Template synthesis of arrays of nano fuel cells.

A method for the construction of an array of fuel cells wherein each cell is 200 nm in diameter is presented. Electrodeposition of Pt-Cu nanowires inside the cylindrical pores of an Anodisc filter membrane and the subsequent dealloying of the Cu by soaking the filter in fuming nitric acid for several hours are used to construct an array of porous platinum electrodes. About 10(9) electrically isolated cylindrical porous electrodes, each 200 nm in diameter, are formed in this manner. Utilizing two arrays of porous electrodes with a polymer electrolyte membrane or an electrolyte support matrix sandwiched between, an array of nano fuel cells is produced. This method of producing an array of coplanar fuel cells allows for the series connection of fuel cells outside the array and eliminates the need for fuel and air manifolds, greatly reducing the overall system complexity. Initial prototypes utilizing an aqueous solution of NaBH(4) as a fuel have produced power densities of ca. 1 mW/cm(2) based on an estimate of the area of the current collectors in contact with the nano-fuel-cell array and have demonstrated the ability to wire bundles of fuel cells either in parallel or in series.