Open AccessTailoring Intermolecular Interactions Towards High‐Performance Thermoelectric Ionogels at Low Humidity
Author(s) -
Zhao Wei,
Sun Tingting,
Zheng Yiwei,
Zhang Qihao,
Huang Aibin,
Wang Lianjun,
Jiang Wan
Publication year - 2022
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202201075
Subject(s) - materials science , oxide , chemical engineering , polymer , polyethylene , amorphous solid , humidity , polyethylene oxide , ionic bonding , ionic conductivity , intermolecular force , ionic liquid , relative humidity , polymer chemistry , ion , nanotechnology , composite material , organic chemistry , chemistry , electrode , thermodynamics , molecule , metallurgy , physics , catalysis , electrolyte , engineering
Development of ionic thermoelectric (iTE) materials is of immense interest for efficient heat‐to‐electricity conversion due to their giant ionic Seebeck coefficient ( S i ), but challenges remain in terms of relatively small S i at low humidity, poor stretchability, and ambiguous interaction mechanism in ionogels. Herein, a novel ionogel is reported consisting of polyethylene oxide (PEO), polyethylene oxide‐polypropylene oxide‐polyethylene oxide (P123), and 1‐ethyl‐3‐methylimidazolium acetate (Emim:OAC). By delicately designing the interactions between ions and polymers, the migration of anions is restricted due to their strong binding with the hydroxyl groups of polymers, while the transport of cations is facilitated through segmental motions due to the increased amorphous regions, thereby leading to enlarged diffusion difference between the cations and anions. Moreover, the plasticizing effect of P123 and Emim:OAC can increase the elongation at break. As a consequence, the ionogel exhibits excellent properties including high S i (18 mV K −1 at relative humidity of 60%), good ionic conductivity (1.1 mS cm −1 ), superior stretchability (787%), and high stability (over 80% retention after 600 h). These findings show a promising strategy to obtain multifunctional iTE materials by engineering the intermolecular interactions and demonstrate the great potential of ionogels for harvesting low‐grade heat in human‐comfortable humidity environments.