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1.
Adv Sci (Weinh) ; : e2402209, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38946664

RESUMO

Zintl phases typically exhibit low lattice thermal conductivity, which are extensively investigated as promising thermoelectric candidates. While the significance of Zintl anionic frameworks in electronic transport properties is widely recognized, their roles in thermal transport properties have often been overlooked. This study delves into KCdSb as a representative case, where the [CdSb4/4]- tetrahedrons not only impact charge transfer but also phonon transport. The phonon velocity and mean free path, are heavily influenced by the bonding distance and strength of the Zintl anions Cd and Sb, considering the three acoustic branches arising from their vibrations. Furthermore, the weakly bound Zintl cation K exhibits localized vibration behaviors, resulting in strong coupling between the high-lying acoustic branch and the low-lying optical branch, further impeding phonon diffusion. The calculations reveal that grain boundaries also contribute to the low lattice thermal conductivity of KCdSb through medium-frequency phonon scattering. These combined factors create a glass-like thermal transport behavior, which is advantageous for improving the thermoelectric merit of zT. Notably, a maximum zT of 0.6 is achieved for K0.84Na0.16CdSb at 712 K. The study offers both intrinsic and extrinsic strategies for developing high-efficiency thermoelectric Zintl materials with extremely low lattice thermal conductivity.

2.
Heliyon ; 10(11): e31835, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38947454

RESUMO

During the measurement of multiphase flow in low yield oil wells, the liquid volume will vary with the operating characteristics of the pumping unit. Using the pulsating characteristics of the up and down strokes of a pumping unit, the flow rate is measured when there is a flow rate on the up stroke, and the water content is measured when the fluid is stationary on the down stroke. In this paper, the heat transfer method is used to measure the water content of the oil water mixture during the down stroke process. At this time, the water content can be expressed as the instantaneous water content of the oil well. Firstly, the feasibility of measuring water content using heat transfer method is demonstrated theoretically, and then the temperature change of the heating probe PT300 is simulated. Finally, the actual temperature of PT300 is measured experimentally. Comparing the experimental value with the simulation value, the calculated measurement error is within 1.27 %, which indicates that the heat transfer method is feasible for measuring water content. Using the same single sensor to measure oil water two-phase flow using the pulsation characteristics of the up and down strokes of a pumping unit is a major innovation in this paper. And lays a foundation for the detection of multiphase flow using heat transfer methods. The successful implementation of the text heat transfer method for measuring water content has broken the previous situation of multiple sensor detection, simplified the structure of multiphase flow instruments, and extended the life of the instrument.

3.
Discov Nano ; 19(1): 99, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38861224

RESUMO

Recently, the synthesis of oxidized holey graphene with the chemical formula C2O has been reported (J. Am. Chem. Soc. 2024, 146, 4532). We herein employed a combination of density functional theory (DFT) and machine learning interatomic potential (MLIP) calculations to investigate the electronic, optical, mechanical and thermal properties of the C2O monolayer, and compared our findings with those of its C2N counterpart. Our analysis shows that while the C2N monolayer exhibits delocalized π-conjugation and shows a 2.47 eV direct-gap semiconducting behavior, the C2O counterpart exhibits an indirect gap of 3.47 eV. We found that while the C2N monolayer exhibits strong absorption in the visible spectrum, the initial absorption peaks in the C2O lattice occur at around 5 eV, falling within the UV spectrum. Notably, we found that the C2O nanosheet presents significantly higher tensile strength compared to its C2N counterpart. MLIP-based calculations show that at room temperature, the C2O nanosheet can exhibit remarkably high tensile strength and lattice thermal conductivity of 42 GPa and 129 W/mK, respectively. The combined insights from DFT and MLIP-based results provide a comprehensive understanding of the electronic and optical properties of C2O nanosheets, suggesting them as mechanically robust and highly thermally conductive wide bandgap semiconductors.

