Dynamic Thermally Regenerative Electrochemical Cycle System Concentration Tracking for Efficient Control

Abstract

Particularly in the transportation sector, waste heat originating from ultra-low-temperature sources (25–80 °C) represents a significant but largely untapped energy resource. With conventional heat recovery solutions, this type of heat loss is either not or only poorly exploitable. Therefore, thermally regenerative electrochemical cycles offer a promising solution, as they can directly convert low-temperature thermal energy into electricity. In this research, the dynamic behavior of a system using iron- and iodine-based redox pairs was investigated. In the model, the temporal variations of reactant concentrations were simulated over a 24-hour period, along with the electromotive force. Based on our results, the system's electromotive force closely follows the concentration changes, which means that the regeneration process can be effectively controlled solely based on voltage. This enables the optimization of pump operation using voltage as the input parameter for pump control, avoiding unnecessary pump cycling. The method may be particularly promising for dynamic applications in vehicles, where concentration measurement is difficult to implement.