Regenerative Energy Storage System for Space Exploration Missions

This paper describes the development and testing of a 1 kW reversible solid oxide fuel cell intended for energy storage on space exploration missions, particularly for long term Mars exploration. The energy is stored as H 2 or CO produced by electrolysis of H 2 O or CO 2 . The reactants are then converted back to its original composition by producing electricity.The breadboard was operated for 1250 hours alternating between electrolyser mode and fuel cell mode with H 2 /H 2 O as reactants. During the tests, as long as the mechanical integrity of the system was maintained, no degradation effect was observed. At the end of the test period, the fuel cell was operated for three full cycles (approx. 50 hours) with CO/CO 2 as reactants. The performance on CO/CO 2 was lower than for hydrogen, but sufficient to be used in a compact energy storage system for Mars exploration.