4.
Nanomaterials (Basel) ; 14(11)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38869610

RESUMO

Crosslinked polyethylene (XLPE) is an important polyethylene modification material which is widely used in high-voltage direct current (HVDC) transmission systems. Low-density polyethylene (LDPE) was used as a matrix to improve the thermal and electrical properties of XLPE composites through the synergistic effect of a crosslinking agent and nanopore structure molecular sieve, TS-1. It was found that the electrical and thermal properties of the matrices were different due to the crosslinking degree and crosslinking efficiency, and the introduction of TS-1 enhanced the dielectric constants of the two matrices to 2.53 and 2.54, and the direct current (DC) resistivities were increased to 3 × 1012 and 4 × 1012 Ω·m, with the enhancement of the thermal conductivity at different temperatures. As the applied voltage increases, the DC breakdown field strength is enhanced from 318 to 363 kV/mm and 330 to 356 kV/mm. The unique nanopore structure of TS-1 itself can inhibit the injection and accumulation in the internal space of crosslinked polyethylene composites, and the pore size effect of the filler can limit the development of electron impact ionization, inhibit the electron avalanche breakdown, and improve the strength of the external applied electric field (breakdown field) that TS-1/XLPE nanocomposites can withstand. This provides a new method for the preparation of nanocomposite insulating dielectric materials for HVDC transmission systems with better performance.

5.
Forensic Sci Int ; 361: 112107, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38878614

RESUMO

In order to determine whether CO poisoning was the definitive cause of death, the concentration of carboxyhemoglobin (COHb) in spleen specimens was analyzed using a gas chromatography-thermal conductivity detector. 125 cases of forensic autopsy reports containing COHb analysis requests were analyzed and subdivided into two groups, improbable and highly probable of CO intoxication. In the first group which consists of 100 cases, the results of COHb analysis were negative, and the circumstances of death, as well as the postmortem findings could not validate the exposure to CO. In the second group which consists of 25 cases, the results of COHb were positive, and both postmortem findings and circumstances of death confirmed the exposure to CO. In the cases of indoors and vehicle fires or those including the use of briquettes, COHb levels reached 43.1-97.5 %, whereas in individuals without any feature of CO poisoning had COHb level high as 29.8 %. However, certain cases without any connection to fire nor CO exposure also contained significant amount of CO based on post-mortem analysis. This study focuses on cases without any relationship to fire or CO and proves that COHb levels below 30 % may be considered as a contributing factor to but not exclusively as the cause of death.

6.
Materials (Basel) ; 17(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38893783

RESUMO

Graphene has attracted much interest in many scientific fields because of its high specific surface area, Young's modulus, fracture strength, carrier mobility and thermal conductivity. In particular, the graphene oxide (GO) prepared by chemical exfoliation of graphite has achieved low-cost and large-scale production and is one of the most promising for Cu matrix composites. Here, we prepared a high strength, high electrical conductivity and high thermal conductivity reduced graphene oxide (RGO)/Cu composite by directly heating the GO/copper formate. The oxygen-containing functional groups and defects of RGO are significantly reduced compared with those of GO. The tensile yield strength and thermal conductivity of RGO/Cu composite with RGO volume fraction of 0.49 vol.% are as high as 553 MPa and 364 W/(m·K) at room temperature, respectively. The theoretical value of the tensile yield strength of the composite is calculated according to the strengthening mechanism, and the result shows that it agrees with the experimental value. After hot-rolling treatment, the ductility and conductivity of the composite materials have been greatly improved, and the ductility of the RGO/Cu composite with RGO volume fraction of 0.49 vol.% has been increased to four times the original. This work provides a highly efficient way to fabricate a high-performance RGO-reinforced Cu composite for commercial application.

7.
Materials (Basel) ; 17(11)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38893851

RESUMO

Anti-wear coatings obtained through PVD methods may significantly increase the durability of cutting tools by impacting their wear mechanisms. This study presents and discusses the results of studies on the impact of the thermal conductivity of PVD coatings on the intensity of the built-up edge (BUE) and built-up layer (BUL) formation in Inconel 600 alloy machining processes. The authors determine the microstructure, phase structure, mechanical properties (hardness, Young's modulus, and adhesion), and thermal conductivity of different PVD coatings selected for the purpose of the study and varying in terms of conductivity-i.e., AlCrTiN and AlCrTiN/BN. Machining processes were carried out under controlled conditions using VBGT160404-M3 cutting inserts with AlCrTiN and AlCrTiN/BN coatings deposited on their surface. The authors prove that the adjustment of the thermal conductivity of PVD coatings to the thermal conductivity of the tool and machined materials can help change the direction of heat flow to cool the cutting zone more effectively. The study results presented in this article show that the deposition of the AlCrTiN/BN coating reduces the friction wear on the tool flank by over 70% and lowers the intensity of BUE and BUL formation processes on the face by 10%, compared to the AlCrTiN coating.

