Regulation of Electrode–Electrolyte Interactions for Improved Heat Recovery of a Thermo-Induced Electric Double-Layer Capacitor

Low-grade heat recovery through ion redistribution (i.e., Soret effect) in electric double-layer capacitors is a recent emergence for the conversion of thermal energy into electrical energy. A popular approach to improving performance such devices optimizing composition electrolyte. However, addition thermodiffusion behavior electrolyte ions, electrode–electrolyte interactions also play vital role determining ionic Seebeck coefficient, although it has not been clearly investigated. In this work, crucial thermoelectric efficiency demonstrated by employing vertical graphene as base material surface modification. After modification via ozone treatment, oxygen-containing functional groups are enriched on sheets. interfacial between electrode and electrolyte, coefficient largely enhanced 4.6-fold (up 1 mV K–1) while capacitance improved 1.29 times. Density theory calculations reveal that high response originates from stronger ion–electrode interaction higher charge transfer groups. addition, stored supercapacitors can be extracted discharging resistor. The findings study help us better understand increasing providing new strategy heat-to-electric conversion.