Thermal Conductivity Of Phase Change Materials Research Articles

Experimental and numerical investigations of an open-cell copper foam (OCCF)/phase change material (PCM) composite-based module for satellite avionics thermal management in a thermal vacuum chamber (TVC)

Small satellites' thermal control in the space environment is crucial. Phase change materials (PCM) are promising options for satellite thermal management in space thermal conditions. The current work provides an experimental and numerical investigation of a thermal control module (TCM) using an open-cell copper foam (OCCF)/PCM combination. The experimental tests were carried out in a thermal vacuum chamber (TVC), which simulated the vacuum space environment. The PCM thermal conductivity was boosted using OCCF and aluminium fins. The metallic parallel fins divided the heat sink into six cuboid cavities and were filled with PCM. Two samples with different pores per inch (PPI) of OCCF were adopted, one with 10 PPI and the other with 20 PPI. For the experimental work, the adopted PCM was SP 31. Two levels of heating loads were applied to the TCM: 10 W and 7 W. The numerical model was verified using the experimental work findings. The experimental work concluded that the PCM capsulation sealing is a dominant factor for successful capsule design under vacuum operation. The thermal conductivity enhancers (TCEs) remarkably improved the thermal management performance of the PCM. The case with PCM reported a reduction in the maximum temperature by about 43.67 % and 41.4 % at 7 W and 10 W, respectively, relative to the case without PCM. The PCM/fins combination could improve the PCM performance and mitigate the maximum temperature from 41.7 °C to 39.6 °C with a reduction percentage of 5 %. The OCCF reported better thermal performance than the metallic fins. The OCCF with 10 PPI decreased the PCM maximum temperature by 10.3 %. The OCCF with 20 PPI reported a reduction in the PCM maximum temperature by 13.8 % at 10 W heating power.

Numerical study on using multichannel tube and PCM for improving thermal and electrical performance of a photovoltaic module

The electrical efficiency of a crystalline silicon module drops with increasing cell temperature. Phase change material (PCM) was commonly used to perform the thermal management of a PV module, while its poor thermal conductivity may act as a barrier to wide application. In the current study, an innovation design that utilizes excellent heat storage capacity (HSC) of PCM and high thermal conductivity of multichannel tube is introduced into a PV module (MPCM-PV). Computational Fluid Dynamics (CFD) modeling of the MPCM-PV together with experimental validation was conducted. It was determined that the established model can predict the performance of the MPCM-PV at reasonable accuracy. The effect of the structural and physical parameters on the operating performance of the MPCM-PV module was analyzed. The electric energy production was increased by 4.75 % when the number of channels was increased from 1 to 5. Additionally, the rectangular-shape channel rather than triangular shape was more beneficial for the MPCM-PV temperature reduction. Further, it was found that the low melting point and large HSC of PCM lead to the higher electric energy production. The electrical energy increments of 1.71 % and 0.32 % were respectively achieved when the HSC was increased from 240 kJ/kg to 560 kJ/kg and the melting temperature was decreased from 44 °C to 38 °C. The sensitive analysis suggested that the channel shape and the HSC have the most significant impact on electric energy production. These findings provide insight into the design the MPCM-PV system and can guide the development of efficient PV system.

Experimental assessment on the thermal control performance of composite phase change material for fast charging power module

The broader introduction of electric vehicles requires an improvement of battery technology or a more extensive charging infrastructure setup. In order to solve the thermal control problem of high power fast charging piles, the novel thermal control method combining liquid cooling and a small amount of composite phase change materials covered on the upper surface of the charging power module is proposed. An experimental study on the temperature rise and temperature uniformity of the power module surface is compared with single liquid cooling. Results show that adding a small amount of composite phase change material can keep its maximum temperature in the allowable operating range and make temperature uniform around the power module surface compared to the reference solution. The addition of composite phase change materials with a filling thickness of 3 mm gives an overall temperature decrease of 15.531 °C. Compared to the single liquid cooling, increasing the liquid flow rate or decreasing the liquid initial temperature will weaken the further thermal control improvement on the power module. The addition of composite phase change material can effectively keep its maximum temperature in the operating range for the fast charging pile under the larger heat generation power. The phase transition temperature of 52 °C is recommended because of the minimal temperature peak of the power module is obtained. Increasing the composite phase change material thermal conductivity from 6.05 W·m−1·K−1 to 8.99 W·m−1·K−1 will reduce the maximum temperature of the power module by 5.88 %. However, the temperature rise process of the power module suggests that the heat dissipation is mainly determined by the liquid cooling, and very low heat dissipation through the conduction and radiation of composite phase change materials. A slower temperature rise in the latent heat absorption process is observed as increasing the composite phase change material filling thickness, but no significant reduction in the temperature rise is found in the operating time of 15 min. The benefit of using the composite phase change material is reduced by 7.71 % as the cycle times are given as 100. Developing the more effective and stable composite phase change material or replacing the composite phase change materials at regular intervals is needed to ensure its effectiveness for the thermal control performance of the fast charging power module. The present research works show very promising results on the limited researches on the cooling scheme of power devices in higher current fast charging piles.

