WO3 Nanoparticles Applied in Nanosheets to Improve VRFB Performance

Researchers in China have developed a hybrid film based on two-dimensional WO₃ nanoparticles to improve the performance of vanadium oxide liquid flow batteries (VRFB).

A team from the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, embedded graphene oxide (GO) nanosheets in a perfluorinated sulfonic acid (PFSA) matrix to act as a ‘barrier’ to reduce the penetration of vanadium ions.

Tungsten trioxide (WO₃) nanoparticles were grown on the surface of GO nanosheets to overcome the electrostatic effect and to improve the hydrophilicity and dispersibility of GO nanosheets.

Severe vanadium ion permeation of the PFSA ion exchange membrane (IEM) used in most VRFB will shorten the life of the cell and result in suboptimal cell performance.

The study was published in November in the journal Advanced Functional Materials. Dr. Ye, the first author of the study, said, "These hydrophilic tungsten trioxide nanoparticles on the surface of GO nanosheets act as plasmonic active sites and facilitate plasmon transport."

Tungsten trioxide nanoparticle sheets were embedded in a novel PFSA membrane with a sandwich structure that was also stabilized with a thin layer of polytetrafluoroethylene (PTFE). This allows the graphene oxide sheet to act as a barrier to reduce the penetration of vanadium ions.

Nanoparticles also act as active sites to facilitate proton transport, resulting in high coulombic efficiency (>98.1%) and high energy efficiency (>88.9%).

This exceeds the efficiency of commercially available membranes and also addresses stability issues, the authors said. The team says the experiments show the hybrid membranes are well suited for vanadium redox liquid flow batteries.

In a previous study published in the Chemical Engineering Journal, the team developed a sandwich structured composite membrane based on one-dimensional functionalized silicon carbide nanowires.

The researchers introduced functionalized silicon carbide nanowires in a PFSA matrix and sandwiched an ultrathin porous PTFE layer. This hybrid membrane with WO₃ nanoparticles not only maintains good plasmonic conductivity but also effectively reduces vanadium ion penetration, thus improving the performance of the VRFB cell.

These studies provide a preparation strategy for the design of high-performance IEMs for VRFBs based on one- and two-dimensional modified materials, which can be extended to other fields, including water treatment and fuel cells.

• < Prev
• Next >