Low Thermal Conductivity Research Articles

A novel approach for solidification enhancement of phase change materials through direct contact with a boiling fluid: An experimental investigation and visualization

Due to their remarkable properties, such as high latent heat and stable temperatures during phase transitions, phase change materials (PCMs) are widely used in thermal energy storage (TES) and thermal management systems (TMSs). However, their low thermal conductivity has limited their broader application across various industries. This study experimentally explores, for the first time, the effects of injecting boiling fluid (BF) into the PCM container as a new method to enhance heat transfer during the solidification process of PCM. To this end, Paraffin wax and acetone with saturation temperature lower than paraffin’s freezing point are selected as PCM and BF, and the influence of four various parameters, namely the initial PCM temperature (75, 85, and 95 °C), the height of the PCM inside the container (15 cm, 25 cm, and 35 cm), the flow rate of the BF (0.32, 0.46, and 0.57 L/min), and the nozzle diameter (2 mm, 3 mm, and 4 mm), on the solidification behavior of PCM, temperature distribution inside the container, and heat transfer enhancement (released energy and Nusselt number) is thoroughly scrutinized. In order to visualize and further evaluate the two simultaneous phase transitions (vaporization of the BF and solidification of the PCM), a Hele-Shaw cell with a height, width, and thickness of 50, 20, and 1 cm is considered as the PCM storage system. The findings indicate that when the BF is injected into the paraffin storage, the high heat transfer coefficient of boiling superbly improves the thermal behavior of PCM, and the solidification process occurs in a much shorter time. Also, boiling of the acetone inside the container and its direct contact with paraffin leads to a significant mixing inside the container and the creation of vortices and turbulent flow in the system, which further improves the freezing phenomenon. Furthermore, it was observed that regardless of other parameters, the flow rate of BF is the most crucial parameter, and after that, the height of the paraffin and the initial temperature have the greatest impact. By employing the highest flow rate, the proposed technique is capable of freezing 0.7, 0.5, and 0.3 L of paraffin in 48, 33, and 18 s, respectively, indicating multiple times of improvement in the full solidification time compared to previous studies.

Analysis of charging performance of thermal energy storage system with graded metal foam structure and active flip method

The latent heat thermal energy storage (LHTES) technology based on solid-liquid phase change material (PCM) is characterized by high energy storage density, small volume change, and constant operation temperature, which is widely employed in waste heat recovery, solar thermal utilization, and equipment thermal management. This paper introduces active flipping and graded porous to strengthen natural convection and heat conduction to alleviate the issue of low thermal conductivity and non-uniform phase change of PCM. Based on the fixed grid system, the enthalpy-porosity method combined with time-dependent gravity and non-Darcy porous effect is employed to solve the solid-liquid phase change problem under different porosity gradients, dimensionless flipping times (t*), and modified Ra (Ra*) numbers. Furthermore, the effects of the Ra* on the optimal t* and porosity gradient are also discussed. The results show that the flipping method can significantly enhance flow and heat transfer within the container, improve temperature field uniformity, and increase the proportion of latent heat storage. With the increase of porosity gradient and t*, the melting time initially decreases and then increases and the optimal thermal performance is achieved at a 6 % porosity gradient and t* = 0.4. Compared to the uniform porous structure without flipping, it can shorten melting time by 49.37 % and improve thermal energy storage rate (TESR) by 76.23 %. Additionally, the optimal porosity gradient is 6 % under different Ra*, but the optimal t* decreases with the increase of Ra*. This paper explores the charging performance of the thermal energy storage system with the graded metal foam structure and active flip method, which can contribute to the study of heat transfer enhancement in LHTES technology.

CMAS resistance characteristics of Gd2(Hf0.7Ce0.3)2O7 thermal barrier material at 1300 °C and 1400 °C

The corrosion resistance to calcium‑magnesium‑aluminum-silicate (CMAS) is a key property affecting the long-term durability of thermal barrier coatings (TBCs). Meanwhile, rare-earth hafnates are considered promising TBC candidates due to their low thermal conductivity and suitable thermal expansion coefficients. Thus, this study explores the CMAS corrosion resistance of Gd2(Hf0.7Ce0.3)2O7 (GH7C3) ceramic material under different conditions and compares it with the binary system Gd2Hf2O7 (GH) ceramic material. The findings indicate that GH7C3 can react chemically with CMAS and rapidly form a dense apatite crystalline layer at the interface between GH7C3 ceramic and CMAS, providing excellent CMAS resistance. Furthermore, the composition of the remaining CMAS melt Furthermore, the composition of the remaining CMAS melt undergoes compositional changes upon interaction, ultimately forming spinel in Mg and Al-enriched regions. In the meantime, CeO2 can promote the rapid formation of apatite crystals, significantly enhancing the CMAS resistance of GH7C3 to CMAS at high temperatures compared to GH.

