Long shelf-life, Al-anode micro-fabricated cells activated with alkaline-H2O2 electrolytes

Abstract

Aluminum-anode micro fabricated electrochemical cells activated on demand are a power-MEMS alternative. Cells of this type activated with alkaline electrolyte aqueous solution (20 νl) that contains hydrogen peroxide continue to be studied herein. Hydroxide concentration in this liquid and the cell configuration are the two issues investigated. Both affect the mechanistic kinetics of the chemical reactions involved in the production of energy and can be used to improve the energetic gravimetric density of these cells. Of the four electrolyte recipes, the highest energetic densities per activation are found in cells with a 3 M hydroxide concentration. The cell fabrication involved depositing aluminum lines on a patterned dielectric structure on top of a platinum cathode. The mesh-shaped electrode structure on the masks is designed so cells with three dissimilar cathode:anode surface areas are fabricated, each with a different number and width of aluminum lines, allowing us to deconvolute the electrode area ratio effect from the cells' dimensional characteristics. The electrode area ratio can in fact be used to obtain energetic output up to 14 KJ g-1 of aluminum and is capable of providing a power output of 3.5 mW cm-2 (at a potential of approximately 0.6 V) for about 5 min. © 2006 IOP Publishing Ltd.