Zinc Oxygen Propulsion System For Underwater Vehicles

The Navy needs high energy density, safe, cost effective propulsion systems for underwater vehicles such as torpedoes, mines, and unmanned undersea vehciles. Systems currently in development (the PEM fuel cell and the aluminum-oxygen semi-cell) present an engineering challenge for scale-down to fit the 21 inch (and smaller) hull diameters for these applications. MATSI proposes to develop a zinc-sodium chlorate system, using an ultr-high specific energy (450 wh/kg) zinc-oxygen technology the company has developed under a NASA contract, in combination with sodium chlorate oxygen delivery technology developed by NUWC. MATSI's zinc-oxygen technology uses a lightweight, efficient, safe zinc electrode (similar to that used in consumer alkaline batteries), a high performance fuel-cell type oxygen electrode, and lightweight plastic cell frames. The system has no moving parts, and because of its high thermal efficiency, only passive modes of heat transfer (free convection and conduction) are required for thermal management. The preliminary estimate or a 19 inch clear hull diameter, is a 110 kWh system, weighing 800 pounds, and occupying 9 cubic feet (55 inches of hull length). The Phase I effort includes a detailed system design study, and delivery of a 10 cell, half-scale, 4 kWh demonstration battery for testing at NUWC.