Thermoelectric generators(TEGs)play a critical role in collecting renewable energy fromthe sun and deep space to generate clean electricity.With their environmentally friendly,reliable,and noise-free operation,TEGs of...Thermoelectric generators(TEGs)play a critical role in collecting renewable energy fromthe sun and deep space to generate clean electricity.With their environmentally friendly,reliable,and noise-free operation,TEGs offer diverse applications,including areas with limited power infrastructure,microelectronic devices,and wearable technology.The review thoroughly analyses TEG system configurations,performance,and applications driven by solar and/or radiative cooling,covering non-concentrating,concentrating,radiative cooling-driven,and dual-mode TEGs.Materials for solar absorbers and radiative coolers,simulation techniques,energy storage management,and thermal management strategies are explored.The integration of TEGs with combined heat and power systems is identified as a promising application.Additionally,TEGs hold potential as charging sources for electronic devices.This comprehensive review provides valuable insights into this energy collection approach,facilitating improved efficiency,reduced costs,and expanded applications.It also highlights current limitations and knowledge gaps,emphasizing the importance of further research and development in unlocking the full potential of TEGs for a sustainable and efficient energy future.展开更多
A Solid Oxide Fuel Cell(SOFC)is an electrochemical device that converts the chemical energy of a substance into electrical energy through an oxidation-reduction mechanism.The electrochemical reaction of a solid oxide ...A Solid Oxide Fuel Cell(SOFC)is an electrochemical device that converts the chemical energy of a substance into electrical energy through an oxidation-reduction mechanism.The electrochemical reaction of a solid oxide fuel cell(SOFC)generates heat,and this heat can be recovered and put to use in a waste heat recovery system.In addition to preheating the fuel and oxidant,producing steam for industrial use,and heating and cooling enclosed rooms,this waste heat can be used for many more productive uses.The large waste heat produced by SOFCs is a worry that must be managed if they are to be adopted as a viable option in the power generation business.In light of these findings,a novel approach to SOFC waste heat recovery is proposed.The SOFC is combined with a“Thermoelectric Generator and an Alkali Metal Thermoelectric Converter(TG-AMTC)”to transform the excess heat generated by both the SOFC and the TG-AMTC.The proposed TG-AMTC is evaluated using a number of performance indicators including power density,operating temperature,heat recovery rate,exergetic efficiency,energy efficiency,and recovery time.The experimental results state that TG-AMTC has provided an exergetic efficiency,energetic efficiency,and recovery time of 97%,98%,and 23%,respectively.The study proves that the proposed TG-AMTC for SOFC is an efficient method of recovering waste heat.展开更多
Thermoelectric generators,with the unique ability to convert temperature gradients into electricity,have long been acknowledged as a sustainable technique for waste heat recovery.The remarkable advancements in both th...Thermoelectric generators,with the unique ability to convert temperature gradients into electricity,have long been acknowledged as a sustainable technique for waste heat recovery.The remarkable advancements in both thermoelectric materials and devices have substantially propelled the practical applications of thermoelectric generators.The capability of generating electricity through the temperature gradient between the human body and the ambient environment highlights the significant potential of flexible thermoelectric devices as self-powered energy sources for wearable electronics.However,this leaves a formidable challenge with respect to the bendability of the high-performance,yet inherently brittle,inorganic thermoelectric materials.The strategies of dislocationization and grain refinement have been reported to effectively enhance the elastic strain,thereby ensuring fully recoverable bendability for inorganic thermoelectric materials[1,2].This offers a versatile approach for enhancing the elastic bendability of inorganic thermoelectric generators.展开更多
To satisfy the requirements of practical applications,thermoelectric generators should be highly efficient and mechanically robust.Recently,progress in designing high-performance thermoelectric generators has been mad...To satisfy the requirements of practical applications,thermoelectric generators should be highly efficient and mechanically robust.Recently,progress in designing high-performance thermoelectric generators has been made.However,the mechanical properties of thermoelectric generators are still unsatisfactory.In this review,studies on the mechanical properties of thermoelectric generators are summarized.The me-chanical properties of bulk thermoelectric generators will be first discussed.In this section,the mechan-ical properties of thermoelectric materials and the strategies for improving their mechanical properties are emphasized.Since the device’s failure usually occurs at the interface between the thermoelectric ma-terials and electrode,the joint strength of electrodes and thermoelectric materials will be overviewed.After that,the mechanical properties of the inorganic thin-film thermoelectric devices will be discussed.Since the figure of merit for the flexibility of thermoelectric materials depends on the film thickness,elastic modulus,and yield strength,the synthesis methods of thin-film thermoelectric materials will be reviewed.Finally,this review will be concluded with a discussion on flexible organic thermoelectric de-vices and flexible devices using bulk legs.展开更多
With the rapid development of Internet of Things and miniaturized electronics, the demand for wearable power sources with high reliability and long duty cycle promotes the exploration of wearable thermoelectric genera...With the rapid development of Internet of Things and miniaturized electronics, the demand for wearable power sources with high reliability and long duty cycle promotes the exploration of wearable thermoelectric generators(TEGs). In particular, textile-based TEGs that can perpetually convert the ubiquitous temperature gradient between human body and ambience into electrical energy have attracted intensive attention to date.These lightweight and three-dimensional deformable TEGs comprised of fibers, filaments, yarns, or fabrics offer unique merits as wearable power source in comparison with conventional TEGs. In this review, we systematically summarize the state-of-the-art strategies for textile-based TEGs, including the structure design, fabrication, device performance, and application. Existing critical issues and future research emphasis are also discussed.展开更多
