Boosting Thermogalvanic Cell Performance through Synergistic Redox and Thermogalvanic Corrosion

Abstract

Thermogalvanic cells with organic redox couple (OTGCs) have received significant attention for low-grade heat harvesting due to their high thermopower, versatile molecular design, and tailorable physiochemical properties. However, their thermogalvanic conversion power output is largely hindered by slow kinetic rate, which limits practical applications. In this work, we demonstrate a high-performance liquid quinone/hydroquinone (Q/HQ) based OTGC by synergistic coupling redox reaction and thermogalvanic corrosion. By adding hydrochloric acid (HCl) into electrolyte solution, HCl not only boosts intrinsic redox kinetic rate of Q/HQ, but also induces rapid thermogalvanic corrosion of the copper electrode. Notably, these two processes reinforce each other kinetically. Consequently, the Q/HQ-based OTGC exhibits a rapid kinetic rate alongside an increased thermopower, leading to a significantly enhanced power output density. As a result, the Q/HQ-based OTGC achieves an enhanced effective conductivity σeff of 4.22 S m−1 and a record high normalized power density Pmax (ΔT)−2 of 108.7 μW m−2 K−2. This strategy provides a feasible and effective method for development of high-performance OTGCs.