Hierarchical porous carbon guided by constructing organic-inorganic interpenetrating polymer networks to facilitate performance of zinc hybrid supercapacitors

Customized design of well-defined cathode structures with abundant adsorption sites and rapid diffusion dynamics, holds great promise in filling capacity gap of carbonaceous cathodes towards high-performance Zn-ion hybrid supercapacitors (ZHC). Herein, we fabricate a series of dynamics-oriented hierarchical porous carbons derived from the unique organic-inorganic interpenetrating polymer networks. The interpenetrating polymer networks are obtained through physically knitting polyferric chloride (PFC) network into the highly crosslinked resorcinol-formaldehyde (RF) network. Instead of covalent bonding, physical interpenetrating force in such RF-PFC networks efficiently relieves the RF skeleton shrinkage upon pyrolysis. Meanwhile, the in-situ PFC network sacrifices as a structure-directing agent to suppress the macrophase separation, and correspondingly 3D hierarchical porous structure with plentiful ion-diffusion channels (pore volume of 1.35 cm3/g) is generated in the representative HPC4 via nanospace occupation and swelling effect. Further removal of Fe fillers leaves behind a large accessible specific surface area of 1550 m2/g for enhanced Zn-ion adsorption. When used as the cathode for ZHC, HPC4 demonstrates a remarkable electrochemical performance with a specific capacity of 215.1 mAh/g at 0.5 A/g and a high Zn2+ ion diffusion coefficient of 11.1×10−18 cm2/s. The ZHC device yields 117.0 Wh/kg energy output at a power density of 272.1 W/kg, coupled with good cycle lifespan (100,000 cycles@10 A/g). This work inspires innovative insights to accelerate Zn diffusion dynamics by structure elaboration towards high-capacity cathode materials.