Recent Advances in Thermoelectric Materials and Devices
ZHU Tie-Jun
School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
文献标识码:
1000-324X(2019)03-0233-03
文章编号:
1000-324X(2019)03-0233-03
版权声明:
2019 无机材料学报编委会 This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The increasing concern on climate change and over-reliance on fossil fuels have spurred an urgent action worldwide in developing alternative energy technologies. Thermoelectricity is the simplest technology applicable for direct heat-electricity energy conversion. Heat from different sources such as solar heat, geothermal heat, and waste heat from automobiles or other industrial processes can be directly converted into clean electricity by a thermoelectric device. A thermoelectric device can also work in reverse as a heat pump. Thermoelectric devices are of all solid-state assembly, lightweight and compact, rapid responsiveness. They possess the absence of moving parts or hazardous working fluids, and have the feasibility for miniaturization. The modular aspects of thermoelectricity make it easy to work in tandem with other energy conversion or alternative energy technologies. This is a very important feature because no single technology can meet the world’s energy needs in 21st century, We need a combination of many technologies.
The fundamental issue of thermal-electrical energy conversion is primarily the pursuit of thermoelectric materials with high figure of merit ZT. The high ZT materials should be a “Phonon-Glass Electron- Crystal” (PGEC) that simultaneously possesses a high Seebeck coefficient a, a high electrical conductivity s and a low thermal conductivity k[1]. It is difficult to satisfy these criteria in a simple crystalline bulk material since all the three quantities that govern ZT are inter-related, and a modification to any of these quantities often adversely affects the others[2]. In complex crystal systems composed of building modules with different compositions, structural symmetries and TE functions, sometimes called “hybrid crystal”, the electrical and thermal transport can be decoupled and optimized. The filled skutterudites, Cu2Se based ion conductors, BiCuSeO and novel Zintl-phase compounds provide examples of such control[3,4,5].
Over the past decade, the efforts of pursuing high ZT materials in thermoelectric study have culminated into a new paradigm, i.e. nanostructured thermoelectric materials[2,3]. This direction started ten years ago with the speculation that low dimensional materials would have enhanced properties over those of similar materials in bulk form. The nanomaterials can provide several opportunities for phonon scattering, e.g., the mass fluctuation alloying, grain boundary, strain fields, which cover wide ranges of phonon wavelength and temperature. The multiscale complexity can be tuned so as to scatter phonons more than electrons.
While improving the ZT values has always been the central task of thermoelectric study, in recent years increasing attention is being paid to the environmental friendliness and the availability of the specific thermoelectric materials. This requires not only a good thermoelectric material with a high ZT value but also it is comprised of non-toxic and abundantly available elements with high chemical and thermal stability. It is noted that most state-of-the-art thermoelectric materials are semiconducting tellurides, such as Bi2Te3, PbTe and GeTe-AgSbTe2 compounds that are widely used for thermoelectric power generation and refrigeration[3,6]. Tellurium is toxic and its abundance is only on the order of one billionth on earth. Hence it is highly desirable and urgent to identify and develop Te- and Pb-free high performance thermoelectric materials. In this spirit, the half-Heusler semiconductors and Mg-based compounds are outstanding among the most promising candidates[7].
Thermoelectric materials have been developed into a big family, including semiconductors, oxides and polymers, possessing various crystalline forms from monocrystals and polycrystals to nanocomposites. Further performance improvement needs the better understanding of thermoelectric transport mechanisms and related impacting factors[8], which has to be based on the reliable measurements of thermoelectric parameters[9]. Recently, The Materials Genome Initiative is speeding up the discovery and design of materials based on big data and high-throughput methods including calculations and characterization, which is promising for the screening of novel thermoelectric materials. However, the design principle, assembly methods and testing technique of thermoelectric module and system, although developing quickly, still lag relatively behind and fail to meet the needs of industrial applications[10]. Many challenges still lie ahead and continuous efforts have to be done in the future.
... The fundamental issue of thermal-electrical energy conversion is primarily the pursuit of thermoelectric materials with high figure of merit ZT. The high ZT materials should be a “Phonon-Glass Electron- Crystal” (PGEC) that simultaneously possesses a high Seebeck coefficient a, a high electrical conductivity s and a low thermal conductivity k[1]. It is difficult to satisfy these criteria in a simple crystalline bulk material since all the three quantities that govern ZT are inter-related, and a modification to any of these quantities often adversely affects the others[2]. In complex crystal systems composed of building modules with different compositions, structural symmetries and TE functions, sometimes called “hybrid crystal”, the electrical and thermal transport can be decoupled and optimized. The filled skutterudites, Cu2Se based ion conductors, BiCuSeO and novel Zintl-phase compounds provide examples of such control[3,4,5]. ...