Thermoelectric generators(TEGs)are considered promising devices for waste heat recovery from various systems.The Seebeck effect can be utilized to generate power using the residual heat emitted by the filter dryer rec...Thermoelectric generators(TEGs)are considered promising devices for waste heat recovery from various systems.The Seebeck effect can be utilized to generate power using the residual heat emitted by the filter dryer receiver(FDR)of an air conditioning(A/C)system,which would otherwise go to waste.The study aims to build a set of thermoelectric generators(TEG)to collect the waste heat of the FDR and generate low-power electricity.A novel electrical circuit with two transformers is designed and fabricated to produce a more stable voltage for operation and charging.The thermoelectric generator(TEGs)was installed on the FDR of the A/C unit.The test showed that climate conditions have a significant impact on the output power generated from the system.The results showed that the peak voltage recorded in the current study is 5.2 V per day(wet,cold,and wind weather)with an output power of 0.2 W.These values are acceptable for powering the load and charging a single battery with 3.5 V as the voltage increases battery 0.1 V/20 min charge.A case study of operating the emergency signs in a building was considered.The current heat recovery system is deemed to be easily installed and can be connected to a network of TEGs to produce more power.展开更多
Our community currently deals with issues such as rising electricity costs,pollution,and global warming.Scientists work to improve energy harvesting-based power generators in order to reduce their impacts.The Seebeck ...Our community currently deals with issues such as rising electricity costs,pollution,and global warming.Scientists work to improve energy harvesting-based power generators in order to reduce their impacts.The Seebeck effect has been used to illustrate the capacity of thermoelectric generators(TEGs)to directly convert thermal energy to electrical energy.They are also ecologically beneficial since they do not include chemical products,function quietly because they lack mechanical structures and/or moving components,and may be built using different fabrication technologies such as three-dimentional(3D)printing,silicon technology,and screen printing,etc.TEGs are also position-independent and have a long operational lifetime.TEGs can be integrated into bulk and flexible devices.This review gives further investigation of TEGs,beginning with a full discussion of their operating principle,kinds,materials utilized,figure of merit,and improvement approaches,which include various thermoelectric material arrangements and utilised technologies.This paper also discusses the use of TEGs in a variety of disciplines such as automobile and biomedical.展开更多
Solid-state ionic thermoelectric generators have emerged as promising solutions for efficient harvesting of low-grade waste heat.However,the main challenge in achieving continuous power supply is the low efficiency of...Solid-state ionic thermoelectric generators have emerged as promising solutions for efficient harvesting of low-grade waste heat.However,the main challenge in achieving continuous power supply is the low efficiency of thermoelectric conversion.In this work,substantial achievements have been made in improving the thermoelectric conversion characteristics by introducing redox pairs on the electrode surfaces.This approach takes advantage of the synergistic effect of thermal diffusion and thermoelectric effects to maximize the conversion efficiency.To improve the thermoelectric storage and output power performance,Prussian blue was attached to a carbon woven fabric and used as an electrode.The incorporation of Prussian blue/carbon woven fabric electrodes results in an increase in current density output and an instantaneous power density of 3.7 mW/m^(2)·K^(2).Furthermore,under a temperature gradient of 10 K,the output energy density for 2 h is 194 J/m^(2),and the Carnot relative efficiency is as high as 0.12%at a hot side temperature(T_(H))of 30℃ and a cold side temperature(T_(C))of 20℃.Our findings validate the efficacy of integrating thermal diffusion and redox reactions in ionic thermoelectric generators,paving the way for the progress of thermocharged devices and their potential commercial applications.展开更多
Segmented thermoelectric generators(STEGs)can exhibit present superior performance than those of the conventional thermoelectric generators.Thermal and electrical contact resistances exist between the thermoelectric m...Segmented thermoelectric generators(STEGs)can exhibit present superior performance than those of the conventional thermoelectric generators.Thermal and electrical contact resistances exist between the thermoelectric material interfaces in each thermoelectric leg.This may significantly hinder performance improvement.In this study,a five-layer STEG with three pairs of thermoelectric(TE)materials was investigated considering the thermal and electrical contact resistances on the material contact surface.The STEG performance under different contact resistances with various combinations of TE materials were analyzed.The relationship between the material sequence and performance indicators under different contact resistances is established by machine learning.Based on the genetic algorithm,for each contact resistance combination,the optimal material sequences were identified by maximizing the electric power and energy conversion efficiency.To reveal the underlying mechanism that determines the heat-to-electrical performance,the total electrical resistance,output voltage,ZT value,and temperature distribution under each optimized scenario were analyzed.The STEG can augment the heat-to-electricity performance only at small contact resistances.A large contact resistance significantly reduces the performance.At an electrical contact resistance of RE=10^(-3) K⋅m^(2)⋅W^(-1) and thermal contact resistance of RT=10-8Ω⋅m^(2),the maximum electric power was reduced to 5.71 mW(90.86 mW without considering the contact resistance).And the maximum energy conversion efficiency is lowered to 2.54%(12.59%without considering the contact resistance).展开更多
Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg va...Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m−1 K−2 at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm⁻2 at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.展开更多
