Recent trends in thermoelectrochemical cells and thermally regenerative batteries

Given the ever-growing awareness on global warming, much interest has focused on new and effective ways to manage energy, especially by harvesting and exploiting low-temperature heat sources, ubiquitous in the modern environment. Here, the holy grail is the direct conversion of heat into electricity especially using thermoelectric devices, and in this contribution, we focus on thermoelectrochemical systems. We give a brief overview of the most common thermally regenerative electrochemical cells developed nowadays with a short overview of their thermodynamic derivation, and we collect some of the most recent results in terms of their thermoelectrochemical properties, in particular, their temperature coefficients. We see that although the most used redox couples are based on Fe3+/Fe2+ and their derivates, thermodiffusion effects and other entropy-related phenomena are attracting the attention of the scientific community and boosting astonishing results. On the other hand, thermally regenerative batteries are emerging, showing modest performance.