Integration of carbon felt gas diffusion layers in silicon micro fuel cells

We have integrated carbon felt, a traditional fuel cell gas diffusion layer, with silicon micro fuel cells. To this end we used two silicon microfabrication procedures using reactive ion etching: formation of black silicon and sinking of flowfield. The former decreases electrical contact resistance to the diffusion layer, the latter serves to contain the reactant gases. The micro fuel cells, where the flowfield was covered by black silicon nano-needles, showed better performance (127 mW cm⁻²) compared to the same cells without black silicon (114 mW cm⁻²). The black silicon fuel cells were also more stable during an overnight chronoamperometric measurement. (paper)