Thermal Balance of a Water Thermal Accumulator Based on Phase Change Materials

The arrangement of a water thermal accumulator (WTA) containing phase change materials (PCM) is presented and analyzed. The hot or cool water is used as a working body. The accumulator contains two concentric cylindrical tubes. The inner tube is used for hot or cool water flowing, while the volume between the inner and outer tubes is filled with PCM. The thermal energy in the accumulator is stored as a result of flowing the hot water through the inner tube due to the phase transition in PCM. This accumulated energy can be extracted from PCM as a result of flowing the cool water through the inner tube. For the enhancement of the thermal conduction coefficient, the PCM is doped with the nanocarbon particles having a thermal conductivity coefficient exceeding that of PCM by 4–5 orders of magnitude. The thermal balance of the accumulator is calculated on the basis of the solution of the time-dependent heat conduction equation by taking into account the heat absorbed and released as a result of the phase transition as well as the convection thermal exchange in the melted PCM. The calculation results determine the interconnection between the thermal conductivity of PCM and the characteristic time of thermal exchange between PCM and the working body. The calculations indicate that the characteristic thermal exchange time decreases as the thermal conduction coefficient enhances, so that the dependence becomes close to saturation at the thermal conductivity coefficient of about 5 W/m K. Such a coefficient can be reached by doping the paraffin-based PCM with a reduced graphene oxide at a content of about 2% (weight).

Surface-Modified Compressed Expanded Graphite for Increased Salt Hydrate Phase Change Material Thermal Conductivity and Stability

Surface-Modified Compressed Expanded Graphite for Increased Salt Hydrate Phase Change Material Thermal Conductivity and Stability

Energy storage potential analysis of phase change material (PCM) energy storage units based on tunnel lining ground heat exchangers

Low geo-temperature geothermal energy in the surrounding rock can be extracted by tunnel lining ground heat exchangers (GHEs) and stored in phase change material (PCM) plates to realize the cold energy utilization. However, the research of the coupling heat transfer of tunnel lining GHEs and PCM plates has been rarely reported. In this study, a 3D coupling heat transfer model of tunnel lining GHEs and PCM plates was developed to investigate the cold energy storage performances of PCM plates under different PCM and tunnel parameters. The circulative iteration calculation is used to solve the coupling model. The results show that the cold energy storage of PCM plates utilizing tunnel lining GHEs for energy storage is feasible. The PCM melt fraction and solid phase PCM proportion within the PCM plates decrease and increase respectively with an increase in the PCM thermal conductivity and melting temperature and a reduction in the surrounding rock temperature. The cold energy storage efficiencies of PCM plates improve by 77.8% and 34.1% as the PCM thermal conductivity and melting temperature increase by 1 W/(m K) and 4 ℃. Moreover, the cold energy storage efficiency of PCM plate enhances by 68.5% as the surrounding rock temperature reduces from 10 to 1 ℃. A larger difference between the surrounding rock temperature and PCM melting temperature is efficient for the cold energy storage of PCM plates, and the cold energy storage time and temperature difference show a power function relationship. Finally, increasing the tunnel lining GHEs length is conducive to enhancing the cold energy storage efficiency of PCM plates, whereas this enhancement is limited. In actual applications, selecting a reasonable tunnel lining GHEs length is necessary.

