On Wafer Thin Micro Batteries: Micro-fabrication, Towards the Development of Aluminum-anode High Performance Cells

Reduction in size and weight of micro-electronic devices becomes limited by the availability of suitable power sources. This paper presents micro-fabrication routes of an aluminum anode/oxygenated alkaline electrolyte/platinum cathode micro cell as a first step towards the development of highly efficient thin form factor aluminum anode cells. On-demand microfluidic addition of electrolyte can offer long shelf life. Several cell designs are made on a single wafer allowing for variation of the electrode area ratio; this ratio affects the aluminum anode utilization efficiency. Cell’s open circuit voltages are in the 1.2-1.4 Volt range. Several geometries provide high current densities relative to the cell’s overall size when subjected to small load resistances (up to 2 milliamps per cm). A preliminary comparison of anode utilization efficiencies (energy per unit gram of deposited aluminum) among fabricated cells with various platinum aluminum area ratios is presented.