Richard Burgess, Seapower Magazine
29 June 2015
ARLINGTON, Va. — A new battery fuel cell technology shows promise in providing more power and endurance to unmanned undersea vehicles (UUVs) and other platforms as well as less potential for fire.
Aluminum-seawater fuel cell technology, being developed by Open Water Power of Somerville, Mass., is able to “safely store about 10 times as much energy as lithium-ion batteries,” said Tom Milnes, president and chief executive officer of Open Water Power.
Milnes’ company is developing the technology for a variety of uses for defense and commercial applications, such as UUVs and the oil and gas industry. Exploration of the technology was conducted by a joint team, of which Milnes was a member, at Massachusetts Institute of Technology, Lincoln Laboratory and Woods Hole Oceanographic Institute. Open Water Power has taken the technology further from “beaker-level science,” in Milnes’ characterization, with a $450,000 in funds of from the Rapid Response Technology Office of the Defense Department, the Office of Naval Research, and the Naval Air Systems Command, delivering a developmental model of an aluminum-seawater cell to the Office of Naval Research in December.
The Naval Surface Warfare Center Carderock Division in Maryland put the first cell in an inactive state through pressure, temperature and fire testing this spring and released a report on its performance in June. The testers concluded that “early tests indicate that a reactor [battery] — when in an inactive state — does not generate hazards when exposed to extreme storage temperatures, low pressures, or fires,” according to a Navy briefing.
Open Water Power will be delivering two more cells to the Navy for testing. The next steps for testing by the Navy include a short-circuit test, a water-exposure test and performance tests “to determine energy density and characterize operational behavior,” the briefing said.
Milnes said the aluminum-seawater concept is an old idea but only recently have the barriers to making it operational been overcome. The technology was explored for primarily for its energy density but the safety of the technology also has become evident.
The Navy has had a need to develop a safer battery technology for undersea vehicles since the 2008 fire on the Advanced SEAL Delivery System submersible.