8.
Materials (Basel) ; 17(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38893904

RESUMO

The research focuses on ultra-lightweight foam concrete with a dry density below 200 kg/m3, primarily used as insulation material. Factors that may affect material properties are categorized into mixing techniques and material composition, and experimental investigations were conducted on the impact of these factors on the rheological properties of cement slurry, density at different time intervals, compressive strength, and thermal conductivity of foam concrete samples. The experimental results indicate the influence of mixing speed and mixing duration on the instrument during the cement slurry production and mixing process with foam. Additionally, variations in foam concrete sample properties are observed due to the water-to-cement ratio, foam content, and foam density in the selected material compositions. By analyzing the material density at different time intervals, the relationship between the ambient air trapped during the mixing process and the viscosity of the material can be indirectly observed. This analysis can also reveal the correlation between the unplanned air content and the properties of the material.

9.
Materials (Basel) ; 17(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38893905

RESUMO

Ambient pressure drying (APD) of silica aerogels has emerged as an attractive method adapting to large-scale production. Spring-back is a unique phenomenon during APD of silica aerogels with volume expansion after its shrinkage under capillary force. We attribute the intense spring-back at elevated drying temperatures to a dense structure formed on the surface and the formation of positive internal pressure. Furthermore, an APD-assisted foaming method with an in situ introduction of NH4HCO3 was proposed. NH4HCO3 decomposing at drying temperatures hastened the emergence of positive pressure, thereby increasing the expansion volume. Compared to the previous method, the porosity of silica aerogel increased from 82.2% to 92.6%, and mesopore volume from 1.79 cm3 g-1 to 4.54 cm3 g-1. By adjusting the amount of the silicon source, silica aerogels prepared by the APD-assisted foaming method generated higher volume expansion and lower thermal conductivity. After calcination to remove undecomposed ammonium salts, the hydrophobic silica aerogel with a density of 0.112 g cm-3 reached a mesopore volume of 5.07 cm3 g-1 and a thermal conductivity of 18.9 mW m-1·K-1. This strategy not only improves the thermal insulation properties, but also offers a significant advancement in tailoring silica aerogels with specific porosity and mesopore volume for various applications.

10.
Materials (Basel) ; 17(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38893917

RESUMO

In a recent breakthrough in the field of two-dimensional (2D) nanomaterials, the first synthesis of a single-atom-thick gold lattice of goldene has been reported through an innovative wet chemical removal of Ti3C2 from the layered Ti3AuC2. Inspired by this advancement, in this communication and for the first time, a comprehensive first-principles investigation using a combination of density functional theory (DFT) and machine learning interatomic potential (MLIP) calculations has been conducted to delve into the stability, electronic, mechanical and thermal properties of the single-layer and free-standing goldene. The presented results confirm thermal stability at 700 K as well as remarkable dynamical stability of the stress-free and strained goldene monolayer. At the ground state, the elastic modulus and tensile strength of the goldene monolayer are predicted to be over 226 and 12 GPa, respectively. Through validated MLIP-based molecular dynamics calculations, it is found that at room temperature, the goldene nanosheet can exhibit anisotropic tensile strength over 9 GPa and a low lattice thermal conductivity around 10 ± 2 W/(m.K), respectively. We finally show that the native metallic nature of the goldene monolayer stays intact under large tensile strains. The combined insights from DFT and MLIP-based results provide a comprehensive understanding of the stability, mechanical, thermal and electronic properties of goldene nanosheets.