The thermal conductivity of 3D network reinforced polypropylene matrix composites was constructed by the pickering‐like emulsion method

AbstractPolypropylene (PP) has the advantages of corrosion resistance, easy processing, and low dielectric loss, but its low thermal conductivity limits the application of its composites in fields such as electronic packaging. To solve this problem, in this work, composite microspheres with the segregated structure were prepared by coating boron nitride nanosheets (BNNSs) on the PP surface by Pickering‐like emulsion method, and BNNSs@PP composites with three‐dimensional thermal conductivity network were obtained after molding. Due to the high thermal conductivity of BNNSs and the formation of perfect thermal conduction pathways, the thermal conductivity of the composites reached 1.71 W m−1 K−1 when the content of BNNSs was 10.1 wt%, which was a 713% increase in thermal conductivity for that of pure PP. At the same time, the mechanical properties of the composites were ensured. This method provides a simple and effective technique to improve the thermal conductivity of PP‐based thermally conductive composites, which has a wide application potential in electronic packaging.

Magnetocaloric effect of topological excitations in Kitaev magnets

Traditional magnetic sub-Kelvin cooling relies on the nearly free local moments in hydrate paramagnetic salts, whose utility is hampered by the dilute magnetic ions and low thermal conductivity. Here we propose to use instead fractional excitations inherent to quantum spin liquids (QSLs) as an alternative, which are sensitive to external fields and can induce a very distinctive magnetocaloric effect. With state-of-the-art tensor-network approach, we compute low-temperature properties of Kitaev honeycomb model. For the ferromagnetic case, strong demagnetization cooling effect is observed due to the nearly free Z2 vortices via spin fractionalization, described by a paramagnetic equation of state with a renormalized Curie constant. For the antiferromagnetic Kitaev case, we uncover an intermediate-field gapless QSL phase with very large spin entropy, possibly due to the emergence of spinon Fermi surface and gauge field. Potential realization of topological excitation magnetocalorics in Kitaev materials is also discussed, which may offer a promising pathway to circumvent existing limitations in the paramagnetic hydrates.

Fly ash-based zeolite/reduced graphene oxide/polymer anti-corrosion coatings for efficient heat dissipation

Industries are demanding more and more for the high corrosion protection and thermal conductivity of organic coatings. However, organic coatings always have low thermal conductivity, and the effective distribution of inorganic particles within these organic coatings remains imperative for further enhancing both anti-corrosion and thermal conductivity capabilities simultaneously. Herein, a novel method is introduced for the exfoliation of reduced graphene oxide (rGO) through wet ball milling, incorporating fly ash-based zeolites. The resulting particles (A-rGO) formed two structures: rGO sheets wrapped around or partially loaded on the surface of zeolite particles. Notably, the absolute zeta potential of A-rGO measures 47.8, marking a 4.26-fold increase compared to rGO, thereby facilitating enhanced dispersion within the coating matrix. Then, benzoxazine/A-rGO based coatings are made, which formed a thermally conductive pathway and constructed an anti-corrosion barrier. The results showed that the highest thermal conductivity of the prepared coating (A-r-2) was as high as 1.561 W·m−1 K−1, which was 676.1 % higher than that of benzoxazine based coating, and 159.7 % higher than that of the same content of benzoxazine/rGO coating. Furthermore, the low-frequency impedance value of the A-r-2 coating reached 2.433 × 109 Ω·cm2 with a water contact angle as high as 129.8 ± 0.2°. The particles designed in this study provides a new system additive for fabricating highly thermally conductive composite coatings with high corrosion resistance.

