▎ 摘　　要

Nitrogen and sulfur co-doped graphene has been decorated on graphite felt electrode via a hydrothermal treatment using thiourea as sulfur and nitrogen sources for vanadium redox flow battery application. Our results demonstrate that the modification of sulfur and nitrogen co-doped graphene on graphite felt provides an effective way to improve surface area and introduce functional groups for vanadium redox reaction, resulting in a significant improvement in energy efficiency (85.37% at a current density of 80 mA/cm(2)), power density (0.4925 W/cm(2)), discharge capacity and capacity retention. These results reveal that the modification of nitrogen and sulfur co-doped graphene on graphite felts is a promising method for the enhancement of vanadium redox flow battery performance. (C) 2020 Elsevier Ltd. All rights reserved.