Variable Buoyancy Device for Autonomous Underwater Vehicles

The project focuses on the development of an electrochemical variable buoyancy device for autonomous underwater vehicles. The approach is based on the electrochemistry of metal-gas batteries, wherein one electrode has a gaseous reactant and the other is a metal or metal oxide. The proposed electrochemical couple is metal hydride - hydrogen, which combines the metal hydride electrode of nickel metal hydride batteries with the hydrogen electrode of nickel - hydrogen batteries. Applying a charge current to this couple produces hydrogen gas which is passed to a flexible metal bladder. This enables rapid and precise buoyancy changes by passing a known amount of electrical charge.