Ultrafine SnO2 in situ modified graphite felt derived from metal–organic framework as a superior electrode for vanadium redox flow battery

Metal–organic framework (MOF) and its derivatives have low-cost, controllable structure, and good catalytic performance, which are often used in the electrochemical field. In this work, SnO 2 in situ modified graphite felt (SnO 2 /GF) is prepared by hydrothermal method then simple thermal treatment using Sn-based MOF (Sn-MOF) as precursor. SnO 2 is uniformly and firmly distributed on the GF surface rather than the common agglomeration and poor bonding of metal oxides on carbon-based electrodes, providing stable active centers for the VO 2+ /VO 2 + and V 2+ /V 3+ redox reactions. At 250 mA·cm −2 , the energy efficiency of the battery with SnO 2 /GF remains at 63.2%, while the blank one has failed. The former battery, at 100 mA·cm −2 , has higher energy efficiency and good cycle stability (over 200 cycles). The battery performance of this study is better than that of most previous report in metal oxide-related work. This work obtains high-performance composite electrode by simple treatment of MOF, which provides a reference for the application of MOF in vanadium redox flow battery. Graphical abstract