In Situ Grown Tungsten Trioxide Nanoparticles on Graphene Oxide Nanosheet to Regulate Ion Selectivity of Membrane for High Performance Vanadium Redox Flow Battery

Abstract

The application of vanadium redox flow batteries (VRFBs) has encountered challenges because the most commonly used commercial membrane (perfluorinated sulfonic acid, PFSA) has severe vanadium ion permeation, which yields poor stability of the battery. Herein, a PFSA‐based hybrid membrane with a sandwich structure created using a reinforced polytetrafluoroethylene thin layer with hydrophilic nanohybrid fillers is developed. The tungsten trioxide (WO3) nanoparticles are in situ grown on the surface of graphene oxide (GO) nanosheets to overcome the electrostatic effect, and to enhance the hydrophilicity and dispersibility of GO nanosheets, which is embedded in the PFSA matrix to act as a “barrier” to reduce vanadium ions permeation. In addition, these hydrophilic WO3 nanoparticles on GO nanosheets surface serve as proton active sites to facilitate proton transportation. As a result, at 120 cm−2, the cell of the hybrid membrane displays high Coulombic efficiency (over 98.1%) and high energy efficiency (up to 88.9%), better than the commercial Nafion 212 membrane at the same condition. These performances indicate the proposed hybrid membrane is applicable for VRFB application. Also, this design method of the membrane can be extended to other fields including water treatments and fuel cells.

A Nafion/polybenzimidazole composite membrane with consecutive proton-conducting pathways for aqueous redox flow batteries

“…6i). 15,[20][21][22][42][43][44] Besides, the selfdischarge time of the battery with the NP-Fiber membrane reaches 150 h, which is strikingly higher than that with the N212 membrane (60 h) in Fig. 6h, further demonstrating the high ion selectivity of the optimized NP-Fiber-3 membrane.…”

“…However, the traditional Naon membranes suffer a high water uptake and large swelling ratio due to the hydrophilic sulfonate side chains and microphase separation structure. 15,36 In contrast, PBI membranes feature a low water uptake and small swelling ratio as a result of rigid polymer chains and their compact packing. 11,34 Therefore, incorporating the PBI matrix into the Naon nanober networks could help decrease the water uptake and prevent the hydrophilic networks from swelling in the electrolytes, thus enhancing the ion permselectivity and dimensional stability of the composite membrane.…”

“…11,12 Unfortunately, to date, these membranes have not realized large-scale commercial applications, limited by either poor chemical stability (e.g., SPEEK, QAPSF) 13 or low proton conductivity (e.g., PBI). 14 In view of the unparalleled chemical stability and proton conductivity of Naon resins, considerable efforts have been dedicated to the other direction, promoting the ion selectivity of Naon membranes through incorporating inorganic nanollers, [15][16][17] introducing a selective layer 18,19 or blending with selective polymers. 20,21 For instance, Yu et al incorporated graphene oxide nanosheets into the Naon membrane, leading to a 5% higher coulombic efficiency (CE) than the recast membrane in the VRFB single cell performance test.…”

Research progress on nanoparticles applied in redox flow batteries

“…Hydrophilic channels for vanadium ion transport are restricted, which effectively reduces the permeability of VO 2+ . On this basis, Ye et al 28 in situ grown WO 3 nanoparticles on graphene oxide nanosheets and applied them to enhance ion selectivity of perfluorosulfonic acid membranes (PFAS) in VRFB. WO 3 nanoparticles strengthen the dispersibility and hydrophilicity of GO when embedded in the PFSA matrix.…”

Preparation and Electrocatalytic Activity of a Cobalt Mixed Nitrogen 3D Carbon Nanostructure @ Carbon Felt toward an All-Vanadium Redox Flow Battery

“…Therefore, some low-cost transition metal-oxide electrocatalysts such as Mn 3 O 4 , PbO 2 , WO 3 , Nb 2 O 5 , CeO 2 , and IrO 2 have been substituted for noble metals to improve the catalytic activity of VRFBs. However, this kind of electrode is unstable in an acid electrolyte [29][30][31].…”