Robust bendable thermoelectric generators enabled by elasticity strengthening
Wenjun Ding, Xinyi Shen, Min Jin, Yixin Hu, Zhiwei Chen, Erchao Meng, Jun Luo, Wen Li, Yanzhong Pei
Abstract
Using body heat for instance, thermoelectric generators have promising applications for driving wearable electronics continuously but remain a challenge in terms of recoverable flexibility, as known highly-performing thermoelectrics are usually inorganics showing rigidity. It is conceptualized in this work a large elastic strain ensuring both a largely-curved recoverable bending and a full recoverability in thermoelectric performance after enormous bendings. This leads the current work to focus on a microstructure engineering approach for strengthening the elasticity of Ag2Se, in which dense dislocations and refined grain induced by a multi-pass hot-rolling technique enable a significant enhancement in elasticity. The resultant hot-rolled elastic thin thermoelectric generators realize a record bendability, for at least 1,000,000 times at a tiny bending radius of 3 mm with an extraordinary power density. Such a bendability is applicable to the most curved surfaces of a human body, suggesting a promising strategy for powerful wearable thermoelectrics of all inorganics. The authors strengthen the elasticity of Ag2Se by microstructure engineering approach, realizing bendability of the thermoelectric generator for at least 1,000,000 times at a tiny bending radius of 3 mm with a high power density.