Proton‐Coupled Electron Transfer Aided Thermoelectric Energy Conversion and Storage.

Low‐grade heat is ubiquitous in the environment and its thermoelectric conversion by the ionic conductors remains a challenge because of the low efficiency and poor sustainability. Here we demonstrate that the thermoelectric performances can be boosted by combining the Soret effect of protons and proton‐coupled electron transfer (PCET) reaction of benzoquinone and hydroquinone in hydrogels. An overall enhancement of thermopower (25.9 mV K−1), power factor (5 mW m−1 K−2), figure of merit (>2.4) and continuity of power output is achieved. Moreover, an energy‐storage function can be achieved by the redox couple, and a retained power output of 27.7 %, or 14 mW m−2 for more than 3 hours is obtained by the re‐balance of PCET reactants in the hydrogel after the removal of the temperature gradient. [ABSTRACT FROM AUTHOR]