July 14, 2022

PolyPlusPLE400x275PolyPlus Battery Company, which is focused on developing next-generation batteries, has announced it installed a pilot manufacturing line to produce advanced Lithium Seawater Batteries (Li/SWBs) for subsea and deep ocean applications. The batteries have an energy density of 2,000 Wh/kg and greater than 1,500 WH/l, the company said.

The manufacturing line is now fully operational at the PolyPlus facility in Berkeley, Calif., allowing government, academic and industry customers to obtain fully functional batteries to support applied research and development projects.

PolyPlus said lithium seawater batteries provide key advantages over other primary batteries – such as lithium thionyl chloride – including a 10x increase in energy density and inherent safety. The new technology is based on water-stable Protected Lithium Electrodes (PLEs) invented by PolyPlus, which enable the construction of pressure tolerant batteries, having zero self-discharge, and exceptional energy density. Depending on the size and form factor, these batteries can reach densities up to 2,000 Wh/kg and >1,500 WH/l, an order of magnitude greater than competing technologies, PolyPlus said. 

This allows for a “game-changing technology” for long endurance applications, including deep ocean sensors and subsea nodes. The company said its seawater batteries do not require a pressure housing, which can significantly degrade the energy density of conventional batteries, and accordingly the Li/SWBs are able to deliver “extremely high energy density in practice.” the company added that they are close to neutral buoyancy and are exceptionally safe for use and storage on maritime vessels, vehicles and aircraft.

PolyPlus said the seawater battery can be arranged in several geometric formats, including a tubular stacking of individual cells with a total battery energy that is readily customized (for example, from 100 Wh to >10 kWh). The company added that recent Navy-sponsored open water tests of the batteries with a rated capacity of 200Ah demonstrated and confirmed that the PLE and batteries can be deployed and operated without a pressure housing in a relevant operating environment.  PolyPlus said it is working on high-rate lithium seawater batteries that can power autonomous vessels, as well as extend the mission duration for unmanned underwater vehicles (UUVs).

“PolyPlus Battery Company is grateful for the long-term support that we have received from the Office of Naval Research on the development of lithium seawater batteries and more recently from the Defense Production Act Title III program for the manufacture of this game-changing battery for marine applications,” said Steve Visco, CEO of PolyPlus. “We are exceptionally thankful to the [Department of Energy] Advanced Manufacturing Office and ARPA-E (Advanced Research Projects Agency-Energy) for their substantial support of our groundbreaking PLE battery technologies and manufacturing developments.”

For more details on the technology and company, visit the PolyPlus website here.