11.
Artigo em Inglês | MEDLINE | ID: mdl-38896498

RESUMO

The rising concern over the usage of electronic devices and the operating environment requires efficient thermal interface materials (TIMs) to take away the excess heat generated from hotspots. TIMs are crucial in dissipating undesired heat by transferring energy from the source to the heat sink. Silicone oil (SO)-based composites are the most used TIMs due to their strong bonding and oxidation resistance. However, thermal grease performance is unreliable due to aging effects, toxic chemicals, and a higher percentage of fillers. In this work, TIMs are prepared using exfoliated hexagonal boron nitride nanosheets (h-BNNS) as a nanofiller, and they were functionalized by ecofriendly natural biopolymer soy protein isolate (SPI). The exfoliated h-BNNS has an average lateral size of ∼266 nm. The functionalized h-BNNS/SPI are used as fillers in the SO matrix, and composites are prepared using solution mixing. Hydrogen bonding is present between the organic chain/oxygen in silicone polymer, and the functionalized h-BNNS are evident from the FTIR measurements. The thermal conductivity of h-BNNS/SPI/SO was measured using the modified transient plane source (MTPS) method. At room temperature, the maximum thermal conductivity is 1.162 Wm-1K-1 (833% enhancement) at 50 wt % of 3:1 ratio of h-BNNS:SPI, and the thermal resistance (TR) of the composite is 5.249 × 106 K/W which is calculated using the Foygel nonlinear model. The heat management application was demonstrated by applying TIM on a 10 W LED bulb. It was found that during heating, the 50 wt % TIM decreases the surface temperature of LED by ∼6 °C compared with the pure SO-based TIM after 10 min of ON condition. During cooling, the modified TIM reduces the surface temperature by ∼8 °C under OFF conditions within 1 min. The results indicate that natural polymers can effectively stabilize and link layered materials, enhancing the efficiency of TIMs for cooling electronics and LEDs.

12.
Artigo em Inglês | MEDLINE | ID: mdl-38914093

RESUMO

The lattice thermal conductivities (κ_"lat" ^ ) of Earth's lower mantle (LM) minerals is a crucial parameter in the study of deep Earth dynamics and its determination is also one of the grand challenges in condensed matter physics. Here, we review recent progress on theoretical and experimental studies for the κ_"lat" ^ under high pressure (P) and high temperature (T) condition up to 150 GPa and 4000 K. After the critical parameters necessary to obtain converged values of the κ_"lat" ^ are summarized, the theoretical κ_"lat" ^ of the LM minerals, determined through various computational methodologies, is compiled along with experimental findings. Although significant scattering is found in the experimental results at LM P,T, the quantum anharmonic lattice dynamics theory combined with the phonon Boltzmann transport theory demonstrates a clear relationship in the κ_"lat" ^ of the end-member LM phases, MgO, MgSiO3 bridgmanite (Brg) and post-perovskite (PPv), κ_lat^MgO>>κ_lat^PPv>κ_lat^Brg, and a discontinuous change in the κ_"lat" ^ by ~20-50% expected across the Brg-PPv transition. Knowledge on the additional but geophysically important factors, such as the effects of iron solid solution, isotopic mass difference, and higher order crystal anharmonicity are also summarized in detail. Current problems and future perspectives are finally mentioned.

13.
Artigo em Inglês | MEDLINE | ID: mdl-38910293

RESUMO

Graphene is widely used in excellent thermal interface materials (TIMs), thanks to its remarkably high in-plane thermal conductivity (k∥). However, the poor through-plane thermal conductivity (k⊥) limits its further application. Here, we developed a simple in situ growth method to prepare graphene-based thermal interface composites with positively temperature-dependent thermal conductivity, which loaded aluminum (Al) nanoparticles onto graphene nanoplatelets (GNPs). To evaluate the variations in thermal performance, we determined the thermal diffusivity and specific heat capacity of the composites using a laser-flash analyzer and a differential scanning calorimeter, respectively. The Al nanoparticles act as bridges between the nanoplatelets, enhancing the k⊥ of the 1.3-Al/GNPs composite to 11.70 W·m-1·K-1 at 25 °C. Even more remarkably, those nanoparticles led to a unique increase in k⊥ with temperature, reaching 20.93 W·m-1·K-1 at 100 °C. Additionally, we conducted an in-depth investigation of the thermal conductivity mechanism of the Al/GNPs composites. The exceptional heat transport property enabled the composites to exhibit a superior heat dissipation performance in simulated practical applications. This work provides valuable insights into utilizing graphene in composites with Al nanoparticles, which have special thermal conductivity properties, and offers a promising pathway to enhance the k⊥ of graphene-based TIMs.

