A novel zinc-air battery for electric vehicles

Abstract

A new type of zinc electrode is matched with new bifunctional air electrodes to produce a zinc-air battery of a novel design. The zinc electrode is a flow-thru type made from copper foam-metal. The air electrode uses corrosion resistant carbon black as a high area support for a highly dispersed spinel oxide electrocatalyst. The battery design employs flowing electrolyte, 12 M KOH saturated or supersaturated with zincate. Single cells as large as 200 cm/sup 2/ (1/5 EV design scale) having a capacity of 20 AH have been tested with C/4-C/16 constant current cycling. More extensive and realistic life cycle testing was done with 2 Ah cells, including the Simplified Federal Urban Driving Schedule (SFUDS) cycle. This testing has confirmed that these cells can provide the necessary transient power response required for urban EV applications. The cells achieved an average of 72 SFUDS repetitions (7.2 hrs) per discharge cycle, more than twice the number with a sealed lead acid EV battery in similar testing. The full scale (30 kWh) EV battery design based on these single cell tests indicate an energy density of 90-100 Wh/kg, 60-80 W/kg, and a very low materials cost ($50 per kWh). These results indicate this battery would provide at least twice the vehicle range of a lead acid battery of the same volume at a comparable or even lower materials cost.<>