Dual-mode Lithium-bromine Battery


With the aid of advanced sensor and sonar capabilities, naval applications are requiring high power sources, which this technology can provide. Some naval applications requiring compact energy-dense power include submarines, missile systems, mines, torpedoes, countermeasure autonomous underwater vehicles (AUV), and sonobouys. However, by replacing seawater with hydrobromic acid or lithium bromide in water the battery can be applied to systems on land such as electric vehicles.

Problem Addressed

Many battery applications often have endurance and surge requirements. A dual-mode lithium-bromine (Li/Br) battery can operate in two separate settings, low-power mode designed for endurance and a high-power mode designed for surge requirements.


The dual-mode battery operates by modifying or changing the catholyte. Analogous to the nitrous oxide system used in race cars, which injects N2O to provide extra oxygen to increase the power output of the internal combustion engine, the dual-mode lithium-bromine/oxygen cell allows the injection of bromine as the reaction booster to provide higher power density on demand. The cell consists of a lithium metal at the anode protected by a lithium phosphorous oxynitride (LiPON) interlayer and a lithium superionic conductor (LISICON) separator. The protection layer between the anode and the electrolyte ensures the conduction of lithium ions and blocks the flow of electrons and other reactants. The cathode reaction in low power mode is the reduction of dissolved oxygen and in the high power mode is the reduction of bromine. For the low power mode a specific energy of 428.5 Whr/kg and an energy density of 471.4 Whr/L were measures. For the how power mode, a specific energy of 791.5 Whr/kg and an energy density of 1357 Whr/L.


  • Ability to operate at two power modes
  • Seawater electrolyte, which is ideal for naval applications
  • Electrolyte can be modified for electric vehicles