Lee, Ling-ChiehLing-ChiehLeeHong, Shao-HuanShao-HuanHongKim, Min-SuMin-SuKimJeng, U-SerU-SerJengWang, Chia-HsinChia-HsinWangSHIH-HUANG TUNGLee, Keun HyungKeun HyungLeeCHENG-LIANG LIU2025-08-142025-08-142025-06-2119448244https://www.scopus.com/record/display.uri?eid=2-s2.0-105008974280&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/731432Converting 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.falseionic liquidionic thermoelectricsionogellow-grade heat harvestingthermopower[SDGs]SDG7journal article10.1021/acsami.5c087242-s2.0-105008974280