Organic thermoelectric generators(TEGs)are flexible and lightweight,but they often have high electrical resistance,poor output power,and low mechanical durability,because of which their thermoelectric performance is p...Organic thermoelectric generators(TEGs)are flexible and lightweight,but they often have high electrical resistance,poor output power,and low mechanical durability,because of which their thermoelectric performance is poor.We used a facile and rapid solvent evaporation process to prepare a robust carbon nanotube/Bi0.45Sb1.55Te3(CNT/BST)foam with a high thermoelectric figure of merit(zT).The BST sub-micronparticles effectively create an electrically conductive network within the three-dimensional porous CNT foam to greatly improve the electrical conductivity and the Seebeck coefficient and reinforce the mechanical strength of the composite against applied stresses.The CNT/BST foam had a zT value of 7.8×10^(−3)at 300 K,which was 5.7 times higher than that of pristine CNT foam.We used the CNT/BST foam to fabricate a flexible TEG with an internal resistance of 12.3Ωand an output power of 15.7μW at a temperature difference of 21.8 K.The flexible TEG showed excellent stability and durability even after 10,000 bending cycles.Finally,we demonstrate the shapeability of the CNT/BST foam by fabricating a concave TEG with conformal contact on the surface of a cylindrical glass tube,which suggests its practical applicability as a thermal sensor.展开更多
Nanostructured surface is a promising photon management strategy to tune spectrum in design of the selective solar absorber.In this paper,we propose a nanocone structured surface as a perfect solar absorber in applica...Nanostructured surface is a promising photon management strategy to tune spectrum in design of the selective solar absorber.In this paper,we propose a nanocone structured surface as a perfect solar absorber in application of the solar thermoelectric generators(STEGs).The trade-off between the solar absorption and the mid-infrared emission is obtained to maximize the STEG efficiency.The effects of the geometric parameters,thermal concentration,incident angle and polarized state as well as the lattice arrangement are systematically investigated.The results show that the STEGs equipped with our proposed selective solar absorber can achieve a peak efficiency of 6.53%under AM1.5G condition(no optical concentration).Furthermore,the selective solar absorber exhibits insensitive behavior to the incident angle and polarization angle as well.This means that the proposed selective solar absorber can utilize solar energy as much as possible and be generally suitable in equipping the STEGs without optical concentration.展开更多
Solar thermoelectric generators （STEGs） are heat engines which can generate electricity from concentrated sunlight. The non-uniform illumination caused by the optical concentrator may affect the performance of solar...Solar thermoelectric generators （STEGs） are heat engines which can generate electricity from concentrated sunlight. The non-uniform illumination caused by the optical concentrator may affect the performance of solar thermoelectric generators. In this paper, a three- dimensional finite element model of solar thermoelectric generators is established. The two-dimensional Gaussian distribution is employed to modify the illumination profiles incident on the thermoelectric generator. Six non-uniformities of solar illumination are investigated while keeping the total energy constant. The influences of non-uniform illumination on the temperature distribution, the voltage distribution, and the maximum output power are respectively discussed. Three thermoelectric generators with 32, 18 and 8 pairs of thermocouples are compared to investigate their capability under non-uniform solar radiation. The result shows that the non-uniformity of the solar illumination has a great effect on the temperature distribution and the voltage distribution. Central thermoelectric legs can achieve a larger temperature difference and generate a larger voltage than peripheral ones. The non-uniform solar illumination will weaken the capability of the TE generator, and the maximum output power decrease by 1.4% among the range of non-uniformity studied in this paper. Reducing the number of the thermoelectric legs for non-uniform solar illumination can greatly increase the performance of the thermoelectric generator.展开更多
Thermoelectric(TE)materials and devices have attracted great attention due to their ability to convert waste heat to electrical power and active cooling.However,the conventional bulk TE materials are inorganic semicon...Thermoelectric(TE)materials and devices have attracted great attention due to their ability to convert waste heat to electrical power and active cooling.However,the conventional bulk TE materials are inorganic semiconductors with inherent brittleness and rigidity.They cannot closely contact curved heat sources and sinks,which limits their application in modern electronics.It remains a big challenge to fabricate high-performance TE materials and devices with good flexibility.Here,we report a flexible TE device comprised of a single wall carbon nanotube(SWCNT)network and(0001)-textured Bi_(2)Te_(3)nanocrystals prepared by a magnetron sputtering technique.The unique Bi_(2)Te_(3)-SWCNT hybrid structure has a TE figure of merit(ZT)value of^0.23 at^330 K.A prototype TE device made of this hybrid gives a maximum output power density of^0.93 m W cm^(-2)under a temperature difference of 25 K at ambient temperature and shows good flexibility under bending.Our results open up a new way to the development of flexible TEs and their application in self-powered portable devices.展开更多
Thermoelectric generators(TEGs)have received increasing attention due to their potential to harvest low-grade heat energy(<100℃ )and provide power for the Internet of Things(IoT)and wearable electronic devices.Her...Thermoelectric generators(TEGs)have received increasing attention due to their potential to harvest low-grade heat energy(<100℃ )and provide power for the Internet of Things(IoT)and wearable electronic devices.Herein,a wood-based ordered framework is used to fabricate carbon nanotube/poly(3,4-ethylenedioxythiophene)(CNT/PEDOT)wood aerogel for TEG.The prepared CNT/PEDOT wood aerogel with an anisotropic structure exhibits a low thermal conductivity of 0.17 W m^(−1)K^(−1)and is advantageous to develop a sufficient temperature gradient.Meanwhile,CNT/PEDOT composites effectively decouple the relationship between the Seebeck coefficient and electrical conductivity by energy filtering effect to enhance thermoelectric(TE)output properties.The vertical TEG assembled by the CNT/PEDOT wood aerogels reveals an output power of 1.5μW and a mass-specific power of 15.48μW g^(−1)at a temperature difference of 39.4 K.Moreover,the layered structure renders high compressibility and fatigue resistance.The anisotropic structure,high mechanical performance,and rapid thermoelectric response,enabling the TEG based on CNT/PEDOT wood aerogel offer opportunities for continuous power supply to low-power electronic devices.展开更多
