Mechanically Adaptative and Environmentally Stable Ionogels for Energy Harvest

Converting building and environment heat into electricity is a promising strategy for energy harvest to tackle global energy and environmental problems. The processing challenges, mechanical brittleness, and low environmental tolerance of typical thermoelectric materials, however, prevent them from realizing their full potential when employed in outdoor building systems. Herein, a general concept based on synergistic ionic associations to significantly improve the mechanical properties and harsh environment stability for high-performance ionic-type thermoelectric (i-TE) gels is explored. They demonstrate extraordinarily high stretchability (1300-2100%), fast self-healing (120 s), temperature insensitivity, and great water-proof performance, and could be painted on a variety of surfaces. The n-type ionic Seebeck coefficient is up to -8.8 mV K-1 and the ionic conductivity is more than 0.14 mS cm(-1). Both exhibit remarkable thermal and humidity stability (293-333 K, 20-100 RH%), which are rarely achieved in previous studies. Even on a cloudy day, the open-circuit thermovoltage for a painted i-TE array with an area of about 8.5 x 10(-3) m(2) is above 2 V. This research offers a promising approach for gathering significant waste heat and even solar energy on outside building surfaces in an effective and sustainable manner.

Automated summary

Converting building and environment heat into electricity is a promising strategy for energy harvest. However, typical thermoelectric materials face challenges in outdoor building systems due to processing difficulties, mechanical brittleness, and low environmental tolerance. This research explores a concept based on synergistic ionic associations to improve the mechanical properties and harsh environment stability of ionic-type thermoelectric gels. These gels demonstrate high stretchability, self-healing ability, temperature insensitivity, and water-proof performance, and can be applied to various surfaces. They also exhibit remarkable thermal and humidity stability, and can generate significant thermovoltage even on cloudy days.