Solubility study of Y in n-type YxCe0.15Co4Sb12 skutterudites and its effect on thermoelectric properties. (June 2020)

• Record Type: Journal Article
• Authors: Qin, D.; Shi, W.; Xue, W.; Qin, H.; Cao, J.; Cai, W.; Wang, Y.; Sui, J.
• Is Part Of: Materials today physics. Volume 13(2020)
• Publication Date: 2020-06
• Subjects: Skutterudites -- Y auxiliary filler -- Lattice thermal conductivity -- Thermoelectric properties; Materials science -- Periodicals; Physics -- Periodicals; Electronic journals; 530.41
• DOI: 10.1016/j.mtphys.2020.100206
• Languages: English
• ISSNs: 2542-5293

Abstract

Abstract: Low-cost Ce has been proved to be an effective auxiliary filler for performance tuning in CoSb3 -based skutterudite, one of the most promising thermoelectric materials at medium temperature. However, the low solubility of Ce in CoSb3 makes its overall thermoelectric properties so far inferior to that with expensive and scarce Yb filler. Herein, using non-equilibrium processing, we successfully synthesized a series of double-filled skutterudites with Ce as the dominating filling element and Y as the auxiliary filler. Our investigation shows that Y filling not only optimizes the carrier concentration and thus enhances the overall power factor but also introduces additional phonon scattering and hence leads to significantly suppressed lattice thermal conductivity. The concurrently optimized electrical and thermal properties realize the maximum ZT of ~1.37 at 873 K in the Y0.05 Ce0.15 Co4 Sb12 sample, prevailing over the other involved Ce single- or even double-filled skutterudites, which will potentially facilitate a widespread application of filled skutterudites. Graphical abstract: In the Y, Ce double-filled skutterudites, the auxiliary filler Y not only strongly scatters heat-carrying phonon and suppresses the lattice thermal conductivity but also tailors the carrier concentration and improves electrical properties, collectively resulting in boosted thermoelectric performance. Image 1 Highlights: The low-cost Ce is selected as dominating filling element in skutterudites. The power factor is nicely boosted via tuning Y auxiliary filling. The lattice thermal conductivity is further suppressed through double filling. Y0.05 Ce0.15 Co4 Sb12 sample exhibits the maximum ZT of ~1.37 at 873 K.