Single cell seawater batteries

The author explores the feasibility of providing watts of power for years with a single-cell approach built around aluminum anodes and oxygen-consuming or hydrogen-evolving cathodes. Instead of connecting cells together in the usual manner to form a battery, a single cell can power numerous small DC/DC power converters which together provide useful voltage and current from a single low-voltage source. One of the major mechanical design problems is how to achieve deployment of a large surface area cathode and yet store the undeployed battery in a small volume. This has been achieved by designing the single-cell like a wire rope. As a result of advances in DC/DC converter technology, aluminum alloys, and oxygen reduction catalysts, single cell batteries powered by oxygen dissolved in the ocean are capable of yielding in excess of 290 Wh/pound of battery. While hydrogen evolution systems cannot thermodynamically match this level, their projected levels are still high enough to exceed primary lithium systems protected from hydrostatic pressure.<>