Anion Size Effect on Electrode Potential in a Nanoporous Carbon

When two half-supercapacitors are of different temperatures and connected together, since the electrode potential is thermally dependent, a significant output voltage is generated. This thermally induced capacitive effect can be employed for harvesting and storing low-grade heat. In the current study, the effects of anion size are investigated experimentally. In the nanoporous carbon under investigation, the electrode potential increases with temperature. The thermal sensitivity of electrode potential increases somewhat linearly with the anion size, suggesting that using large anions is beneficial. These unique phenomena should be attributed to the unique solvated structures and ion distribution characteristics in the confining nanoenvironment.