A highly accurate model for prediction of thermal conductivity of carbon-based nano-enhanced PCMs using an artificial neural network

Nano-PCMs, which contain nanostructured materials, can enhance the low thermal conductivity of phase change materials (PCMs). It is crucial to predict the precise thermal conductivity of nano-PCM to assess the heat transfer during phase change procedures such as melting and solidification. In this study, artificial neural network (ANN) and response surface method (RSM) were used to develop a model for predicting the thermal conductivity of carbon-based nano-enhanced phase change materials (NEPCMs) using 482 experimental samples collected from various datasets. The carbon-based nano-particles were SWCNTs, MWCNTs, graphite, graphene, and (CNFs). Six input parameters were considered with varying temperature, mass fractions, sizes, thermal conductivities of PCMs and nano-particles, and the phase of PCM. The ANN was designed using a multi-layered feed-forward structure and Levenberg–Marquardt back-propagation algorithm with one hidden layer consisting of eight neurons. The transfer function was varied to achieve optimal performance. It was revealed that the predictive capacity of the ANN model is greater than that of the RSM model based on their corresponding the coefficient of determination (R2) and root mean square error (RMSE) values. The developed ANN achieved a R2 value of 0.99, while the RSM method model achieved an R2 value of 0.79.

Protic dialkylammonium-based ionic liquids as promising solid-solid phase change materials for thermal energy storage: Synthesis and thermo-physical characterization

The widespread deployment of renewable energies such as solar and wind implies the parallel development of energy storage systems to deal with their intermittency. Storing renewable energy as thermal energy is one of the alternatives under constant research. In this regard, phase change materials (PCMs) are able to store large amounts of energy at a nearly constant temperature in the form of latent heat. Nevertheless, most of these PCMs undergo solid-liquid transitions, which hamper their implementation due to leaking issues, forcing the need for containment and increasing the final cost of the TES system.Therefore, a class of PCMs possessing solid-solid transitions has emerged to avoid these problems, the so-called organic ionic plastic crystals (OIPCs). Currently, the scientific literature and the number of OIPCs available for TES are rather scarce. Herein, we present the synthesis, the structural, and the thermo-physical characterization of nine OIPCs based on the dioctylammonium cation combined with different organic and inorganic acids as the anions. Particular attention has been paid to the most characteristic thermal properties of PCMs (latent heat, transition temperature, subcooling, thermal conductivity, and energy storage density), evaluating their thermal stability and the reliability of the most promising materials over thermal cycling as well. Among the prepared OIPCs, 3 of them, [DOA][NO3], [DOA][Cl], and [DOA][FOR], exhibited promising properties with remarkable solid-solid transition enthalpies of 156.6 J/g (at 41.4 °C), 101.2 J/g (at 20.0 °C) and 58.4 J/g (at 29.7 °C), respectively. These 3 OIPCs showed high potential to be used and integrated as PCMs in TES systems at temperatures below 45 °C.

Design and thermal performance evaluation of a new solar air collector with comprehensive consideration of five factors of phase-change materials and copper foam combination

The low thermal conductivity of phase-change materials (PCMs) reduces the heat storage capacity, heat release efficiency, heat peak migration capacity, and heat collection efficiency of PCM-based solar air collectors (SACs) in building heating systems, thereby affecting the comprehensive heating requirements of building users. To solve this problem, in this study, a new SAC was designed with PCMs and copper foam (Type 2: PCMACFC-SAC model) by comprehensively considering five factors, namely thermal conductivity, heat storage capacity, heat release efficiency, heat peak migration capacity, and heat collection efficiency, based on a pure PCM-based SAC (Type 1: PCM-SAC model). Thereafter, the two models were compared. Comparative results of the thermal-performance evaluation index revealed that the thermal conductivity of the Type 2 test block was 2.2–2.3 times that of the Type 1 test block, indicating significantly improved thermal conductivity of the copper foam and PCM composite test block. Although the PCMACFC-SAC displayed better heat storage speed rate, time, and quantity, its nighttime heat release time was approximately 19.64% less than that of the PCMs-SAC; PCMACFC-SAC had a lower output temperature and smaller temperature fluctuation range over the solar day, which can increase indoor thermal comfort. The daily average heat collection efficiency of the PCMACFC-SAC decreased by 12.77%, indicating a stronger heat peak migration ability, which can transfer a greater amount of heat energy to be released at night.