Compromise Compromise and synergy in high efficiency thermoelectric materials
... The fundamental issue of thermal-electrical energy conversion is primarily the pursuit of thermoelectric materials with high figure of merit ZT. The high ZT materials should be a “Phonon-Glass Electron- Crystal” (PGEC) that simultaneously possesses a high Seebeck coefficient a, a high electrical conductivity s and a low thermal conductivity k[1]. It is difficult to satisfy these criteria in a simple crystalline bulk material since all the three quantities that govern ZT are inter-related, and a modification to any of these quantities often adversely affects the others[2]. In complex crystal systems composed of building modules with different compositions, structural symmetries and TE functions, sometimes called “hybrid crystal”, the electrical and thermal transport can be decoupled and optimized. The filled skutterudites, Cu2Se based ion conductors, BiCuSeO and novel Zintl-phase compounds provide examples of such control[3,4,5]. ...
... Over the past decade, the efforts of pursuing high ZT materials in thermoelectric study have culminated into a new paradigm, i.e. nanostructured thermoelectric materials[2,3]. This direction started ten years ago with the speculation that low dimensional materials would have enhanced properties over those of similar materials in bulk form. The nanomaterials can provide several opportunities for phonon scattering, e.g., the mass fluctuation alloying, grain boundary, strain fields, which cover wide ranges of phonon wavelength and temperature. The multiscale complexity can be tuned so as to scatter phonons more than electrons. ...
Recent advances in high performance bulk thermoelectric materials
... The fundamental issue of thermal-electrical energy conversion is primarily the pursuit of thermoelectric materials with high figure of merit ZT. The high ZT materials should be a “Phonon-Glass Electron- Crystal” (PGEC) that simultaneously possesses a high Seebeck coefficient a, a high electrical conductivity s and a low thermal conductivity k[1]. It is difficult to satisfy these criteria in a simple crystalline bulk material since all the three quantities that govern ZT are inter-related, and a modification to any of these quantities often adversely affects the others[2]. In complex crystal systems composed of building modules with different compositions, structural symmetries and TE functions, sometimes called “hybrid crystal”, the electrical and thermal transport can be decoupled and optimized. The filled skutterudites, Cu2Se based ion conductors, BiCuSeO and novel Zintl-phase compounds provide examples of such control[3,4,5]. ...
... Over the past decade, the efforts of pursuing high ZT materials in thermoelectric study have culminated into a new paradigm, i.e. nanostructured thermoelectric materials[2,3]. This direction started ten years ago with the speculation that low dimensional materials would have enhanced properties over those of similar materials in bulk form. The nanomaterials can provide several opportunities for phonon scattering, e.g., the mass fluctuation alloying, grain boundary, strain fields, which cover wide ranges of phonon wavelength and temperature. The multiscale complexity can be tuned so as to scatter phonons more than electrons. ...
... While improving the ZT values has always been the central task of thermoelectric study, in recent years increasing attention is being paid to the environmental friendliness and the availability of the specific thermoelectric materials. This requires not only a good thermoelectric material with a high ZT value but also it is comprised of non-toxic and abundantly available elements with high chemical and thermal stability. It is noted that most state-of-the-art thermoelectric materials are semiconducting tellurides, such as Bi2Te3, PbTe and GeTe-AgSbTe2 compounds that are widely used for thermoelectric power generation and refrigeration[3,6]. Tellurium is toxic and its abundance is only on the order of one billionth on earth. Hence it is highly desirable and urgent to identify and develop Te- and Pb-free high performance thermoelectric materials. In this spirit, the half-Heusler semiconductors and Mg-based compounds are outstanding among the most promising candidates[7]. ...
BiCuSeO as state-of-the-art thermoelectric materials for energy conversion: from thin films to bulks
... The fundamental issue of thermal-electrical energy conversion is primarily the pursuit of thermoelectric materials with high figure of merit ZT. The high ZT materials should be a “Phonon-Glass Electron- Crystal” (PGEC) that simultaneously possesses a high Seebeck coefficient a, a high electrical conductivity s and a low thermal conductivity k[1]. It is difficult to satisfy these criteria in a simple crystalline bulk material since all the three quantities that govern ZT are inter-related, and a modification to any of these quantities often adversely affects the others[2]. In complex crystal systems composed of building modules with different compositions, structural symmetries and TE functions, sometimes called “hybrid crystal”, the electrical and thermal transport can be decoupled and optimized. The filled skutterudites, Cu2Se based ion conductors, BiCuSeO and novel Zintl-phase compounds provide examples of such control[3,4,5]. ...