Flexible thermoelectric generators(FTEGs)offer a promising solution for powering wearable electronics,while their practical applications are mainly obstructed by the moderate properties of flexible thermoelectric(TE)m...Flexible thermoelectric generators(FTEGs)offer a promising solution for powering wearable electronics,while their practical applications are mainly obstructed by the moderate properties of flexible thermoelectric(TE)materials.Here,flexible Ag_(2)Se nanowire(NW)/methyl cellulose(MC)composite films were developed via facile screen-printing technology combined with cold pressing and annealing treatment,and a highest power factor of 1,641.58μW m^(-1)K^(-2)at 360 K was achieved.The reasons for the high TE performance of the Ag_(2)Se NW/MC composite films were because,after the annealing treatment,the Ag_(2)Se NWs were sintered to form conductive network structures,the crystallinity of Ag_(2)Se was markedly enhanced,and the content of insulating phase MC in the composite film was decreased.The Ag_(2)Se NW/MC composite film held appreciable flexibility,as its room-temperature power factor(1,312.08μW m^(-1)K^(-2))can retain~93%after bending for 1,000 cycles at a radius of 4 mm.Furthermore,the assembled FTEG consisting of 4 strips can generate a maximal power density of 3.51 W m^(-2)at a temperature difference of 14.1 K.Our results open an effective and large-scale strategy for fabricating high-performance flexible TE materials and energy-harvesting devices.展开更多
GeTe-based materials have attracted significant attention as high-efficiency thermoelectric materials for mid-temperature applications.However,GeTe thin-film materials with thermoelectric performances comparable to th...GeTe-based materials have attracted significant attention as high-efficiency thermoelectric materials for mid-temperature applications.However,GeTe thin-film materials with thermoelectric performances comparable to that of their bulk counterparts have not yet been reported,because of their unsatisfactory electrical and thermal properties caused by their poor crystal quality and high carrier concentration.Herein,a series of Sb-doped GeTe films and devices with remarkable thermoelectric performances are presented.These films are prepared through magnetron sputtering deposition at 553 K and exhibit a unique microstructure that consists of coarse-and fine-sized grains with high crystallization quality.The fine grains enhance the scattering associated with phonon transport and the coarse grains provide electron transport channels,which can suppress the thermal conductivity without obviously sacrificing the electrical conductivity.Moreover,Sb doping can effectively optimize the carrier concentration and increase the carrier effective mass,while introducing point defects and stacking faults to further scatter the phonon transport and decrease the thermal conductivity.Consequently,a peak power factor of 22.37μW cm−1 K−2 is obtained at 703 K and a maximum thermoelectric figure of merit of 1.53 is achieved at 673 K,which are substantially larger than the values reported in the existing literature.A flexible thermoelectric generator is designed and fabricated using Sb-doped GeTe films deposited on polyimide and achieves a maximum output power density of 2.22×103 W m−2 for a temperature difference of 300 K.展开更多
Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long pe...Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long periods of time. To overcome these limitations and achieve perpetual autonomy, an energy harvesting technique using a thermoelectric generator (TEG) coupled with storage on supercapacitors is proposed. The originality of the work lies in the presentation of a maintenance-free, robust, and tested solution, well adapted to a harsh industrial context with a permanent temperature gradient. The harvesting part, which is attached to the hot spot in a few seconds using magnets, can withstand temperatures of 200°C. The storage unit, which contains the electronics and supercapacitors, operates at temperatures of up to 80°C. More specifically, this article describes the final design of a 3.3 V 60 mA battery-free power supply. An analysis of the thermal potential and the electrical power that can be recovered is presented, followed by the design of the main electronic stages: energy recovery using a BQ25504, storage on supercapacitors and finally shaping the output voltage with a boost (TPS610995) followed by an LDO (TPS71533).展开更多
New alternatives and inventive renewable energy techniques which encompass both generation and power management solutions are fundamental for meeting remote residential energy supply and demand today, especially if th...New alternatives and inventive renewable energy techniques which encompass both generation and power management solutions are fundamental for meeting remote residential energy supply and demand today, especially if the grid is quasi-inexistent. Solar thermoelectric generators mounted on a dual-axis sun tracker can be a cost-effective alternative to photovoltaics for remote residential household power generation. A complete solar thermoelectric energy harvesting system is presented in this paper for energy delivery to remote residential areas in developing regions. To this end, the entire system was built, modeled, and then validated with the LTspice simulator software via the thermal-to-electrical analogy schemes. Valuable data in conjunction with a novel LTspice circuit were obtained, showing the achievability of analyzing transient heat transfer with the SPICE simulator; however a few of the problems to be solved remain at the practical level. Despite the unusual operation of the thermoelectric modules with the solar radiation, the simulation and measurements were in good agreement, thus validating the new modeling strategy.展开更多
Driven by rapid advances in the thermoelectric(TE)performance of organic materials,conjugated polymer thermoelectric(PTE)materials are considered ideal candidates for flexible self-powered devices because of their int...Driven by rapid advances in the thermoelectric(TE)performance of organic materials,conjugated polymer thermoelectric(PTE)materials are considered ideal candidates for flexible self-powered devices because of their intrinsic flexibility,tailored molecular structure,large-area solution processability,and low thermal conductivity.One promising application is the flexible and wearable TE devices used on the human body to convert human energy(human motion or body heat)into electricity.The self-powered character with extended functions allows PTE devices to monitor human activity or health status.In this review,we first introduce existing high-performance PTE materials and the architectures of PTE devices.Then,we focus on the progress of research on flexible self-powered devices based on PTE materials,including TE generators,TE sensors,and Peltier coolers.Finally,possible challenges in the development of PTE devices are discussed.展开更多
基金supported by the Hong Kong Polytechnic University through Projects of RCRE(Project No.1-BBEG)sponsored by the Research Grants Council of HongKong and the NationalNatural Science Foundation of China(Project No.N_PolyU513/18).
