Fast Fabrication of High‐Performance CoSb<sub>3</sub>‐Based Thermoelectric Skutterudites via One‐Step Yb‐Promoted Peritectic Solidification
Dou Li, Xiao‐Lei Shi, Zhenyu Feng, Meng Li, Jiaxi Zhu, Xiao Ma, Lili Zhang, Hong Zhong, Wei‐Di Liu, Shuangming Li, Zhi‐Gang Chen
Abstract
Abstract As a most promising mid‐temperature thermoelectric material, CoSb 3 ‐based bulk material exhibits an applicable figure‐of‐merit ( ZT ) of more than one. However, their fabrication is historically time‐consuming due to the long‐time solid‐state phase transitions from CoSb 2 to CoSb 3 . To overcome this challenge, here, a fast one‐step process is developed to fabricate n‐type Yb‐doped CoSb 3 with stable ZT of 1.12 at 765 K in <5 h. Experiments confirm Yb promotes peritectic reactions of CoSb + Liquid → CoSb 2 and CoSb 2 + Liquid → CoSb 3 , optimizes power factor, and suppresses thermal conductivity. Moreover, the dense grains, induced by the one‐step crystallization, result in outstanding mechanical properties with a Young's modulus of 171.4 GPa and a hardness of 8.8 GPa in the Yb‐doped CoSb 3 . This study indicates that the fast one‐step fabrication route can effectively promote the practical applications of CoSb 3 ‐based thermoelectrics and provide guidance for thermoelectric fabrication via rational phase design.