Kinetics process for structure-engineered integrated gradient porous paper-based supercapacitors with boosted electrochemical performance

Due to their rich and adjustable porous network structure, paper-based functional materials have become a research hotspot in the field of energy storage. However, reasonably designing and making full use of the rich pore structure of paper-based materials to improve the electrochemical performance of paper-based energy storage devices still faces many challenges. Herein, we propose a structure engineering technique to develop a conductive integrated gradient porous paper-based (CIGPP) supercapacitor, and the kinetics process for the influence of gradient holes on the electrochemical performance of the CIGPP is investigated through experimental tests and COMSOL simulations. All results indicate that the gradient holes endow the CIGPP with an enhanced electrochemical performance. Specifically, the CIGPP shows a significant improvement in the specific capacitance, displays rich frequency response characteristics for electrolyte ions, and exhibits a good rate performance. Also, the CIGPP supercapacitor exhibits a low self-discharge and maintains a stable electrochemical performance in different electrolyte environments because of gradient holes. More importantly, when the CIGPP is used as a substrate to fabricate a CIGPP-PANI hybrid, it still maintains good electrochemical properties. In addition, the CIGPP supercapacitor also shows excellent stability and sensitivity for monitoring human motion and deaf-mute voicing, showing potential application prospects. This study provides a reference and feasible way for the design of structure-engineered integrated paper-based energy storage devices with outstanding comprehensive electrochemical performance.