Axial compressive behavior of partially encased composite reactive powder concrete columns after high-temperature exposure

Replacing ordinary concrete in partially encased concrete (PEC) columns with high-strength and durability reactive powder concrete (RPC) significantly improves their axial capacity and suppresses local buckling of the steel section. To study the axial mechanical performance of partially encased composite reactive powder concrete (PEC-RPC) columns after exposure to high temperatures, axial compression tests of eight PEC-RPC column specimens were designed and conducted. Thermal response, failure modes, axial load-vertical displacement curves, and strain-axial strain curves of different specimens were observed considering the effects of link spacing, cross-sectional dimensions, constant temperature duration, and cooling methods. Results indicate: PEC-RPC columns exhibited whitening on the surface of RPC after high-temperature exposure, specimens with the largest link spacing experienced RPC peeling due to concentrated thermal stress, exacerbated by spraying water, which created a stress difference between the surface and the interior, resulting in RPC peeling. The deeper the thermocouple was embedded, the lower the measured temperature. Additionally, due to the significantly lower thermal conductivity of RPC compared to steel, the temperature at measurement points within the RPC is much lower than that at the steel web. The failure mode of PEC-RPC columns after axial loading was characterized by the crushing of RPC and local buckling of section steel. The larger the link spacing, the more prone it was to multi-layer buckling, and columns with larger cross-sectional sizes tended to exhibit shear failure. The characteristic value of mechanical performance showed higher sensitivity to cross-sectional dimensions, but relatively lower sensitivity to link spacing and constant temperature duration. As the cross-sectional dimensions increased from 150×150 mm to 250×250 mm, the peak load, residual bearing capacity, stiffness, and ductility increased by 72.51–164.86 %, 89.8–173.6 %, 61.85–151.47 %, and 13.72–31.46 %, respectively. Finally, based on partition constraint theory and superposition principle, a simplified method for calculating the axial mechanical performance of PEC-RPC columns after exposure to high temperatures was proposed.

Excellent thermoelectric performance of Fe2NbAl alloy induced by strong crystal anharmonicity and high band degeneracy

Full-Heusler alloys with earth-abundant elements exhibit high mechanical strength and favorable electrical transport behavior, but their high intrinsic lattice thermal conductivity limits potential thermoelectric application. Here, the thermoelectric transport properties of Fe-based Full-Heusler Fe2MAl (M = V, Nb, Ta) alloys are comprehensively investigated utilizing density functional theory. The results suggest that Fe2NbAl exhibits exceptionally low lattice thermal conductivity due to low phonon velocities and weakly bound Nb atoms. In Fe2NbAl, the underbonding of the Nb atoms leads large Grüneisen parameters and high anharmonic scattering rates of low-frequency acoustic phonon. Meanwhile, the high band degeneracy and large electrical conductivity lead to a maximum p-type power factor of 255.6 μW·K−2·cm−1 at 900 K. The combination of low lattice thermal conductivity and favorable electrical transport properties leads a maximum p-type dimensionless figure of merit of 1.7. Our work indicates Fe2NbAl, as a low-cost, environmentally friendly, is a potential high-performance p-type thermoelectric material.

Preparation of a High-Expansion-Ratio Blend Foam with Low Thermal Conductivity Using Poly(vinyl alcohol)-Polycaprolactone Mixture Solution via Supercritical Carbon Dioxide Foaming Technology

Preparation of a High-Expansion-Ratio Blend Foam with Low Thermal Conductivity Using Poly(vinyl alcohol)-Polycaprolactone Mixture Solution via Supercritical Carbon Dioxide Foaming Technology

Experimental performance analysis of methanol adsorption in granular activated carbon packed bed through design of a double pipe heat exchanger with longitudinal fins

Activated carbon (AC) is essential for its exceptional adsorption properties and high surface area in various applications. Adsorption/desorption (A/D) processes with AC can be exothermic or endothermic, necessitating improved heat exchanger (HE) designs due to AC's low thermal conductivity. This study presents an A/D HE design with longitudinal fins in the sorption bed to enhance heat transfer during methanol A/D in AC. Bed heating/cooling uses water flowing through pipes inside the HE. Experimental investigations focus on thermal characteristics and A/D efficiency under diverse conditions, comparing results to a base non-finned HE design. Various experiments measured HE shell temperatures at different water flow rates while varying the sorption bed condition (vacuumed, filled with air, or methanol). The finned HE design showed a 1.8 °C increase in maximum bed surface temperature and a 3-h, 40-min reduction in process time compared to the non-finned HE. Subsequent tests with the finned HE at different water flow rates (5, 10, and 15 l/min) demonstrated superior heat transfer at 15 l/min due to turbulent flow enhancement. Additionally, adsorption ceased at a bed temperature of 54 °C. These findings highlight the efficacy of finned HE for optimizing methanol A/D processes, offering insights into improving heat transfer in AC-based systems.

