Temperature impact on thermo-electrochemical behavior of silicon-based photoelectrochemical flow cells

Increased attention has been focused on photoelectrochemical redox flow cell systems as a potential integrated technology for simultaneously converting and storing intermittent solar energy. Photoelectrochemical voltammetry and impedance spectroscopy tests were conducted using a single-junction c-Si photoelectrode immersed in Fe(CN)63-/4- under thermal load to evaluate the temperature effect on the thermo-electrochemical performance of silicon-based photoelectrochemical cells. It was observed that the current density significantly increased with temperature as a consequence of enhanced kinetics and electrolyte characteristics, while a detriment to the potential output was identified and predominantly attributed to variations of photovoltaic characteristics. Moreover, it was demonstrated that mass transport enhancement reaches its maximum contribution at 45 °C, followed by a slowdown in the observed trends at higher temperatures, which may lead to improved design development and optimized working conditions.