N, B codoped graphite felt for high‐performance 1,8‐dihydroxyanthraquinone redox flow battery

Abstract

In this article, a graphite felt electrode was modified by NS double‐element and NB double‐element codoping. The surface morphology, crystal structure, element content, and surface chemical state of the modified electrode were characterized by scanning electron microscopy, X‐ray powder diffraction (XRD), Raman spectroscopy, and X‐ray photoelectron spectroscopy. The electrochemical performance of the modified electrode was evaluated by cyclic voltammetry, electrochemical impedance spectra, and a single cell. The results show that nitrogen (N) and boron (B) double‐element codoping can enhance the catalytic activity of graphite felt and create abundant defect sites, which increases the electrocatalytic activity by approximately a factor of 2. The reason why the doped graphite felt can obtain higher electrocatalytic activity may be related to the synergy between N and B atoms, especially the synergy between pyridine‐N and BC3, and the resistance of the first charge transfer reaction of 1,8‐dihydroxyanthraquinone on the doped graphite felt electrode is then reduced.