Lightweight, compressible, elastic resorcinol-formaldehyde aerogels with cobalt-ligand-enhanced cross-linked skeletons

Resorcinol-formaldehyde (RF) aerogel materials exhibit remarkable properties such as low density, ablation resistance (high residual carbon rate), easily regulated pore structure and low thermal conductivity, making them promising for applications in adsorption, medicine and aerospace, among others. However, since their inception, RF aerogels have suffered from disadvantages such as brittleness and long preparation cycles, which have severely limited their widespread use. In order to improve the mechanical properties of RF aerogels, this paper presents a new synthetic route for obtaining strong elastic properties without introducing additional fiber reinforcement. Here, a lightweight, compressible, elastic resorcinol-formaldehyde aerogel with cobalt-ligand-enhanced cross-linked skeletons was prepared by sol-gel and freeze-drying methods using an alkali metal salt (cobalt (II) acetate) as a cross-linking agent and sodium acetate as a catalyst. The coordination of metal ions (Co2+) with resorcinol resulted in the formation of a structure analogous to a metal-phenolic network (MPN), which altered the crosslinking mode and degree of crosslinking of the RF aerogel. This process led to the thickening of the skeletal structure of the sample. Concurrently, a multilayered pore structure was generated within the interior under the appropriate pH conditions, which contributed to the strengthening of the skeleton of the samples and a reduction in thermal conductivity. The obtained RF-Co aerogel can withstand 68.6 % compression change without fracture and shows good elastic deformation at 35 % compression rate, while the aerogel exhibits low thermal conductivity (0.039 W (m K)−1) and low density (0.09 g cm−3).

Optimization of thermoelectric properties for microwave sintered Fe-doped ZnO

ZnO is a promising thermoelectric ceramic material, but the low electrical conductivity and high thermal conductivity restrict its satisfactory thermoelectric performance. Chemical doping is an effective way to improve the thermoelectric properties of ZnO. Due to the valence states and similar ionic radii of Fe3+ and Zn2+, Fe was selected as the effective dopant for ZnO. In this work, Fe-doped ZnO samples were prepared using hydrothermal synthesis and microwave sintering technology under oxygen-depleted conditions. The electrical conductivity of sintered Fe-doped ZnO was greatly improved owing to the energy band adjustment. The maximum power factor of 3108 μW/mK2 at 800 K was obtained from Zn0.997Fe0.003O, which is about 4.4 times greater than that of pure ZnO. Meanwhile, the small grain size (300–500 nm) and residual pores resulted from microwave rapid sintering in an oxygen-depleted environment, as well as the point defects caused by Fe3+ substituting for Zn2+, significantly reduced the thermal conductivity. Finally, the highest ZT value of 0.91 has been achieved in Zn0.997Fe0.003O at 800 K.

AsTe3: A novel crystalline semiconductor with ultralow thermal conductivity obtained by congruent crystallization from parent glass

The synthesis of novel narrow-band-gap semiconductors with ultralow thermal conductivity opens a pathway to the design of functional materials with high thermoelectric performance or with interesting optical sensitivity in the infrared range. Here, we report on the discovery of the novel crystalline binary AsTe3 (c-AsTe3) prepared by spark plasma sintering (SPS) from full and congruent crystallization of amorphous AsTe3 (a-AsTe3) previously prepared by twin roller quenching. X-ray diffraction suggests that the structure of c-AsTe3 can be described as a superstructure of elementary Te with a specific distribution of As and Te atoms. More specifically, it appears as an intergrowth of a Te subunit (3 atoms) and As2Te5 subunit (6 As + 15 Te atoms) separated with interlayer spaces. The optical transmittance measured on both crystalline and amorphous AsTe3 indicates a maximum transmittance of 22 % over the infrared range 10–25 µm. Transport properties measurements, performed between 5 and 375 K, reveal that AsTe3 behaves as a lightly doped, p-type semiconductor. The complex crystal structure combined with a small-grain-size microstructure of the sample yields extremely low lattice thermal conductivity values of 0.35 W m−1 K−1 near 300 K. This poor ability to conduct heat is the main property that gives rise to an estimated dimensionless thermoelectric figure of merit ZT of ∼0.3 at 375 K. These findings show that the recrystallization of amorphous phases by SPS provides an effective approach for stabilizing novel phases with interesting functional properties.

