Magnesium-solution phase catholyte seawater electrochemical system

A magnesium-solution phase catholyte semi-fuel cell (Mg-SFC) system was investigated as an energetic electrochemical system for low rate, long endurance undersea vehicle applications. This electrochemical system consisted of a magnesium anode and a solution phase catholyte of hydrogen peroxide or hypochlorite, in a seawater electrolyte. Polarization profiles of the Mg-SFC were performed to determine the corresponding voltages at applied current densities ranging from 10 to 50 mA cm−2. Voltages of 1.0 V to 1.8 V were observed at these current densities. Constant current-density tests at 25 mA cm−2 for 60 min were also performed to determine voltage stability with time. These tests showed voltages of 1.3 V when a magnesium anode and an electrocatalyst of nickel foil catalyzed with palladium and iridium were utilized. When an electrocatalyst of planar carbon catalyzed with palladium and iridium was tested, the corresponding voltage was 1.5 V.