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Engineering Thermal Conductivity for Balancing Between Reliability and Performance of Bulk Thermoelectric Generators
Author(s) -
Kim Hee Seok,
Wang Tianbao,
Liu Weishu,
Ren Zhifeng
Publication year - 2016
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201600128
Subject(s) - thermoelectric effect , materials science , thermal conductivity , thermoelectric materials , thermoelectric generator , reliability (semiconductor) , thermal engineering , thermal , engineering physics , mechanical engineering , composite material , thermodynamics , engineering , physics , power (physics)
The nanostructuring approach has significantly contributed to the improving of thermoelectric figure‐of‐merit ( ZT ) by reducing lattice thermal conductivity. Even though it is an effective method to enhance ZT , the drastically lowered thermal conductivity in some cases can cause thermomechanical issues leading to decreased reliability of thermoelectric generators. Here, an engineering thermal conductivity ( κ eng ) is defined as a minimum allowable thermal conductivity of a thermoelectric material in a module, and is evaluated to avoid thermomechanical failure and thermoelectric degradation of a device. Additionally, there is dilemma of determining thermoelectric leg length: a shorter leg is desired for higher W kg −1 , W cm −3 , and W $ −1 , but it raises the thermomechanical vulnerability issue. By considering a balance between the thermoelectric performance and thermomechanical reliability issues, it is discussed how to improve device reliability of thermoelectric generators and the engineering thermal conductivity of thermoelectric materials.