Solar-driven thermally regenerative electrochemical device for continuous electricity production: A thermodynamic analysis

Abstract

Solar-driven thermally regenerative electrochemical (STREC) device is a promising pathway for efficient green electricity production. The potential of this device is enabled by its full solar spectrum absorption, low fabrication cost, as well as scalability in design. We propose a continuous operation STREC device with its potential assessed by a comprehensive thermodynamic model-based analysis under various device designs, material choices, and operation conditions. The understanding was then used for the optimization and operation strategies of the proposed STREC device. The highest contribution to the total heat loss is found to be the radiative heat loss of the hot cell and the sensible heat loss due to electrolyte cycling, which is dictated by the temperature differences. Concentration overpotentials take the most proportion of the electrical loss induced by the inefficient mass transfer in porous electrodes. The results reveal that STREC device with the solar absorbing and reacting multifunctional electrode can reach a solar-to-electricity efficiency of 12.67% under an optimized condition which is promising to compete with existing solar electricity production technologies. The model developed in this study also offers a fast evaluation platform for material screening, device design, and operational condition optimization.