Macroporous silicon hydrogen diffusion layers for micro-fuel cells: From planar to 3D structures

摘要

In this study, we demonstrate the possibility of using macroporous silicon as a hydrogen diffusion layer in integrated planar and 3D proton exchange membrane micro fuel cells (PEMFC). In this context, silicon electrochemical etching is presented as an interesting alternative to costly deep reactive ion etching techniques. In the case of planar PEMFC, a maximum density power of 250 mW/cm~2 was measured. The second objective of our work is to enhance the fuel cell active surface. One way to increase power densities is to chemically texture the surface of the GDL supporting the fuel cell. Then, the porous silicon electrochemical etching process is applied to these 3D silicon substrates. Flow rates measured through these fully porous 3D structures are compared with planar diffusion layers.