Air-hydrogen fuel cell with two-level slotted silicon-based electrode

The design of a two-level slotted silicon-based electrode and a technology of its manufacturing by anisotropic etching of (110)-oriented Si wafers are described. The electrode contains two layers, one with wide channels and another with narrow slots. The first layer provides gas transport in an air-hydrogen fuel cell (FC), while the second layer can perform the functions of (i) a catalyst carrier and (ii) a gas-diffusion layer. It is shown that, by filling the narrow-slot layer with a carbon-platinum catalytic ink, it is possible to obtain a higher specific power on the anode due to an increase in the effective area as compared to that of a flat catalyst carrier. The operation of the two-level slotted electrode as a gas-diffusion layer was studied for an FC operating in a free-breathing cathode regime. This FC is characterized by increased power compared to that with a carbon paper and a single-level slotted Si electrode.