Optimal current paths for model electrochemical systems

Optimal control theory is used to determine process limits for a well-stirred fuel cell and a diffusive flow fuel cell, both operating with nonzero flows and in a finite time. Current paths and optimal end states are determined for cells constrained to provide either maximum work output, maximum effectiveness, or maximum profit. A constant current path is found to optimize these three criteria of process performance for the well-stirred fuel cell. In the diffusive flow fuel cell qualitatively different, nonmonotonic current trajectories are obtained for maximum work and maximum profit.