Nitrogen-doped hollow carbon nanoboxes in zwitterionic polymer hydrogel electrolyte for superior quasi-solid-state zinc-ion hybrid supercapacitors

A superior quasi-solid-state Zn-ion hybrid supercapacitor is rationally developed using a well-engineered hollow carbon cathode material with desirable Zn 2+ storage and hydrogel electrolyte with high conductivity and dendrite-inhibition ability.