Hierarchical Incorporation of Reduced Graphene Oxide into Anisotropic Cellulose Nanofiber Foams Improves Their Thermal Insulation.

Anisotropic cellulose nanofiber (CNF) foams represent the state-of-the-art in renewable insulation. These foams consist of large (diameter >10 μm) uniaxially aligned macropores with mesoporous pore-walls and aligned CNF. The foams show anisotropic thermal conduction, where heat transports more efficiently in the axial direction (along the aligned CNF and macropores) than in the radial direction (perpendicular to the aligned CNF and macropores). Here we explore the impact on axial and radial thermal conductivity upon depositing a thin film of reduced graphene oxide (rGO) on the macropore walls in anisotropic CNF foams. To obtain rGO films on the foam walls we developed liquid-phase self-assembly to deposit rGO in a layer-by-layer fashion. Using electron and ion microscopy, we thoroughly characterized the resulting rGO-CNF foams and confirmed the successful deposition of rGO. These hierarchical rGO-CNF foams show lower radial thermal conductivity (λr) across a wide range of relative humidity compared to CNF control foams. Our work therefore demonstrates a potential method for improved thermal insulation in anisotropic CNF foams and introduces versatile self-assembly for postmodification of such foams.

Rapid and inexpensive synthesis of liter-scale SiC aerogels

Ceramic aerogels are promising materials for thermal insulation and protection under harsh environments. Yet current synthesis methods fail to provide an energy-, time-, and cost-effective route for high-throughput production and large-scale applications, especially for non-oxide ceramic aerogels. Here we reported a way to synthesize SiC aerogels within seconds and over liter scale, with a demonstrated throughput of ~16 L min−1 in a typical lab experiment. The key lies in renovated combustion synthesis and a fast expansion from powder reactants to aerogel products over 1000% in volume. The synthesis process is self-sustainable and requires minimal energy input. The product is very cheap, with an estimated price of ~$0.7 L−1 (~$7 kg−1). The obtained SiC aerogels have excellent thermo-mechanical properties, including low thermal conductivity, high elasticity, and damage tolerance. Our invention not only offers a practical pathway for large-scale applications of ceramic aerogels, but also calls for rethinking of combustion synthesis in one-step conversion from raw chemicals to bulk products ready for practical applications.

Mechanism and structure of micro-nanofluid directional heat conduction in asphalt pavement in plateau permafrost regions

Solar radiation in plateau permafrost regions is strong. The asphalt pavement strongly absorbs and slowly dissipates heat, leading to significant heat accumulation on the pavement. This accumulation disturbs the underlying permafrost and eventually causes serious pavement damage. To improve the heat resistance and dissipation capabilities of asphalt pavement, a nanofluid directional heat conduction structure (N-DHCS) was suggested and analyzed in this paper. The designed structure can resist heat in the daytime due to the low thermal conductivity of liquid and dissipates heat at night through natural convection. The finite element method and laboratory irradiation experiment were employed to performed thermal analyses of N-DHCS. The results demonstrated that establishing the N-DHCS in asphalt pavements can enhance active heat dissipation capacity, which is beneficial for protecting the frozen soil in plateau permafrost regions.

Exploring the Thermal and Ionic Transport of Cu+ Conducting Argyrodite Cu7PSe6

AbstractUnderstanding the origin of low thermal conductivities in ionic conductors is essential for improving their thermoelectric efficiency, although accompanying high ionic conduction may present challenges for maintaining thermoelectric device integrity. This study investigates the thermal and ionic transport in Cu7PSe6, aiming to elucidate their fundamental origins and correlation with the structural and dynamic properties. Through a comprehensive approach including various characterization techniques and computational analyses, it is demonstrated that the low thermal conductivity in Cu7PSe6 arises from structural complexity, variations in bond strengths, and high lattice anharmonicity, leading to pronounced diffuson transport of heat and fast ionic conduction. It is found that upon increasing the temperature, the ionic conductivity increases significantly in Cu7PSe6, whereas the thermal conductivity remains nearly constant, revealing no direct correlation between ionic and thermal transport. This absence of direct influence suggests innovative design strategies in thermoelectric applications to enhance stability by diminishing ionic conduction, while maintaining low thermal conductivity, thereby linking the domains of solid‐state ionics and thermoelectrics. Thus, this study attempts to clarify the fundamental principles governing thermal and ionic transport in Cu+‐superionic conductors, similar to recent findings in Ag+ argyrodites.