Study on the temperature control performance of photovoltaic module by a novel phase change material/heat pipe coupled thermal management system

High photovoltaic (PV) module temperature leads to the degradation of electrical efficiency, and passive PV thermal management systems, such as phase change materials (PCMs) and heat pipes (HPs), have been widely adopted to address this challenge. Due to the low thermal conductivity of PCM and the limited heat exchange capacity in the HP condensation section, this paper proposes a novel configuration for a PV thermal management system utilizing a phase change material/heat pipe coupled module (PV-PCM/HP). The experimental results showed that the performance of the coupled PCM/HP system was superior to that of the single system. A numerical model was developed to simulate and analyze the temperature variation and coupled heat transfer characteristics of the PV-PCM/HP system. The main components of heat transfer gradually change from PCM (PCM-dominated) to HP (HP-dominated), and PCM even plays a negative role during the solidification stage, which means that the coupled thermal management depends on HP only. Four design parameters (the number of HPs, PCM thermal conductivity, PCM phase change temperature, and PCM thickness) of the PV-PCM/HP system are discussed to investigate the effects on the performance of the PV-PCM/HP thermal management system. This shows that the increase in the number of heat pipes and PCM thickness can effectively improve the performance, but they should be determined according to technical and economic analysis. When the PCM thermal conductivity is >2.7 W/(m·K), it has little effect on thermal management performance under the conditions described in this paper. The value of the PCM phase change temperature should be determined according to actual weather conditions, and the purpose is to make the PCM melting period coincide with the period of higher solar radiation and lower phase change temperatures.

A battery thermal management scheme suited for cold regions based on PCM and aerogel: Demonstration of performance and availability

The temperature of lithium-ion batteries affects their safety, operation efficiency and life. In a cold environment, the battery system may have the problem of low temperature. To solve this problem, this work has established a battery thermal management system (BTMS) for public transport batteries, which uses phase change material (PCM) and aerogels. PCM can store the heat generated by the battery through latent heat, and aerogel can maintain the temperature of the battery system through excellent thermal insulation and avoid the impact of low ambient temperature. First, according to the thermal conductivity characteristics of lithium-ion batteries, the optimal PCM distribution for a single battery is determined. The BTMS is designed according to the optimal distribution. Second, the effects of PCM thermal conductivity and aerogel thickness on the temperature variation of the BTMS under design conditions are investigated. Finally, the external environment parameters of Beijing in January are introduced to evaluate the availability of BTMS. The results show that PCM is optimal at 5.3 mm in the cell thickness direction. Increasing PCM thermal conductivity can reduce the demand for the thickness of the aerogel layer and the maximum temperature of the battery. During the whole operation of the BTMS in Beijing in January, the battery temperature can be maintained in the range of 20∼28 °C, and the maximum temperature difference is less than 2.6 °C. This work provides valuable information for designing the BTMS of batteries used for public transport in cold environments.

Performance optimization of metal hydride hydrogen storage reactors based on PCM thermal management

Metal hydrides (MH) are considered promising hydrogen storage materials. In applications, the heat transfer characteristics of MH hydrogen storage reactors are closely related to their storage performance. Phase change materials (PCM) were proven to integrate with MH reactors for effective thermal management. Nevertheless, the PCM based MH reactors (MH-PCM reactors) still need to overcome the heat transfer resistance and the loss of volumetric hydrogen storage capacity caused by the PCM volume proportion. The present work established a mathematical model to describe the transfer and reaction process in the MH-PCM reactor. Various parameters were discussed in the current work. It was found that the increased PCM's amount and latent heat have a restricted effect on the enhancement of heat transfer and absorption reaction rate. The higher PCM's thermal conductivity and hydrogen supply pressure effectively enhanced the heat transfer and reaction rate. Furthermore, the increased absorption pressure can improve PCM's sensible heat storage capacity, which provides a new approach for optimizing PCM consumption. Finally, the quantitative relationship among the volumetric hydrogen storage capacity, the volume fraction and thermophysical properties of PCM, and the absorption pressure were established by systematic analysis, which provides an essential theoretical basis for the optimization of MH-PCM reactors.

High thermal inertia mortars: New method to incorporate phase change materials (PCMs) while enhancing strength and thermal design models

This study proposes and tests a new method to incorporate Phase Change Materials (PCMs) into construction materials to increase building envelopes' thermal inertia without causing a decrease in the material's compressive strength. Mortars with three water-to-cement ratios (0.45, 0.55, 0.65) and, therefore, different porosity were used in this study as base materials. Following our novel procedure, PCM was incorporated into the pore structure of hardened samples through immersion into heated PCM in a liquid state and vacuum application for three different vacuum periods (15 min, 1 h, and 4 h). Final porosity, absorbed PCM volume, thermal conductivity, thermal effusivity, and compressive strength were determined. An increase in all studied properties was observed. The maximum enhancement was observed in samples with 0.65 w/c and 4 h of vacuum, which corresponded with the samples with the highest PCM incorporated (7.01 % of PCM by sample volume). This maximum increase was 17.86 % in thermal conductivity, 24.68 % in thermal effusivity, and 22.59 % in compressive strength. Besides, estimation models for the thermal properties and compressive strength were developed, showing high accuracy (errors lower than 10 %). These estimation models were combined to create a target-by-design system that determines the initial porosity and PCM content required to obtain a desired combination of compressive strength and thermal conductivity or effusivity. The thermal conductivity and effusivity of the solid part of the mortar (excluding the air) were obtained based on these models. These values can be very useful as an input for simulating the thermal behavior of cementitious composites using computational models.