文摘Thermoelectric generators(TEGs)play a critical role in collecting renewable energy fromthe sun and deep space to generate clean electricity.With their environmentally friendly,reliable,and noise-free operation,TEGs offer diverse applications,including areas with limited power infrastructure,microelectronic devices,and wearable technology.The review thoroughly analyses TEG system configurations,performance,and applications driven by solar and/or radiative cooling,covering non-concentrating,concentrating,radiative cooling-driven,and dual-mode TEGs.Materials for solar absorbers and radiative coolers,simulation techniques,energy storage management,and thermal management strategies are explored.The integration of TEGs with combined heat and power systems is identified as a promising application.Additionally,TEGs hold potential as charging sources for electronic devices.This comprehensive review provides valuable insights into this energy collection approach,facilitating improved efficiency,reduced costs,and expanded applications.It also highlights current limitations and knowledge gaps,emphasizing the importance of further research and development in unlocking the full potential of TEGs for a sustainable and efficient energy future.
基金Foundation of Heilongjiang Bayi Agricultural University(Grant Nos.ZRCPY201916ZRCPY201817).
文摘A Solid Oxide Fuel Cell(SOFC)is an electrochemical device that converts the chemical energy of a substance into electrical energy through an oxidation-reduction mechanism.The electrochemical reaction of a solid oxide fuel cell(SOFC)generates heat,and this heat can be recovered and put to use in a waste heat recovery system.In addition to preheating the fuel and oxidant,producing steam for industrial use,and heating and cooling enclosed rooms,this waste heat can be used for many more productive uses.The large waste heat produced by SOFCs is a worry that must be managed if they are to be adopted as a viable option in the power generation business.In light of these findings,a novel approach to SOFC waste heat recovery is proposed.The SOFC is combined with a“Thermoelectric Generator and an Alkali Metal Thermoelectric Converter(TG-AMTC)”to transform the excess heat generated by both the SOFC and the TG-AMTC.The proposed TG-AMTC is evaluated using a number of performance indicators including power density,operating temperature,heat recovery rate,exergetic efficiency,energy efficiency,and recovery time.The experimental results state that TG-AMTC has provided an exergetic efficiency,energetic efficiency,and recovery time of 97%,98%,and 23%,respectively.The study proves that the proposed TG-AMTC for SOFC is an efficient method of recovering waste heat.
文摘Thermoelectric generators,with the unique ability to convert temperature gradients into electricity,have long been acknowledged as a sustainable technique for waste heat recovery.The remarkable advancements in both thermoelectric materials and devices have substantially propelled the practical applications of thermoelectric generators.The capability of generating electricity through the temperature gradient between the human body and the ambient environment highlights the significant potential of flexible thermoelectric devices as self-powered energy sources for wearable electronics.However,this leaves a formidable challenge with respect to the bendability of the high-performance,yet inherently brittle,inorganic thermoelectric materials.The strategies of dislocationization and grain refinement have been reported to effectively enhance the elastic strain,thereby ensuring fully recoverable bendability for inorganic thermoelectric materials[1,2].This offers a versatile approach for enhancing the elastic bendability of inorganic thermoelectric generators.
基金financially supported by the Shenzhen Sci-ence and Technology Program(No.KQTD20200820113045081)the State Key Laboratory of Advanced Welding and Join-ing,Harbin Institute of Technology+7 种基金the financial support from the National Natural Science Foun-dation of China(Nos.52172194,51971081)the Natural Sci-ence Foundation for Distinguished Young Scholars of Guangdong Province of China(No.2020B1515020023)the Natural Science Foundation for Distinguished Young Scholars of Shenzhen(No.RCJC20210609103733073)the Key Project of Shenzhen Funda-mental Research Projects(No.JCYJ20200109113418655)the financial support from the National Natural Sci-ence Foundation of China(No.51871081)the financial support from the National Natural Science Foundation of China(No.52101248)Shenzhen fundamental research projects(No.JCYJ20210324132808020)the start-up funding of Shenzhen,and the start-up funding of Harbin Institute of Technology(Shen-zhen).
文摘To satisfy the requirements of practical applications,thermoelectric generators should be highly efficient and mechanically robust.Recently,progress in designing high-performance thermoelectric generators has been made.However,the mechanical properties of thermoelectric generators are still unsatisfactory.In this review,studies on the mechanical properties of thermoelectric generators are summarized.The me-chanical properties of bulk thermoelectric generators will be first discussed.In this section,the mechan-ical properties of thermoelectric materials and the strategies for improving their mechanical properties are emphasized.Since the device’s failure usually occurs at the interface between the thermoelectric ma-terials and electrode,the joint strength of electrodes and thermoelectric materials will be overviewed.After that,the mechanical properties of the inorganic thin-film thermoelectric devices will be discussed.Since the figure of merit for the flexibility of thermoelectric materials depends on the film thickness,elastic modulus,and yield strength,the synthesis methods of thin-film thermoelectric materials will be reviewed.Finally,this review will be concluded with a discussion on flexible organic thermoelectric de-vices and flexible devices using bulk legs.
基金financial support from the Fundamental Research Funds for the Central Universities(2232019A3-05 and 2232019D3-11)the National Natural Science Foundation of China(No.51603036)+2 种基金Young Elite Scientists Sponsorship Program by CAST(2017QNRC001)Shanghai Sailing Program(19YF1400700)DHU Distinguished Young Professor Program
文摘With the rapid development of Internet of Things and miniaturized electronics, the demand for wearable power sources with high reliability and long duty cycle promotes the exploration of wearable thermoelectric generators(TEGs). In particular, textile-based TEGs that can perpetually convert the ubiquitous temperature gradient between human body and ambience into electrical energy have attracted intensive attention to date.These lightweight and three-dimensional deformable TEGs comprised of fibers, filaments, yarns, or fabrics offer unique merits as wearable power source in comparison with conventional TEGs. In this review, we systematically summarize the state-of-the-art strategies for textile-based TEGs, including the structure design, fabrication, device performance, and application. Existing critical issues and future research emphasis are also discussed.