Phase change material properties identification for the design of efficient thermal management system for cylindrical Lithium-ion battery module

Performance and life of Lithium-ion battery packs in EVs and energy storage applications are limited by the thermal profile of cells during its life. Passive cooling technique based on Phase Change Material (PCM) is employed for mitigating thermal issues associated with Lithium-ion cells. The challenge with PCM materials is the trade-off between its latent heat of fusion, thermal conductivity and specific heat. Detailed CFD analysis is carried out to study the impact of PCM thermal properties on battery pack thermal profile and provide guidelines for PCM properties selection and usage of existing PCM materials. Impact of critical PCM properties such as latent heat (100–250 kJkg−1), thermal conductivity (0.2–23 Wm−1K−1), melting temperature and thickness of PCM material on thermal performance of a battery module during rapid discharge rate of 25 A (3.2C) is investigated. Battery module maximum temperature (Tmax) reaches 54°C and temperature difference (∆T) to 5.5°C while operating at 35°C with 124 kJkg−1and 0.2 Wm−1K−1. It is found that, PCM with higher latent heat (≥ 175 kJkg−1), thermal conductivity (≥ 3 Wm−1K−1), PCM thickness (≥ 3 mm) and appropriate phase change temperature 41-44°C exhibit improved heat dissipation for high discharge rates by effectively reducing the Tmax to 44.4°C and ∆T to 2.4°C (25 A and 35°C ambient). Further, ways to mitigate low latent heat capacity and thermal conductivity of PCM through increasing PCM material usage (i.e. inter cell distance) is emphasized. Results of the present study can be considered as a design tool for PCM development engineers which could be cost effective both in-terms of development time and effort.

Six‐principal‐component high‐entropy carbonitride aerogel thermal insulator: Theoretical and experimental studies

AbstractA combined theoretical and experimental approach was used to investigate high‐entropy carbonitride. Density functional theory (DFT) calculations suggest that the [N]/([C]+[N]) ratio in (Ti1/6Cr1/6V1/6Mo1/6Nb1/6Ta1/6)(C1−xNx) affects its lattice thermal conductivity which could be decreased by 89% by increasing the ratio from 0 to 1/2. Moreover, a robust, flame‐retardant and high‐temperature resistant (Ti1/6Cr1/6V1/6Mo1/6Nb1/6Ta1/6)(C0.64N0.36) high‐entropy carbonitride aerogel (6‐HECNA) was synthesized. It exhibited a porosity of 94.3%, a compressive strength of 0.9 MPa, and a good high‐temperature stability up to 1673 K. These properties, along with its outstanding fire‐retardancy, and low thermal conductivity (0.122 W·m−1·K−1 at 298 K), make it a promising candidate material for thermal insulation applications under harsh conditions.

Influence of pressure on the different physical features of lead-free double perovskite materials K2SnX6 (X = Cl, and Br): DFT replication

The influence of pressure (0–12 GPa) on several physical features of perovskite materials K2SnX6 (X = Cl, and Br) has been executed through DFT replication coded with CASTEP. Very close relation is noticed concerning the studied and synthesized lattice parameters. The studied compounds are mechanically stable under pressure according to Born's stability criteria. The Pugh's and Poisson's ratios indicate the brittle nature K2SnCl6 at 0 GPa and ductile nature at above 2 GPa. On the other hand, the phase K2SnBr6 exhibits ductile in nature at 0 GPa to high pressure. The increasing behaviors of machinable index with increasing pressure making these materials effectively useable in industrial applications. The determined Vickers hardness (Hv) values at several pressures of both the phases did not exceed 8 GPa which enables them to be more machinable and damage-tolerant. The decrease of band gap with increasing pressure ensures the probable application of these materials in optoelectronic devices. The bond length decreases with increasing pressure and consequently materials become harder. As the static dielectric constant of K2SnBr6 is higher than K2SnCl6, hence K2SnBr6 is more suitable for optoelectronic device applications. In the ultraviolet region, both the materials show their intense peak of absorption and conductivity. Both the studied compounds processes very low thermal conductivity in the entire pressure ranges comparing to the well-known thermal barrier coating (TBC) materials ABO3 which confirming their better uses in industry as TBC materials. Having very high melting temperature at high pressure these compounds are suitable for high-temperature application purposes.