Flexible Solid-State Supercapacitors with High Areal Performance Enabled by Chlorine-Doped Graphene Films with Commercial-Level Mass Loading

Abstract

Flexible supercapacitors (FSCs) are promising energy suppliers for the emerging wearable devices. Because of the limited human body surface area, it is vital to prepare a flexible electrode with high areal performance. To address this challenge, we propose a facile hydrochloric acid (HCl) solvothermal strategy to fabricate high areal performance chlorine-doped reduced graphene oxide films (Cl-RGOFs). Owing to the electron-withdrawing effect induced by the doped Cl atoms and reducibility of HCl, the electrical conductivity of Cl-RGOF enhanced 2.5 times compared with the pristine-reduced graphene oxide film, which effectively decreased internal resistance, ensuring impressive capacitive performance. As a result, Cl-RGOF exhibits near-linear growth of specific areal capacitance with the increasing of mass loading to the commercial level. For flexible solid-state supercapacitors (FSSCs), Cl-RGOFs with 11 mg cm–2 mass loading present high areal capacitance of 2312 mF cm–2 and 78.7% capacitance retention from 1...