14.
Materials (Basel) ; 17(12)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38930249

RESUMO

Thermal storage cement-based materials, formed by integrating phase change materials into cementitious materials, exhibit significant potential as energy storage materials. However, poor thermal conductivity severely limits the development and application of these materials. In this study, an amorphous SiO2 shell is encapsulated on a graphite surface to create a novel thermally modified admixture (C@SiO2). This material exhibits excellent thermal conductivity, and the surface-encapsulated amorphous SiO2 enhances its bond with cement. Further, C@SiO2 was added to the thermal storage cement-based materials at different volume ratios. The effects of C@SiO2 were evaluated by measuring the fluidity, thermal conductivity, phase change properties, temperature change, and compressive strength of various thermal storage cement-based materials. The results indicate that the newly designed thermal storage cement-based material with 10 vol% C@SiO2 increases the thermal conductivity coefficient by 63.6% and the latent heat of phase transition by 11.2% compared to common thermal storage cement-based materials. Moreover, C@SiO2 does not significantly impact the fluidity and compressive strength of the thermal storage cement-based material. This study suggests that C@SiO2 is a promising additive for enhancing thermal conductivity in thermal storage cement-based materials. The newly designed thermal storage cement-based material with 10 vol% C@SiO2 is a promising candidate for energy storage applications.

15.
Micromachines (Basel) ; 15(6)2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38930641

RESUMO

Among the different techniques for monitoring the flow rate of various fluids, thermal flow sensors stand out for their straightforward measurement technique. However, the main drawback of these types of sensors is their dependency on the thermal properties of the medium, i.e., thermal conductivity (k), and volumetric heat capacity (ρcp). They require calibration whenever the fluid in the system changes. In this paper, we present a single hot wire suspended above a V-groove cavity that is used to measure k and ρcp through DC and AC excitation for both pure gases and binary gas mixtures, respectively. The unique characteristic of the proposed sensor is its independence of the flow velocity, which makes it possible to detect the medium properties while the fluid flows over the sensor chip. The measured error due to fluctuations in flow velocity is less than ±0.5% for all test gases except for He, where it is ±6% due to the limitations of the measurement setup. The working principle and measurement results are discussed.

16.
Molecules ; 29(12)2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38930936

RESUMO

The thermal surface properties of graphenes and carbon materials are of crucial importance in the chemistry of materials, chemical engineering, and many industrial processes. BACKGROUND: The determination of these surface properties is carried out using inverse gas chromatography at infinite dilution, which leads to the retention volume of organic solvents adsorbed on solid surfaces. This experimental and fundamental parameter actually reflects the surface thermodynamic interactions between injected probes and solid substrates. METHODS: The London dispersion equation and the Hamieh thermal model are used to quantify the London dispersive and polar surface energy of graphenes and carbon fibers as well their Lewis acid-base constants by introducing the coupling amphoteric constant of materials. RESULTS: The London dispersive and polar acid-base surface energies, the free energy of adsorption, the polar enthalpy and entropy, and the Lewis acid-base constants of graphenes and carbon materials are determined. CONCLUSIONS: It is shown that graphene exhibited the highest values of London dispersive surface energy, polar surface energy, and Lewis acid-base constants. The highest characteristics of graphene justify its great potentiality and uses in many industrial applications.

17.
Polymers (Basel) ; 16(12)2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38931978

RESUMO

Pectin aerogels, with very low density (around 0.1 g cm-3) and high specific surface area (up to 600 m2 g-1), are excellent thermal insulation materials since their thermal conductivity is below that of air at ambient conditions (0.025 W m-1 K-1). However, due to their intrinsic hydrophilicity, pectin aerogels collapse when in contact with water vapor, losing superinsulating properties. In this work, first, pectin aerogels were made, and the influence of the different process parameters on the materials' structure and properties were studied. All neat pectin aerogels had a low density (0.04-0.11 g cm-1), high specific surface area (308-567 m2 g-1), and very low thermal conductivity (0.015-0.023 W m-1 K-1). Then, pectin aerogels were hydrophobized via the chemical vapor deposition of methyltrimethoxysilane using different reaction durations (2 to 24 h). The influence of hydrophobization on material properties, especially on thermal conductivity, was recorded by conditioning in a climate chamber (25 °C, 80% relative humidity). Hydrophobization resulted in the increase in thermal conductivity compared to that of neat pectin aerogels. MTMS deposition for 16 h was efficient for hydrophobizing pectin aerogels in moist environment (contact angle 115°) and stabilizing material properties with no fluctuation in thermal conductivity (0.030 W m-1 K-1) and density for the testing period of 8 months.

