High Surface Area Multi-Wall Carbon Nanotube Electrodes for H2-Br2 fuel Cells

The regenerative H₂-Br₂ fuel cell has been a subject of great interest and is considered as one of the great candidates for large scale electrical energy storage [1, 2]. Since the bromine reactions in this fuel cell system do not need any precious metal catalysts, plain porous carbon paper can be used as an electrode material. However, these porous carbon electrodes have low surface area and hence multiple electrode layers are employed to improve the active surface area [2]. In our previous study, we used a two-step synthesis process that involves electrodeposition of catalyst nanoparticles followed by chemical vapor deposition (CVD) of carbon nanotubes [3]. Scanning electron micrographs of the materials obtained by this process are shown in Figure 1. As a way to simplify the process and reduce the cost of the produced material, a single step process is explored. In this process the catalyst nanoparticles are deposited on the carbon electrode via thermal reduction in a hydrogen environment and subsequently carbon nanotubes are grown. The whole process is accomplished in a single step. This new process, its effectiveness, and the performance of the materials created by this new process will be discussed in this presentation.

References

1. Haley Kreutzer, Venkata Yarlagadda, and Trung Van Nguyen, J. Electrochem Soc., 159(7), F331 (2012).
2. Kyu Taek Cho, Paul Ridgeway, Adam Z. Weber, Sophia Haussener, Vincent Battagalia, and Venkat Srinivasan, J. Electrochem. Soc., 159(11), A1806 (2012).
3. Venkata Yarlagadda and Trung Nguyen, ECS Transactions, 58(36), 25 (2014).

Acknowledgements

This work was funded by NSF through grant number EFRI-1038234 and DOE/ARPA-E under award number DE-AR000026.