Effects of thermophysical properties on optimal selection of phase change material for a triple tube heat exchanger unit at different time scales

The multi-criteria decision making (MCDM) method has been widely applied to select phase change material (PCM) for various applications. However, the relationship between the thermophysical properties of a PCM and the optimization objective, as well as the effect on different time scales for specific applications, has not been addressed in the selection process of the optimum PCM. In this study, to solve the above two issues, first, an orthogonal experiment with five factors and four levels is designed to explore the effect of the thermophysical properties of PCMs on the heat storage ratio of a triple tube heat exchanger (TTHX) unit based on a numerical simulation. Then, the criteria weights are determined based on the range analysis at different time scales, and finally, the technique for order performance by similarity to an ideal solution (TOPSIS) method is employed to perform the ranking and selection. The results indicated that the thermophysical properties have a significant influence on the heat storage rate. When the melting time was 20 min, the PCM density and thermal conductivity had higher weights and PlusICE-S117 was selected as the optimal PCM. However, when the melting time was 150 or 250 min, the PCM density and melting enthalpy were the primary criteria to consider, and the best choice was Urea-NaCl. Furthermore, the reliability and effectiveness of the proposed PCM selection method were verified through a comparison with the TOPSIS-entropy method.

Prediction of thermal transport properties for Na2CO3/Graphene based phase change material with sandwich structure for thermal energy storage

In this paper, a new Na2CO3/Graphene based phase change material (PCM) with sandwich structure was proposed and designed for the application of thermal energy storage, the microstructure of which was established, and its thermal transport properties were investigated by means of molecular dynamics simulations, and the prediction method for transport properties with desired accuracy was also developed and determined. The results indicate that the construction of sandwich structure leads to the limiting effect of ions contained in the PCM simulation system, and the self-diffusion coefficient was reduced and shear viscosity was increased. Besides, the construction of sandwich structure was benefit to the thermal conductivity enhancement, the thermal conductivity of PCM can be increased by 32.51% on average in the studied temperature range, and the maximum enhancement can reach to 51.37%, which provides an attractive possible strategy for thermal conductivity improvement for molten salt based PCM, which is expected applied in the concentrated solar power generation system.

Performance evaluation of a novel concentric metal hydride reactor assisted with phase change material

Hydrogen storage is a promising technique that could handle the challenges of intermittent renewable production on the electric grid. Metal Hydride (MH) is a promising hydrogen storage technique owing to its safety, availability, and high volumetric storage density. However, MH requires an efficient heat management system. Therefore, this paper proposes a multi-layer cylindrical reactor where layers of MH and phase change material (PCM) are alternatively arranged. A numerical model is developed utilizing COMSOL Multiphysics software and is validated to predict the performance of the proposed reactor at various design parameters. As PCM thermal conductivity changes from 0.2 to 3 W/m.K, absorption time, based on 90 % absorption, reduces from 3555 s to 675 s (∼5.33 times reduction). Compared to a reference case, four layers system reduces absorption time by 78 %. Lithium nitrate trihydrate as PCM material exhibits the best performance, allowing four layers to greatly reduce reactor volume with a slight absorption time delay. The analysis introduces two novel parameters expressing the absorption rate per system mass and volume. From the intensive analysis, the specific capacity rate (SCR) of the proposed reactor is 1.51 gH2/min/kgsys, while the volumetric capacity rate (VCR) of the proposed reactor is 3016 gH2/min/m3sys. SCR and VCR are 3.4 and 3.12 times higher than the corresponding values in literature.

