Long shelf-life, Al-anode micro-fabricated cells activated with alkaline–H₂O₂electrolytes

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 µl) 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.

Novel enhancement of thin-form-factor galvanic cells: Probing halogenated organic oxidizers and metal anodes

“…and oxidation of M, releasing m electron-moles per mole of M, in the anode half-reaction [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] …”

“…1B shows a process-flow for the fabrication of these cells. Details concerning the microfabrication process can be found elsewhere [33,34]. The resulting thickness of the cells was 0.25 cm and a footprint of 6 cm × 6 cm.…”

“…Aluminum anode cells, with electrode interspacing on the order of microns, have been recently fabricated and studied [19][20][21][32][33][34]. Bleach solutions coupled with Al and Zn in thinform-factor, MEMS-fabricated cells provided sufficient specific energy and energy densities to power MEMS and/or other lowpower-requirement devices [35].…”

The development of BCB-sealed galvanic cells. Case study: aluminum-platinum cells activated with sodium hypochlorite electrolyte solution

“…Conventional batteries may have a short and, on occasion, unpredictable lifespan, and are often not suitable for use in situations where it is impossible or impractical to replace the battery [1]. Research effort has been intense in the development of MEMS-based batteries and fuel cells that can be an integral part of these sensor systems [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Most of the micro galvanic cells that have appeared in literature are of the reserve type and can be activated 'on-demand' [2][3][4][5][6][7][8][9][10][11][12][13][17][18][19][20], but several rechargeable options have also been reported [14,15,21].…”

“…Research effort has been intense in the development of MEMS-based batteries and fuel cells that can be an integral part of these sensor systems [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Most of the micro galvanic cells that have appeared in literature are of the reserve type and can be activated 'on-demand' [2][3][4][5][6][7][8][9][10][11][12][13][17][18][19][20], but several rechargeable options have also been reported [14,15,21]. 'On-demand' systems have the advantage of a long shelf life prior to introduction of the electrolyte, when using a stable electrolyte.…”