Cyrene was used for the first time as a solvent for the fabrication of supercapacitor electrodes. This bio-derived solvent allowed the fabrication of stable surfactant-free concentrated suspensions of multiwalled carbon nanotubes (MWCNT). Cyrene was found to be a green alternative to the toxic solvents for the fabrication of polymethylmethacrylate (PMMA) binder solutions. The interaction of dissolved PMMA with Mn3O4 nanoparticles allowed for good particle dispersion and fabrication of stable suspensions in Cyrene. Advanced slurries, containing PMMA and co-dispersed MWCNT and Mn3O4 were used for the fabrication of Mn3O4-MWCNT cathodes with active mass of 36 mg cm−2. The electrodes showed high capacitance of 3.79 F cm−2 from cyclic voltammetry data and 4.15 F cm−2 from chronopotentiometry data and good cyclic stability. High capacitance was achieved at low electrode resistance. Cyrene offers advantages for the fabrication of electrodes for energy storage devices by colloidal methods. Display omitted •Cyrene was used as a solvent for the fabrication of supercapacitor electrodes.•Cyrene allowed dispersion of carbon nanotubes (CNT) at high concentrations.•Cyrene is a green solvent for polymethylmethacrylate (PMMA) binder.•Mn3O4 nanoparticles were well dispersed in PMMA solutions in Cyrene.•Mn3O4-CNT cathodes showed high capacitance and low impedance.