Phase Change Materials Energy Storage Enhancement Schemes and Implementing the Lattice Boltzmann Method for Simulations: A Review

Utilizing phase change materials (PCMs) is one of the most effective methods of storing thermal energy and is gaining popularity in renewable energy systems. In order to analyze PCM performance, various numerical methods have been deployed to study the transient behaviour during phase changes. PCMs’ low thermal conductivity prevents their use as pure PCMs in industrial applications. There are various efficient methods of enhancing PCM thermal conductivity, which are addressed in this article. On the other hand, the lattice Boltzmann method (LBM) is very inclusive in the numerical simulation of complex fluid flows, thermal transport, and chemical interactions because of its ability to simply represent various complex physical phenomena, suitability for parallel programming, and easy coding and implementation. Many numerical studies have been conducted on PCMs using the LBM. This study aims to review these studies and categorize them in a way so that one may thoroughly understand the LBM’s capabilities in the simulation of PCM-related investigations. First, PCM characteristics and applications are presented, then the LBM implementation in PCM problems is addressed. Afterward, the fabrication and types of PCMs are mentioned. Next, the improvement of thermal energy storage methods of PCMs is stated. Furthermore, governing equations are reviewed. Lastly, the opportunities and challenges of the LBM in PCMs are discussed.

High-Performance Heat Storage Phase Change Composite by Highly Aligned N-Doped Mesoporous Carbon for Efficient Battery Thermal Management

Limited by leakage from inherent liquid to solid phase transition and inferior heat transfer, pristine organic phase change materials (PCMs) possess extremely low thermal storage performance. Thus, establishing shape-stable PCM composites with enhanced thermal conductivity and latent heat is a key task for practical application. Herein, we constructed N-doped mesoporous carbon monoliths with a highly aligned structure by directional freeze-drying to encapsulate polyethylene glycol. Benefiting from the mesoporous carbon matrix and pyridinic N from N-doping, the PCM composite possessed large latent heat (140 J·g–1) and leakage proof at 80 °C. Meanwhile, the highly aligned structure created a fast heat transfer pathway that improved thermal conductivity of the PCM composite by 1500%. Being different from most research studies, highly aligned carbon was utilized as the support directly without skeletons, which could increase PCM loading capacity and thermal conductivity as well. The PCM composite can be employed as promising candidates for thermal management working efficiently to decrease battery pack temperature by 13 °C and improve discharge capacity by 28%.

Experimental investigation on the effect of phase change materials for thermal management improvement of the fast charging power module

This experimental research clarifies the advantageous effect of adding paraffin wax as the appropriate organic phase change material (PCM) to control the temperature rise of the fast charging power module (100 mm × 50 mm × 20 mm). The effects of PCM physical parameters (thermal conductivity, melting point temperature and filling thickness) on the thermal management performance of changing module are examined, and the PCM melting process is visualized to reveal the mechanism of PCM in improving the thermal management performance. Results show that the temperature is decreased by 46.4 °C with coupling the PCM, and a temperature reduction of 11.8 °C is found with increasing the air flow velocity. Increasing the PCM thermal conductivity from 0.2 W/(m∙K) to 5 W/(m∙K) in 1800 s can decrease the extreme temperature from 60.1 °C to 51.9 °C. The filling PCM thickness of 4.5 mm is more successful than other thicknesses in the thermal management performance. These research results will provide reliable technical solutions for improving the thermal management performance of charging piles and solving the effective thermal management of high-power quick charging piles.

A Numerical Study of the Suitability of Phase-Change Materials for Battery Thermal Management in Flight Applications

Battery pack specific energy, which can be enhanced by minimising the mass of the battery thermal management system (BTMS), is a limit on electric fixed-wing flight applications. In this paper, the use of phase-change materials (PCMs) for BTMSs is numerically explored in the 3D domain, including an equivalent circuit battery model. A parametric study of PCM properties for effective thermal management is conducted for a typical one-hour flight. PCMs maintain an ideal operating temperature (288.15 K–308.15 K) throughout the entire battery pack. The PCM absorbs heat generated during takeoff, which is subsequently used to maintain cell temperature during the cruise phase of flight. In the control case (no BTMS), battery pack temperatures fall below the ideal operating range. We conduct a parametric study highlighting the insignificance of PCM thermal conductivity on BTMS performance, with negligible enhancement observed across the tested window (0.1–10 W m−1 K−1). However, the PCM’s latent heat of fusion is critical. Developers of PCMs for battery-powered flight must focus on enhanced latent heat of fusion, regardless of the adverse effect on thermal conductivity. In long-haul flight, an elongated cruise phase and higher altitude exasperate this problem. The unique characteristics of PCM offer a passive low-mass solution that merits further investigation for flight applications.