Background

Extremely high energy density batteries are needed for underwater electric ships such as unmanned submarines and naval observatories.

Technology Overview

The lithium-seawater battery, developed by University at Buffalo researchers, is made of two compartments: the anode compartment, which encloses the metal in non-aqueous electrolyte, and the cathode compartment, which contains a porous and electrically conductive material and seawater. A solid-state metal-ion conductive membrane is used to separate the two compartments. Inlets and outlets for seawater flow channels are installed in the cathode compartment and a mechanical pump is used to control and pump seawater into the compartment.

The theoretical energy density of a Li-seawater flow battery is about 11.6 kWh/kg while the cost for replacing the lithium in the anode is about $1.2/kWh. This makes the volumetric energy density of lithium-seawater flow battery about 2 kWh/L or 2,000 kWh/m³, which is 0.0005 m³/kWh.

Figure 1.

Stage of Development

Technology Readiness Level (TRL): 2.

Benefits

The lithium-seawater battery can deliver over specific energy of 4,000 Wh/kg, which is much greater than that of any electrochemical energy storage system including hydrogen fuel cells.

Applications

Emergency backup power on underwater vehicles or other naval equipment.

Opportunity

Licensable upon conversion to regular patent.

Lithium-Seawater Battery for Backup Power on Underwater Vehicles

Patents

IP Status

Seeking