18.
Artigo em Inglês | MEDLINE | ID: mdl-38937139

RESUMO

Moiré superlattices with a robust twist proximity effect in the low-dimensional regime can facilitate nanoscale thermoelectric devices. In pristine systems, the low efficiency and lack of proficient control of thermoelectric properties impede desirable advancements in the field of energy conversion. In the present study, we demonstrate remarkable macroscopic thermoelectric response as a consequence of microscopic band structure modulation via the twist proximity in an engineered CrI3/1T-MoS2 moiré superlattice. The local twist effect, which leads to the microscopic phenomena of electron localization, results in a comprehensive electronic structure modulation. Consequently, these local effects convolute the macroscopic thermoelectric effect. Additionally, flat bands and angle-dependent metallic to semiconducting transitions are observed at 10.89, 23.41, and 30° twist angles. We correlate the observed phenomenon with the augmented spin-charge transport and interconversion via the twist proximity effect in its semiconducting phase. The estimated ultralow electronic and lattice thermal conductivities further corroborate with the observed large figure of merit and Seebeck coefficient. The maximum values of the Seebeck coefficient and figure of merit are estimated to be ∼413 µV/K and ∼4.3 at 200 K for 30° under the constant time relaxation approach. The twist-endowed outstanding thermoelectric effect in moiré superlattices with band modulation unveils a distinctive approach to establish efficient thermoelectric devices.

19.
ACS Nano ; 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38941591

RESUMO

High-performance thermal interface materials (TIMs) are highly desired for high-power electronic devices to accelerate heat dissipation. However, the inherent trade-off conflict between achieving high thermal conductivity and excellent compliance of filler-enhanced TIMs results in the unsatisfactory interfacial heat transfer efficiency of existing TIM solutions. Here, we report the graphene fiber (GF)-based elastic TIM with metal-level thermal conductivity via mechanical-electric dual-field synergistic alignment engineering. Compared with state-of-the-art carbon fiber (CF), GF features both superb high thermal conductivity of ∼1200 W m-1 K-1 and outstanding flexibility. Under dual-field synergistic alignment regulation, GFs are vertically aligned with excellent orientation (0.88) and high array density (33.5 mg cm-2), forming continuous thermally conductive pathways. Even at a low filler content of ∼17 wt %, GF-based TIM demonstrates extraordinarily high through-plane thermal conductivity of up to 82.4 W m-1 K-1, exceeding most CF-based TIMs and even comparable to commonly used soft indium foil. Benefiting from the low stiffness of GF, GF-based TIM shows a lower compressive modulus down to 0.57 MPa, an excellent resilience rate of 95% after compressive cycles, and diminished contact thermal resistance as low as 7.4 K mm2 W-1. Our results provide a superb paradigm for the directed assembly of thermally conductive and flexible GFs to achieve scalable and high-performance TIMs, overcoming the long-standing bottleneck of mechanical-thermal mismatch in TIM design.

20.
Artigo em Inglês | MEDLINE | ID: mdl-38943223

RESUMO

Se-free n-type (Bi,Sb)2Te3 thermoelectric materials, outperforming traditional n-type Bi2(Te,Se)3, emerge as a compelling candidate for practical applications of recovering low-grade waste heat. A 100% improvement in the maximum ZT of n-type Bi1.7Sb0.3Te3 is demonstrated by using melt-spinning and excess Te-assisted transient liquid phase sintering (LPS). Te-rich sintering promotes the formation of intrinsic defects (TeBi), elevating the carrier concentration and enhancing the electrical conductivity. Melt-spinning with excess Te fine-tunes the electronic band, resulting in a high power-factor of 0.35 × 10-3 W·m-1 K-2 at 300 K. Rapid volume change during sintering induces the formation of dislocation networks, significantly suppressing the lattice thermal conductivity (0.4 W·m-1 K-1). The developed n-type legs achieve a high maximum ZT of 1.0 at 450 K resulting in a 70% improvement in the output power of the thermoelectric device (7.7 W at a temperature difference of 250 K). This work highlights the synergy between melt-spinning and transient LPS, advancing the tailored control of both electronic and thermal properties in thermoelectric technology.

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