文摘Thermoelectric generators(TEGs)are considered promising devices for waste heat recovery from various systems.The Seebeck effect can be utilized to generate power using the residual heat emitted by the filter dryer receiver(FDR)of an air conditioning(A/C)system,which would otherwise go to waste.The study aims to build a set of thermoelectric generators(TEG)to collect the waste heat of the FDR and generate low-power electricity.A novel electrical circuit with two transformers is designed and fabricated to produce a more stable voltage for operation and charging.The thermoelectric generator(TEGs)was installed on the FDR of the A/C unit.The test showed that climate conditions have a significant impact on the output power generated from the system.The results showed that the peak voltage recorded in the current study is 5.2 V per day(wet,cold,and wind weather)with an output power of 0.2 W.These values are acceptable for powering the load and charging a single battery with 3.5 V as the voltage increases battery 0.1 V/20 min charge.A case study of operating the emergency signs in a building was considered.The current heat recovery system is deemed to be easily installed and can be connected to a network of TEGs to produce more power.
文摘Our community currently deals with issues such as rising electricity costs,pollution,and global warming.Scientists work to improve energy harvesting-based power generators in order to reduce their impacts.The Seebeck effect has been used to illustrate the capacity of thermoelectric generators(TEGs)to directly convert thermal energy to electrical energy.They are also ecologically beneficial since they do not include chemical products,function quietly because they lack mechanical structures and/or moving components,and may be built using different fabrication technologies such as three-dimentional(3D)printing,silicon technology,and screen printing,etc.TEGs are also position-independent and have a long operational lifetime.TEGs can be integrated into bulk and flexible devices.This review gives further investigation of TEGs,beginning with a full discussion of their operating principle,kinds,materials utilized,figure of merit,and improvement approaches,which include various thermoelectric material arrangements and utilised technologies.This paper also discusses the use of TEGs in a variety of disciplines such as automobile and biomedical.
基金supported by the National Natural Science Foundation of China(no.52073066)GDAS’Project of Science and Technology Development(nos.2020GDASYL-20200102028,2020GDASYL-20200503001-06,and 2022GDASZH-2022010111)the Science and Technology program of Guangdong Province(no.2020B0101340005).
文摘Solid-state ionic thermoelectric generators have emerged as promising solutions for efficient harvesting of low-grade waste heat.However,the main challenge in achieving continuous power supply is the low efficiency of thermoelectric conversion.In this work,substantial achievements have been made in improving the thermoelectric conversion characteristics by introducing redox pairs on the electrode surfaces.This approach takes advantage of the synergistic effect of thermal diffusion and thermoelectric effects to maximize the conversion efficiency.To improve the thermoelectric storage and output power performance,Prussian blue was attached to a carbon woven fabric and used as an electrode.The incorporation of Prussian blue/carbon woven fabric electrodes results in an increase in current density output and an instantaneous power density of 3.7 mW/m^(2)·K^(2).Furthermore,under a temperature gradient of 10 K,the output energy density for 2 h is 194 J/m^(2),and the Carnot relative efficiency is as high as 0.12%at a hot side temperature(T_(H))of 30℃ and a cold side temperature(T_(C))of 20℃.Our findings validate the efficacy of integrating thermal diffusion and redox reactions in ionic thermoelectric generators,paving the way for the progress of thermocharged devices and their potential commercial applications.
基金supported by the National Natural Science Foundation of China(Grant No.:52176070).
文摘Segmented thermoelectric generators(STEGs)can exhibit present superior performance than those of the conventional thermoelectric generators.Thermal and electrical contact resistances exist between the thermoelectric material interfaces in each thermoelectric leg.This may significantly hinder performance improvement.In this study,a five-layer STEG with three pairs of thermoelectric(TE)materials was investigated considering the thermal and electrical contact resistances on the material contact surface.The STEG performance under different contact resistances with various combinations of TE materials were analyzed.The relationship between the material sequence and performance indicators under different contact resistances is established by machine learning.Based on the genetic algorithm,for each contact resistance combination,the optimal material sequences were identified by maximizing the electric power and energy conversion efficiency.To reveal the underlying mechanism that determines the heat-to-electrical performance,the total electrical resistance,output voltage,ZT value,and temperature distribution under each optimized scenario were analyzed.The STEG can augment the heat-to-electricity performance only at small contact resistances.A large contact resistance significantly reduces the performance.At an electrical contact resistance of RE=10^(-3) K⋅m^(2)⋅W^(-1) and thermal contact resistance of RT=10-8Ω⋅m^(2),the maximum electric power was reduced to 5.71 mW(90.86 mW without considering the contact resistance).And the maximum energy conversion efficiency is lowered to 2.54%(12.59%without considering the contact resistance).
基金supported by the National Natural Science Foundation of China(Nos.52073290 and 51927803)the Science Fund for Distinguished Young Scholars of Liaoning Province(No.2023JH6/100500004)the Shenyang Science and Technology Plan Project(No.23-407-3-23).
文摘Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m−1 K−2 at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm⁻2 at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.
文摘Organic thermoelectric generators(TEGs)are flexible and lightweight,but they often have high electrical resistance,poor output power,and low mechanical durability,because of which their thermoelectric performance is poor.We used a facile and rapid solvent evaporation process to prepare a robust carbon nanotube/Bi0.45Sb1.55Te3(CNT/BST)foam with a high thermoelectric figure of merit(zT).The BST sub-micronparticles effectively create an electrically conductive network within the three-dimensional porous CNT foam to greatly improve the electrical conductivity and the Seebeck coefficient and reinforce the mechanical strength of the composite against applied stresses.The CNT/BST foam had a zT value of 7.8×10^(−3)at 300 K,which was 5.7 times higher than that of pristine CNT foam.We used the CNT/BST foam to fabricate a flexible TEG with an internal resistance of 12.3Ωand an output power of 15.7μW at a temperature difference of 21.8 K.The flexible TEG showed excellent stability and durability even after 10,000 bending cycles.Finally,we demonstrate the shapeability of the CNT/BST foam by fabricating a concave TEG with conformal contact on the surface of a cylindrical glass tube,which suggests its practical applicability as a thermal sensor.
