High thermoelectric performance in Cu2Se superionic conductor with enhanced liquid-like behaviour by dispersing SiC

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2019, Vol.7 (12), p.7006-7014
• Main Authors: Jingdan Lei, Zheng, Ma, Zhang, De, Chen, Yanqun, Wang, Chao, Yang, Xiaoyun, Cheng, Zhenxiang, Wang, Yuanxu
• Format: Article
• Language: English
• Subjects: Conductors; Copper; Copper selenides; Deformation; Electrical conductivity; Electrical properties; Electrical resistivity; Figure of merit; Interfaces; Migration; Nanoparticles; Silicon carbide; Thermal conductivity; Thermoelectric materials; Thermoelectricity
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c8ta12210e

The liquid-like thermoelectric material Cu2Se has shown great promise in recent years by virtue of its good electrical properties and inherent low thermal conductivity, which could be optimized by engineering liquid copper ions for further application. Herein, we reported, for the first time, that thermoelectric performance could be remarkably improved via introducing SiC nanoparticles into the Cu2Se system. Experimental results proved that additional SiC generated more deformation and stress, which feasibly facilitated more migration of charged copper ions and in turn increased conductivity. A maximum enhancement in electrical conductivity of about 7 times in the composite with 0.05 wt% SiC content was obtained compared with the pure Cu2Se, consistent with an increase in phonon scattering by additional interfaces. We obtained a high figure of merit, ZT, of 2.0 at 875 K in the Cu2Se/0.05 wt% SiC composite, which was 186% higher than that of the pure Cu2Se (∼0.7).