Constructing graphene oxide-wrapped wolframite-type 3D cube-like CuWO4 composite as a promising redox-active electrode for battery-type supercapacitors

Abstract

The electronics industry's increasing demand for swift energy storage solutions drives researchers to invest significant resources into enhancing electrode materials. Achieving optimal efficiency throughout the charging process requires meticulous attention to the designing of the morphological, structure and chemical compositions of the electrode materials. Understanding the synergies among elements and structural dynamics is pivotal for maximizing the electrodes' performance. To address these challenges, we propose a groundbreaking approach through a straightforward and cost-effective solid-state reaction method followed by an impregnation technique to design a graphene oxide-wrapped wolframite-type 3D cube-like CuWO4 (GW-CuWO4) composite matrix. This design substantially increases the electrode's surface area (5 times greater than pristine CuWO4 and 12 times greater than sphere-like Na2WO4) and enhances its mesoporous characteristics. We extensively analyzed the physicochemical properties of GW-CuWO4 and compared them with pristine CuWO4 and Na2WO4 using various analytical techniques. The electrochemical performance of all electrodes exhibited battery-type characteristics, with the supercapacitive performance thoroughly investigated and compared. The specific capacity of the GW-CuWO4 composite electrode demonstrated significant results, reaching 520.8 C g−1 at 1.0 A g−1, with outstanding rate capability retaining 93 % capacity even at a high rate of charging current of 10 A g−1. In contrast, the specific capacity and rate capability of pristine CuWO4 were 392.1 C g−1 and 87 %, respectively, and Na2WO4 showed 295.8 C g−1 and 64 %. Additionally, the GW-CuWO4 electrode displayed excellent cyclic performance, retaining 95 % capacity at 10 A g−1 compared to CuWO4 (84 %). The GW-CuWO4 electrode exhibits enhanced electrochemical performance due to the synergistic interactions between its constituent parts and its distinct 3D mesoporous composite network. High conductivity, rich redox reactions, easy electron transfer, short ion diffusion lengths, quick kinetics, and an abundance of active sites for electrochemical reactions are all made possible by this network. Presenting this cutting-edge electrode design builds a fresh framework for producing effective electrodes suited for the upcoming wave of high-performance energy storage devices.