基金supported by the National Natural Science Foundation of China(Grant No.51336003)the 333 Scientific Research Project of Jiangsu Province(Grant No.BRA2011134)
文摘Nanostructured surface is a promising photon management strategy to tune spectrum in design of the selective solar absorber.In this paper,we propose a nanocone structured surface as a perfect solar absorber in application of the solar thermoelectric generators(STEGs).The trade-off between the solar absorption and the mid-infrared emission is obtained to maximize the STEG efficiency.The effects of the geometric parameters,thermal concentration,incident angle and polarized state as well as the lattice arrangement are systematically investigated.The results show that the STEGs equipped with our proposed selective solar absorber can achieve a peak efficiency of 6.53%under AM1.5G condition(no optical concentration).Furthermore,the selective solar absorber exhibits insensitive behavior to the incident angle and polarization angle as well.This means that the proposed selective solar absorber can utilize solar energy as much as possible and be generally suitable in equipping the STEGs without optical concentration.
基金This work was supported by the National Natural Science Foundation of China （Grant No.51590903）.
文摘Solar thermoelectric generators （STEGs） are heat engines which can generate electricity from concentrated sunlight. The non-uniform illumination caused by the optical concentrator may affect the performance of solar thermoelectric generators. In this paper, a three- dimensional finite element model of solar thermoelectric generators is established. The two-dimensional Gaussian distribution is employed to modify the illumination profiles incident on the thermoelectric generator. Six non-uniformities of solar illumination are investigated while keeping the total energy constant. The influences of non-uniform illumination on the temperature distribution, the voltage distribution, and the maximum output power are respectively discussed. Three thermoelectric generators with 32, 18 and 8 pairs of thermocouples are compared to investigate their capability under non-uniform solar radiation. The result shows that the non-uniformity of the solar illumination has a great effect on the temperature distribution and the voltage distribution. Central thermoelectric legs can achieve a larger temperature difference and generate a larger voltage than peripheral ones. The non-uniform solar illumination will weaken the capability of the TE generator, and the maximum output power decrease by 1.4% among the range of non-uniformity studied in this paper. Reducing the number of the thermoelectric legs for non-uniform solar illumination can greatly increase the performance of the thermoelectric generator.
基金financially supported by the Ministry of Science and Technology of China(Nos.2017YFA0700702,2016YFA0200102,and 2019QY(Y)0501)the National Natural Science Foundation of China(Nos.51571193,51402310,and 51625203)Shenyang National Laboratory for Materials Science Foundation and the Science Foundation for The Excellent Youth Scholars of Liaoning Province of China(No.2019-YQ-08)。
文摘Thermoelectric(TE)materials and devices have attracted great attention due to their ability to convert waste heat to electrical power and active cooling.However,the conventional bulk TE materials are inorganic semiconductors with inherent brittleness and rigidity.They cannot closely contact curved heat sources and sinks,which limits their application in modern electronics.It remains a big challenge to fabricate high-performance TE materials and devices with good flexibility.Here,we report a flexible TE device comprised of a single wall carbon nanotube(SWCNT)network and(0001)-textured Bi_(2)Te_(3)nanocrystals prepared by a magnetron sputtering technique.The unique Bi_(2)Te_(3)-SWCNT hybrid structure has a TE figure of merit(ZT)value of^0.23 at^330 K.A prototype TE device made of this hybrid gives a maximum output power density of^0.93 m W cm^(-2)under a temperature difference of 25 K at ambient temperature and shows good flexibility under bending.Our results open up a new way to the development of flexible TEs and their application in self-powered portable devices.
基金supported by the National Natural Science Foundation of China(No.32071714)Guangzhou Science and Technology project(No.202002030167)Guangdong Basic and Applied Basic Research Foundation(No.2019A1515110910)。
文摘Thermoelectric generators(TEGs)have received increasing attention due to their potential to harvest low-grade heat energy(<100℃ )and provide power for the Internet of Things(IoT)and wearable electronic devices.Herein,a wood-based ordered framework is used to fabricate carbon nanotube/poly(3,4-ethylenedioxythiophene)(CNT/PEDOT)wood aerogel for TEG.The prepared CNT/PEDOT wood aerogel with an anisotropic structure exhibits a low thermal conductivity of 0.17 W m^(−1)K^(−1)and is advantageous to develop a sufficient temperature gradient.Meanwhile,CNT/PEDOT composites effectively decouple the relationship between the Seebeck coefficient and electrical conductivity by energy filtering effect to enhance thermoelectric(TE)output properties.The vertical TEG assembled by the CNT/PEDOT wood aerogels reveals an output power of 1.5μW and a mass-specific power of 15.48μW g^(−1)at a temperature difference of 39.4 K.Moreover,the layered structure renders high compressibility and fatigue resistance.The anisotropic structure,high mechanical performance,and rapid thermoelectric response,enabling the TEG based on CNT/PEDOT wood aerogel offer opportunities for continuous power supply to low-power electronic devices.
基金supported by the Shuguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(22SG54)the Natural Science Foundation of Shanghai(23ZR1481100 and 21ZR-1462300)+2 种基金support from the Knut and Alice Wallenberg Foundation through the Wallenberg Academy Fellows program(grant no.KAW 2020.0196)the Swedish Research Council under project grant no.2021-03826the Swedish Energy Agency under project 46519-1.
