Boosting High-Performance Aqueous Zinc-Ion Hybrid Capacitors via Organic Redox Species on Laser-Induced Graphene Network

Hybrid zinc-ion capacitors combine the energy storage capabilities of zinc-ion batteries with the high-power output of supercapacitors. However, the limited cycle life and narrow electrochemical window of hybrid zinc-ion capacitors currently restrict their potential applications. Herein, a hybrid zinc-ion capacitor is fabricated on laser-induced graphene (LIG) based on in situ electropolymerization of organic compound poly(8-amino-2-naphthol). The electropolymerized long-conjugated chain polymers on the 3D conductive framework of LIG can enhance reaction kinetics, suppress the dissolution of organic compounds, and boost capacity. Simultaneously, hydrogen bonds form between polymer chains, aiding in proton transport. The assembled Zn//carbon cloth/LIG/poly(8-amino-2-naphthol) hybrid zinc-ion capacitors possess a high specific capacity of 308 mAh g-1 at 0.1 mA cm-2, which is twice as much as that of the batteries without LIG. Additionally, these hybrid capacitors can stably endure 10 000 cycles at a current density of 5 mA cm-2. The hybrid zinc-ion capacitor, utilizing poly(8-amino-2-naphthol) on laser-induced graphene network presents a high specific capacity of 308 mAh g-1 at 0.1 mA cm-2, and demonstrates an exceptional cycling performance over 10 000 cycles with a retention rate of 99.98%. image