Affiliation:
1. Department of Chemical Engineering Pohang University of Science and Technology San 31, Nam‐gu Pohang Gyeongbuk 37673 Republic of Korea
2. Department of Materials Science and Engineering Kookmin Univ. 77 Jeongneung‐ro Seoul Seongbuk‐gu 02707 Republic of Korea
3. Department of Chemical and Environmental Engineering Yale University New Haven CT 06511 USA
Abstract
AbstractAlthough ionic hydrogels have been developed recently for innovative wearable electronics, they necessitate high humidity to diffuse ions in water and fast self‐healing, which negatively impacts their performance and stability in ambient conditions (e.g., dry environments). In this study, a series of p‐ and n‐type polymeric ionic gels (PIGs) with different ratios of ionic side chains are synthesized to allow only single‐type ions to pass through them. The results demonstrate that the repeatedly stretchable PIGs are transparent, thermally robust up to 125°C, and self‐healing. Among the series of PIGs, p‐ and n‐type PIGs with 75% ion moieties (P75 and N75) exhibit the optimum ionic conductivity (σi) (4.1 × 10−4 and 2.7 × 10−4 S cm−1) and ionic Seebeck coefficients (Si) (5.84, and ‐4.18 mV K−1) under ambient conditions (25°C and relative humidity (RH) of 30%), resulting in ZTi values of 1.87 × 10−3 and 1.18 × 10−3. Moreover, the σi and Si of PIGs are almost consistent under extremely low RH 10%. Accordingly, P(([EMIM+][SPA])0.75‐r‐MA0.25) (P75) and P(([APTA][TFSI−])0.75‐r‐MA0.25) (N75) are used to achieve stretchable ionic thermoelectrics (iTEs) with stable operability under ambient conditions (RH of 30%), satisfying all of the requirements. The iTEs with five pairs of p/n couples exhibit a thermovoltage of up to ∼0.8 V.
Funder
National Research Foundation of Korea
Ministry of Science and ICT, South Korea
Subject
Electrochemistry,Condensed Matter Physics,Biomaterials,Electronic, Optical and Magnetic Materials