文摘Flexible thermoelectric generators(FTEGs)offer a promising solution for powering wearable electronics,while their practical applications are mainly obstructed by the moderate properties of flexible thermoelectric(TE)materials.Here,flexible Ag_(2)Se nanowire(NW)/methyl cellulose(MC)composite films were developed via facile screen-printing technology combined with cold pressing and annealing treatment,and a highest power factor of 1,641.58μW m^(-1)K^(-2)at 360 K was achieved.The reasons for the high TE performance of the Ag_(2)Se NW/MC composite films were because,after the annealing treatment,the Ag_(2)Se NWs were sintered to form conductive network structures,the crystallinity of Ag_(2)Se was markedly enhanced,and the content of insulating phase MC in the composite film was decreased.The Ag_(2)Se NW/MC composite film held appreciable flexibility,as its room-temperature power factor(1,312.08μW m^(-1)K^(-2))can retain~93%after bending for 1,000 cycles at a radius of 4 mm.Furthermore,the assembled FTEG consisting of 4 strips can generate a maximal power density of 3.51 W m^(-2)at a temperature difference of 14.1 K.Our results open an effective and large-scale strategy for fabricating high-performance flexible TE materials and energy-harvesting devices.
基金financial support from the Ministry of Science and Technology of China(Nos.2017YFA0700702,2017YFA0700705)the National Natural Science Foundation of China(Nos.52073290,51927803)+2 种基金the Liaoning Province Science and Technology Plan Project(2022-MS-011)the Science Fund for Distinguished Young Scholars of Liaoning Province(2023JH6/100500004)the Science and Technology Plan Projects of Shenyang(No.21108901).
文摘GeTe-based materials have attracted significant attention as high-efficiency thermoelectric materials for mid-temperature applications.However,GeTe thin-film materials with thermoelectric performances comparable to that of their bulk counterparts have not yet been reported,because of their unsatisfactory electrical and thermal properties caused by their poor crystal quality and high carrier concentration.Herein,a series of Sb-doped GeTe films and devices with remarkable thermoelectric performances are presented.These films are prepared through magnetron sputtering deposition at 553 K and exhibit a unique microstructure that consists of coarse-and fine-sized grains with high crystallization quality.The fine grains enhance the scattering associated with phonon transport and the coarse grains provide electron transport channels,which can suppress the thermal conductivity without obviously sacrificing the electrical conductivity.Moreover,Sb doping can effectively optimize the carrier concentration and increase the carrier effective mass,while introducing point defects and stacking faults to further scatter the phonon transport and decrease the thermal conductivity.Consequently,a peak power factor of 22.37μW cm−1 K−2 is obtained at 703 K and a maximum thermoelectric figure of merit of 1.53 is achieved at 673 K,which are substantially larger than the values reported in the existing literature.A flexible thermoelectric generator is designed and fabricated using Sb-doped GeTe films deposited on polyimide and achieves a maximum output power density of 2.22×103 W m−2 for a temperature difference of 300 K.
文摘Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long periods of time. To overcome these limitations and achieve perpetual autonomy, an energy harvesting technique using a thermoelectric generator (TEG) coupled with storage on supercapacitors is proposed. The originality of the work lies in the presentation of a maintenance-free, robust, and tested solution, well adapted to a harsh industrial context with a permanent temperature gradient. The harvesting part, which is attached to the hot spot in a few seconds using magnets, can withstand temperatures of 200°C. The storage unit, which contains the electronics and supercapacitors, operates at temperatures of up to 80°C. More specifically, this article describes the final design of a 3.3 V 60 mA battery-free power supply. An analysis of the thermal potential and the electrical power that can be recovered is presented, followed by the design of the main electronic stages: energy recovery using a BQ25504, storage on supercapacitors and finally shaping the output voltage with a boost (TPS610995) followed by an LDO (TPS71533).
文摘New alternatives and inventive renewable energy techniques which encompass both generation and power management solutions are fundamental for meeting remote residential energy supply and demand today, especially if the grid is quasi-inexistent. Solar thermoelectric generators mounted on a dual-axis sun tracker can be a cost-effective alternative to photovoltaics for remote residential household power generation. A complete solar thermoelectric energy harvesting system is presented in this paper for energy delivery to remote residential areas in developing regions. To this end, the entire system was built, modeled, and then validated with the LTspice simulator software via the thermal-to-electrical analogy schemes. Valuable data in conjunction with a novel LTspice circuit were obtained, showing the achievability of analyzing transient heat transfer with the SPICE simulator; however a few of the problems to be solved remain at the practical level. Despite the unusual operation of the thermoelectric modules with the solar radiation, the simulation and measurements were in good agreement, thus validating the new modeling strategy.
基金supported by the National Natural Science Foundation of China(No.92263109)the Shanghai Rising-Star Program(No.22QA1410400)Natural Science Foundation of Shanghai(No.23ZR1472200).
文摘Driven by rapid advances in the thermoelectric(TE)performance of organic materials,conjugated polymer thermoelectric(PTE)materials are considered ideal candidates for flexible self-powered devices because of their intrinsic flexibility,tailored molecular structure,large-area solution processability,and low thermal conductivity.One promising application is the flexible and wearable TE devices used on the human body to convert human energy(human motion or body heat)into electricity.The self-powered character with extended functions allows PTE devices to monitor human activity or health status.In this review,we first introduce existing high-performance PTE materials and the architectures of PTE devices.Then,we focus on the progress of research on flexible self-powered devices based on PTE materials,including TE generators,TE sensors,and Peltier coolers.Finally,possible challenges in the development of PTE devices are discussed.
