Deep-Eutectic-Solvent-Assisted Synthesis of Hierarchical Carbon Electrodes Exhibiting Capacitance Retention at High Current Densities

An all‐in‐one solvent! Hierarchical carbon–carbon nanotube composites were synthesized by using deep eutectic solvents (DESs) as reaction media, catalyst, and structure‐directing agent. The resulting carbon monoliths exhibited a combination of high conductivity, hierarchical structure, and mechanical properties that contributed to retention of 75 % of the initial capacitance at current densities of up to 29 A g−1.