Self-healable polymer complex with a giant ionic thermoelectric effect

In this study, we develop a stretchable/self-healable polymer, PEDOT:PAAMPSA:PA, with remarkably high ionic thermoelectric (iTE) properties: an ionic figure-of-merit of 12.3 at 70% relative humidity (RH). The iTE properties of PEDOT:PAAMPSA:PA are optimized by controlling the ion carrier concentration, ion diffusion coefficient, and Eastman entropy, and high stretchability and self-healing ability are achieved based on the dynamic interactions between the components. Moreover, the iTE properties are retained under repeated mechanical stress (30 cycles of self-healing and 50 cycles of stretching). An ionic thermoelectric capacitor (ITEC) device using PEDOT:PAAMPSA:PA achieves a maximum power output and energy density of 4.59 μW‧m −2 and 1.95 mJ‧m −2 , respectively, at a load resistance of 10 KΩ, and a 9-pair ITEC module produces a voltage output of 0.37 V‧K −1 with a maximum power output of 0.21 μW‧m −2 and energy density of 0.35 mJ‧m −2 at 80% RH, demonstrating the potential for a self-powering source. Thermoelectric devices have received significant attention for energy generation owing to their unique advantages over traditional heat engines. Here, the authors developed a well performing stretchable and self-healable iono thermoelectric material by optimizing the thermophoresis of protons in a polymer complex PEDOT:PAAMPSA:PA polymer.