Highly Stable Dispersion of Carbon Nanotubes in Deep Eutectic Solvent for the Preparation of CNT-Embedded Carbon Xerogels for Supercapacitors

The current study reports a kind of ternary deep eutectic solvent (DES) based on choline chloride, urea, and glycerol for the dispersion of multi-walled carbon nanotubes (MWCNT) in the presence of surfactant. MWCNT-embedded organic gels were subsequently prepared from the polymerization of resorcinol and formaldehyde in the obtained MWCNT-dispersed DES. It has been demonstrated that the as-prepared DES is excellent in dispersing and stabilizing the MWCNT, and thus allows the in situ synthesis of MWCNT functionalized resorcinol-formaldehyde xerogels with no visible phase-separation during the long sol-gel process. After ambient drying and carbonization, MWCNTs can be well dispersed within the carbon xerogel matrix. The obtained carbon material possesses increased electrical conductivity while preserves the well-developed porous structure. When used as electrodes in supercapacitors, it exhibits enhanced capacitance as well as rate performance. The specific capacitance at 0.5 A g(-1) was 228 F g(-1), 22 % more capacitance than that of the pristine carbon xerogel. More remarkably, it provides the electrodes with more than 200 % enhancement in capacitance when compared with that of the MWCNT-embedded carbon xerogel prepared in aqueous solvent under the same conditions.