High-Performance Flexible Symmetric Supercapacitor Device Based on Nitroaniline-Functionalized Benzoquinone

Abstract

A simple approach to design the molecular architecture based on modified benzoquinone and its flexible supercapacitor device is demonstrated. In present work, two electron-withdrawing subunits such as 2-nitroaniline (NA) and 3,5-dinitro aniline (DNA) are utilized to functionalize benzoquinone (BQ) core. As-prepared electrode materials based on BQ-NA and BQ-DNA on graphite foil (GF) are directly employed to fabricate a three-electrode supercapacitor (SC) device in 1 M H₂SO₄ electrolyte. At 0.5 A g^–1 current density, the BQ-DNA/GF electrode-based SC can deliver higher specific capacitance (C_sp) of 341.13 F g^–1 compared to the BQ-NA/GF SC device 322.47 F g^–1. This could be ascribed to the higher electron-withdrawing effect of the four –NO₂ groups in BQ-DNA. Moreover, two-electrode BQ-DNA/GF//BQ-DNA/GF symmetric SC device and flexible symmetric supercapacitor (SSC) device were created using the GF surface. The BQ-DNA/GF-based FSSC device at a 0° bending angle exhibits noticeable C_sp with 81.66% C_sp retention after 5000 cycles at 1 mA cm^–2 current density. The highest energy density of 12.81 μW h cm^–2 at 1.36 mW cm^–2 power density was achieved for FSSC. The FSSC cell configuration at 180° bending angle also retains excellent C_sp. The present work provides a way to design high-performance energy storage materials based on organic compounds for flexible electronics and wearable device architectures.