Catalyzed Deposition of CNTs on Carbon Felt for Flow Batteries and Fuel Cells

As the worldwide demand for energy increases, the need for clean, efficient energy as a substitute for the steadily diminishing and environmentally harmful supply of fossil fuels increases as well. However, the transient nature of the leading forms of clean energy, namely solar and wind, hinder their proliferation in the energy grid despite advances in harnessing their power. As such, reduction-oxidation (redox) flow batteries have gained significant attention for their ability to convert electrical energy into chemical energy for storage and later convert it back. In the charge state, the incoming electricity (generally from some energy source) powers the reduction of a species on one side of the cell and the oxidation of a different species on the other. To discharge, the current is reversed, the oxidized species is reduced back to its original concentrations and the reduced species is oxidized back to its initial levels, as the cell provides power to an appliance or power grid. One hindrance in a flow batteryâ??s performance is low redox reaction kinetics due to poor carbon electrodes. This limitation is often overcome by stacking several layers of electrodes, which increases the material cost as well as the volume of the cell. Our lab group has developed a chemical vapor deposition process for growing multi-wall carbon nanotubes (MWCNTs) on the surface of a carbon electrode. This procedure increases the active area both for reaction and at the transport interface with the proton exchange membrane (PEM) while reducing the amount of electrode material necessary as well as the overall costs. However, carbon paper is fairly brittle and easily breakable. The goal of this project is to demonstrate that the more robust and durable carbon felt enhanced by cobalt catalyzed MWCNT growth can serve as a viable electrode in a redox flow battery. If successful, carbon felt could be explored as a substitute for carbon paper in other kinds of fuel cells, flow batteries, and other electrochemical devices.