3D ZnO hexagonal prism-decorated 2D MXene-based high-performance flexible symmetric supercapacitor

Abstract

Flexible, high-performance supercapacitors are critical for the future generation of portable and wearable electronics. In this research, we present, for the first time, the synthesis and design of a flexible supercapacitor device using ZnO hexagonal prism-decorated MXene synthesized via a hydrothermal method, serving as a highly efficient electrode material. Pristine MXene suffers from restacking, limiting its electrochemical performance; however, decorating it with ZnO hexagonal prism mitigates this issue by enhancing interlayer spacing and improving ion transport. The unique hexagonal prism morphology of ZnO, combined with the layered MXene structure, significantly enhances electrical conductivity while preventing restacking. The resulting material achieved an impressive specific capacitance of 140 F g⁻¹ at 0.5 A g⁻¹, greatly surpassing pristine MXene (73 F g⁻¹). Furthermore, it exhibited outstanding cycling stability, with 97.2 % capacitance retention after 12,000 cycles at 3 A g⁻¹. A flexible symmetric supercapacitor fabricated using this material demonstrated excellent mechanical flexibility, maintaining reliable electrochemical performance under bending angles of 0°, 60°, 90°, and 180°. The device also delivered a high energy density of 6.33 Wh kg⁻¹ and a power density of 600 W kg⁻¹, showcasing the potential of ZnO hexagonal prism decorated MXene as a promising material for advanced energy storage applications.