after every 1000 GCPL cycles; at the 25,000 th cycle, the charge efficiency is 78, 85, 73, and 83% for e, f, g, and h, respectively. Reprinted with permission from ref. [29]. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Scs** & **IL-Based Cel** & **Preparation Process** & **Electrodes Used** & **Lifecytes and Electrodes** & **Sublility Window** & **Specific Capacitance** & **Power and Energy Density** & **Jonic Conductivity** & **Refs.