Seawater-drinking battery promises power boost to long-range submersibles

June 16 (UPI) -- A team of MIT scientists have developed a battery that derives power from seawater. The technology promises to extend the range and capabilities of unpiloted underwater vehicles, or UUVs.

Scientists spun the technology off into a startup company called Open Water Power. The company was recently acquired by L3 Technologies, an established tech firm.

Most submersibles use lithium ion batteries, which are expensive to maintain and have a tendency to catch on fire. OWP's battery is cheaper, safer and longer-lasting.

The batter consists of alloyed aluminum, a nickel-coated cathode and an alkaline electrolyte sandwiched between the electrodes. The battery's components require seawater to function.

Seawater is sucked in and directed at the cathode, where it is split into hydroxide anions and hydrogen gas. A reaction between the anions and aluminum anode produces aluminum hydroxide and releases electrons. The electrons are drawn back toward the cathode, completing cycle.

Harmless byproducts, aluminum hydroxide and hydrogen gas, are expelled into the ocean. Corroded aluminum anodes can be cheaply and easily replaced, prolonging the battery's lifespan.

"Our power system can drink sea water and discard waste products," Ian Salmon McKay, one of the battery's inventors, told MIT. "But that exhaust is not harmful, compared to exhaust of terrestrial engines."

Currently, the battery gives UUVs a range of 100 nautical miles. Engineers hope to eventually increase the battery's range to 1,000 nautical miles.

The U.S. Navy recently hired OWP to replace the batteries powering acoustic sensors used to identify enemy submarines. The company's batteries could be used to power variety of underwater missions, whether military, industrial or scientific.