Aqueous Asymmetric Supercapacitors with Pyrenetetraone‐Derived Pseudocapacitive Polymer‐Functionalized Graphene Cathodes Enabling a 1.9 V Operating Window

Abstract

Pseudocapacitive polymers have garnered significant attention in the realm of supercapacitors due to their versatile molecular design capabilities, cost‐effectiveness, and impressive electrical conductivity. However, limited by the low capacity and short cycle life, the investigation on conducting polymers for potential electrode materials is still insufficient. Herein, a series of pyrenetetraone‐derived polymers with pyrazine units are designed and synthesized. Furthermore, UV–vis spectroscopy demonstrates the different interaction behavior between the polymers and reduced graphene oxide (rGO), which can further indicate the performance difference of the composite electrodes. As a result, the pseudocapacitive polymer/rGO composite electrode (2/1 PPYT/rGO) exhibits a high specific capacitance of 591 F g−1 at 1 A g−1 in a 1 m sulfuric acid electrolyte. The asymmetric supercapacitor (ASC) assembled by the 2/1 PPYT/rGO cathode and the annealed Ti3C2Tx anode (2/1 PPYT/rGO//A‐Ti3C2Tx) delivers an excellent energy density of 38.1 Wh kg−1 at a power density of 950 W kg−1. Additionally, both devices demonstrate outstanding stability, retaining over 90% of their capacity after 15 000 charge/discharge cycles. As a result, these carefully engineered organic polymers, with their well‐thought‐out structural designs, showcase exceptional electrochemical performance, positioning them as highly promising candidates for the next generation of high‐performance energy storage materials.