Enhanced Thermoelectric Performance of PVA-Based Ionogels: Tailoring Crystallinity via Additives for Advanced Waste Heat Recovery
Journal
ACS Applied Materials and Interfaces
Journal Volume
17
Journal Issue
26
Start Page
38545
End Page
38557
ISSN
1944-8244
1944-8252
Date Issued
2025-06-21
Author(s)
Lee, Ling-Chieh
Hong, Shao-Huan
Kim, Min-Su
Jeng, U-Ser
Wang, Chia-Hsin
Lee, Keun Hyung
Abstract
Converting low-grade waste heat into electricity is crucial for green energy. This study introduces an innovative approach using poly(vinyl alcohol) (PVA)-based ionogels incorporating 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]) and specific additives: 2-carboxyphenylacetic acid (H), 2-sulfobenzoic acid (S), and 2-carboxyphenyl phosphate (P)). These additives enable successful tailoring of the crystallinity, leading to a substantial increase in the ionic figure-of-merit (zTi), from 0.006 for the PVA ionogel to 0.27 for the ionogel with P additives. Furthermore, the P-additive ionogels exhibit excellent mechanical properties, with a tensile stress of 1.75 MPa and a strain of 460%. A four-pair ionic thermoelectric capacitor made from these ionogels generates 0.33 V and achieves a power output of 2.4 mW m-2. This advancement significantly improves the thermoelectric performance of PVA ionogels, aiding in efficient waste heat utilization and sustainable energy development.
Subjects
ionic liquid
ionic thermoelectrics
ionogel
low-grade heat harvesting
thermopower
SDGs
Publisher
American Chemical Society (ACS)
Type
journal article