Rational design of integrated high-performance flexible zinc-ion hybrid supercapacitors based on electroactive biomass regulated graphene oxide

All-in-one zinc-ion hybrid supercapacitors constitute an indispensable part in adapting to the rapid development of flexible energy storage equipment. In this work, reduced graphene oxide/tannin (rGO/TA) complexes were used to make the flexible electrodes by vacuum assisted process. Tannin can reduce the agglomeration of reduced graphene oxide while providing additional pseudocapacitance, which leads to a large improvement in the electrochemical performance of the rGO/TA complex. At the same time, Mn2+ was added to the electrolyte to improve the energy storage capacity of Zn-ion hybrid supercapacitors (ZIHC). According to this reasonable design, the quasi-solid-state ZIHC assembled with an integrated electrode composed of rGO/TA cathode // Zn/EG anode has excellent electrochemical performance (the maximum capacity of 195.6 mAh g−1) and flexibility (the capacity is maintained at 97.3