High performance miniature glucose/O2 fuel cell based on porous silicon anion exchange membrane

•We report a new ammonium functionalized porous silicon as anion exchange membrane.•A miniature alkaline fuel cell based on modified mesoporous silicon as membrane.•The air breathing glucose fuel cell delivers a power density of 7 mW cm− 2 at 0.4 V.

Mesoporous silicon membranes are functionalized with ammonium groups and evaluated as high efficient anion exchange membrane in a miniaturized alkaline glucose fuel cell setup. N-Trimethoxysilylpropyl-N,N,N-trimethylammonium chloride is grafted onto the pore walls of porous silicon resulting in the anionic conductivity enhancement. The functionalization process is followed by FTIR spectroscopy where the optimized parameter could be determined. The ionic conductivity is measured using impedance spectroscopy and gives 5.6 mS cm− 1. These modified mesoporous silicon membranes are integrated in a specially designed miniature alkaline (pH 13) glucose/air fuel cell prototype using a conventional platinum-carbon anode and a cobalt phthalocyanine-carbon nanotube cathode. The enhanced anion conductivity of these membranes leads to peak power densities of 7 ± 0.12 mW cm− 2 at “air breathing” conditions at room temperature.

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