... The fundamental issue of thermal-electrical energy conversion is primarily the pursuit of thermoelectric materials with high figure of merit ZT. The high ZT materials should be a “Phonon-Glass Electron- Crystal” (PGEC) that simultaneously possesses a high Seebeck coefficient a, a high electrical conductivity s and a low thermal conductivity k[1]. It is difficult to satisfy these criteria in a simple crystalline bulk material since all the three quantities that govern ZT are inter-related, and a modification to any of these quantities often adversely affects the others[2]. In complex crystal systems composed of building modules with different compositions, structural symmetries and TE functions, sometimes called “hybrid crystal”, the electrical and thermal transport can be decoupled and optimized. The filled skutterudites, Cu2Se based ion conductors, BiCuSeO and novel Zintl-phase compounds provide examples of such control[3,4,5]. ...
Enhanced thermoelectric performance in large size PbTe bulk materials with figure of merit ZT> 2 by multi-functional alloying
... While improving the ZT values has always been the central task of thermoelectric study, in recent years increasing attention is being paid to the environmental friendliness and the availability of the specific thermoelectric materials. This requires not only a good thermoelectric material with a high ZT value but also it is comprised of non-toxic and abundantly available elements with high chemical and thermal stability. It is noted that most state-of-the-art thermoelectric materials are semiconducting tellurides, such as Bi2Te3, PbTe and GeTe-AgSbTe2 compounds that are widely used for thermoelectric power generation and refrigeration[3,6]. Tellurium is toxic and its abundance is only on the order of one billionth on earth. Hence it is highly desirable and urgent to identify and develop Te- and Pb-free high performance thermoelectric materials. In this spirit, the half-Heusler semiconductors and Mg-based compounds are outstanding among the most promising candidates[7]. ...
Realizing high figure of merit in heavy band p-type half-Heusler thermoelectric materials
... While improving the ZT values has always been the central task of thermoelectric study, in recent years increasing attention is being paid to the environmental friendliness and the availability of the specific thermoelectric materials. This requires not only a good thermoelectric material with a high ZT value but also it is comprised of non-toxic and abundantly available elements with high chemical and thermal stability. It is noted that most state-of-the-art thermoelectric materials are semiconducting tellurides, such as Bi2Te3, PbTe and GeTe-AgSbTe2 compounds that are widely used for thermoelectric power generation and refrigeration[3,6]. Tellurium is toxic and its abundance is only on the order of one billionth on earth. Hence it is highly desirable and urgent to identify and develop Te- and Pb-free high performance thermoelectric materials. In this spirit, the half-Heusler semiconductors and Mg-based compounds are outstanding among the most promising candidates[7]. ...
... Thermoelectric materials have been developed into a big family, including semiconductors, oxides and polymers, possessing various crystalline forms from monocrystals and polycrystals to nanocomposites. Further performance improvement needs the better understanding of thermoelectric transport mechanisms and related impacting factors[8], which has to be based on the reliable measurements of thermoelectric parameters[9]. Recently, The Materials Genome Initiative is speeding up the discovery and design of materials based on big data and high-throughput methods including calculations and characterization, which is promising for the screening of novel thermoelectric materials. However, the design principle, assembly methods and testing technique of thermoelectric module and system, although developing quickly, still lag relatively behind and fail to meet the needs of industrial applications[10]. Many challenges still lie ahead and continuous efforts have to be done in the future. ...
... Thermoelectric materials have been developed into a big family, including semiconductors, oxides and polymers, possessing various crystalline forms from monocrystals and polycrystals to nanocomposites. Further performance improvement needs the better understanding of thermoelectric transport mechanisms and related impacting factors[8], which has to be based on the reliable measurements of thermoelectric parameters[9]. Recently, The Materials Genome Initiative is speeding up the discovery and design of materials based on big data and high-throughput methods including calculations and characterization, which is promising for the screening of novel thermoelectric materials. However, the design principle, assembly methods and testing technique of thermoelectric module and system, although developing quickly, still lag relatively behind and fail to meet the needs of industrial applications[10]. Many challenges still lie ahead and continuous efforts have to be done in the future. ...
Thermoelectric devices for power generation: recent progress and future challenges
... Thermoelectric materials have been developed into a big family, including semiconductors, oxides and polymers, possessing various crystalline forms from monocrystals and polycrystals to nanocomposites. Further performance improvement needs the better understanding of thermoelectric transport mechanisms and related impacting factors[8], which has to be based on the reliable measurements of thermoelectric parameters[9]. Recently, The Materials Genome Initiative is speeding up the discovery and design of materials based on big data and high-throughput methods including calculations and characterization, which is promising for the screening of novel thermoelectric materials. However, the design principle, assembly methods and testing technique of thermoelectric module and system, although developing quickly, still lag relatively behind and fail to meet the needs of industrial applications[10]. Many challenges still lie ahead and continuous efforts have to be done in the future. ...
