Flexible, all-solid-state 1.4 V symmetric supercapacitors with high energy density based on comb polymer electrolyte and 1D hierarchical carbon nanotube electrode

A high-performance solid-state supercapacitor (ssSC) based on an amphiphilic comb polymer (CP) solid electrolyte and an electrode comprising porous one-dimensional (1D) hierarchical carbon nanotubes is reported. The solid electrolyte is prepared from the amphiphilic CP, poly(vinylidene fluoride-co-chlorotrifluoroethylene)-g-poly(oxyethylene methacrylate) (P(VDF-co-CTFE)-g-POEM) comprising hydrophobic P(VDF-co-CTFE) main chains and hydrophilic POEM side chains, which provide good mechanical strength and high ionic conductivity, respectively. Preferential interaction of POEM with the ionic liquid (IL) and microphase-separated structures of CP/IL electrolytes are demonstrated. Two types of 1D hierarchical carbon nanotubes are prepared by a metal–organic-framework-derived approach using 1D tellurium as the template. The ssSC fabricated with the CP electrolyte displays a high specific capacitance of 239.3 F g⁻¹, which is much higher than that achieved with the widely used conventional poly(vinyl alcohol) electrolytes. The flexible ssSC fabricated with carbon cloth as electrode substrate exhibits a remarkable specific capacitance of 220.8 F g⁻¹.