Application Of Phase Change Materials Research Articles

An Overview of Phase Change Materials and Their Applications in Pavement

The composite of a phase change material (PCM) and bitumen or asphalt as a matrix is expected as a new, advanced material for road construction. The main motivation for this article was to show the new possibilities and perspectives of developing the pavement with the usage of PCMs. Incorporating PCMs into paving materials can improve their properties, including allowing the regulation of the pavement temperature, enhancement of the pavement durability, and avoiding the phenomenon of a heat-island on the road. The main purpose of this article was to evaluate contemporary investigations in the area of the application of PCMs in pavement materials, especially asphalt and bitumen; to summarize the advantages and disadvantages of the implementation of PCM for road construction; and to discuss further trends in this area. This manuscript explored the state of the art in this area based on research in the literature. It shows the possible material solutions, presenting their composition and discussing their key properties and the manufacturing technologies used. The possibilities for further implementations are considered, especially economic issues.

Thermal performance enhancement with snowflake fins and liquid cooling in PCM-based battery thermal management system at high ambient temperature and high discharge rate

The application of phase change materials (PCMs) in battery thermal management system (BTMS) is restricted by their low thermal conductivity and the challenge of heat-storage saturation after latent heat depletion, particularly in conditions with high ambient temperature and discharge rate. To enhance the performance of thermal management, this study firstly evaluates the thermal behaviors of two designs, Batteries-PCM and Batteries-PCM-Fins, under discharge rates of 3C and 5C, in conjunction with ambient temperatures of 25 °C and 40 °C. Building on this foundation, a hybrid thermal management system that incorporates snowflake fins and liquid cooling is proposed. The cooling efficiency of five different liquid cooling plate configurations (Design I-V) is compared, and the impact of coolant flow rate is explored. The results indicate that the snowflake fins in the Batteries-PCM-Fins design effectively reduce battery temperatures at a 3C discharge rate, maintaining a max temperature difference below 3 °C. However, at a 5C discharge rate and 40 °C ambient temperature, there is a noticeable increase in the peak temperature of the battery module across numerous cycles. Among the tested designs, Design IV shows the best performance. Specifically, when the coolant flow rate is 0.1 m/s, the discharge rate is 5C, and the ambient temperatures are 25 °C and 40 °C, compared to the design lacking a liquid cooling plate, the maximum temperature of the battery module decreases by 17.40 % and 21.36 % respectively, with respective decreases of 42.53 % and 55.77 % in the maximum temperature difference.

Experimental analysis of building envelope integrating phase change material and cool paint under a real environment in autumn

The application of phase change material (PCM) and cool paint (CP) to building envelope is one of the effective solutions to improve thermal comfort of passive buildings. Therefore, the thermal performance of buildings in Hefei, China in autumn is compared and analyzed by integrating PCM and CP into the building envelope. According to the comprehensive analysis of indoor thermal environment and the ability to maintain indoor thermal comfort, it is concluded that the combined application of PCM and CP is better than the application of PCM or CP alone. And the combination of PCM and CP laid on the south wall and roof respectively is the best. It is more suitable for commercial buildings, which can prolong indoor air temperature (Ti) in the thermal comfort zone for more than 10 hours during the day. The combination of PCM and CP laid on the roof can prolong Ti in the thermal comfort zone for more than 8.05 hours, which is more suitable for residential buildings. The purpose is to explore the best combination mode of residential and commercial buildings according to the characteristics of temperature change and building types (according to people's main use time) in the real environment.

Analysis of melting behavior of layered different phase change materials for a cylinder insert into a channel

Phase change materials (PCMs) have diverse fields of application due to higher thermal inertia. The present study explores the melting behavior in dual-layered different PCMs in a cylindrical lithium-ion battery module placed in a long channel under the hot air stream. The main cylinder is packed with paraffin wax and covered PCM is chosen as calcium chloridehexahydrate (CaCl2-6H2O). The material between two PCMs is considered highly conductive and impermeable. The involved mathematical equations in two-dimensional forms are numerically simulated the applying the finite volume technique. The primary important parameters of melting behavior are the difference in temperature and inlet air velocity. The analysis is carried out for the effective parameters such as the inlet air temperature (Thot = 100 °C and 120 °C) and air velocity (սair = 2.5 and 5.0 m/s). The results revealed that an increase in air velocity reduces the highest and average temperature of the PCM. The changes in melting time of PCMs decline with time. Higher inlet air temperature also causes fast melting of the PCMs over time. The analysis revealed that the application of PCMs is undue when there is no phase change process. The analysis also revealed that an increment in the inlet air velocity causes a decrease in the average temperature. For the same air inlet temperature (Thot) higher air velocity leads to a slower rate of the melting process Therefore, melting time is less by ∼ 30 % (for the inner layer) and 32 % (for the outer layer) with decreasing air velocity. The findings of this study will help the designer to improve the battery thermal management system by modulating the temperature.

Shape-stable phase change materials based on carboxymethyl chitosan/boron nitride nanosheets high-strength aerogel

The application of phase change materials (PCMs) in energy storage and temperature control systems holds significant promise for enhancing energy efficiency and environmental sustainability. Herein, the development of a boron nitride nano-aerogel-supported PCM, reinforced by carboxymethyl chitosan (CMCS) and oxidized corn starch (DCS) cross-linking was reported. This approach involved the utilization of polydopamine-modified boron nitride nanosheets (PDA@BNNS) for the fabrication of a thermally conductive skeleton, while carboxymethyl chitosan (CMCS) and oxidized corn starch (DCS) were utilized as reinforcing material and cross-linking agent, respectively. The skeleton was prepared via a sol-gel method and freeze-drying technique, while polyethylene glycol (PEG) was subsequently encapsulated using a vacuum impregnation method. Notably, the prepared skeleton exhibits a compressive stress of 12.18 MPa at 80 % strain, much higher than other boron nitride nanosheets aerogels reported in literature. The cross-linked boron nitride skeleton enhances the thermal conductivity of the composites by 137.4 % compared to pure PEG. Furthermore, due to the highly porous structure of the skeleton, the PEG mass fraction reaches 96.0 wt%, resulting in a phase change enthalpy of 181.5 J/g. The results suggest that this composite material is a promising PCM candidate for thermal energy storage applications.

Phase Engineered Composite Phase Change Materials for Thermal Energy Manipulation.

Phase change materials (PCMs) present a dual thermal management functionality through intrinsic thermal energy storage (TES) capabilities while maintaining a constant temperature. However, the practical application of PCMs encounters challenges, primarily stemming from their low thermal conductivity and shape-stability issues. Despite significant progress in the development of solid-solid PCMs, which offer superior shape-stability compared to their solid-liquid counterparts, they compromise TES capacity. Herein, a universal phase engineering strategy is introduced to address these challenges. The approach involves compositing solid-liquid PCM with a particulate-based conductive matrix followed by surface reaction to form a solid-solid PCM shell, resulting in a core-shell composite with enhanced thermal conductivity, high thermal storage capacity, and optimal shape-stability. The core-shell structure designed in this manner not only encapsulates the energy-rich solid-liquid PCM core but also significantly enhances TES capacity by up to 52% compared to solid-solid PCM counterparts. The phase-engineered high-performance PCMs exhibit excellent thermal management capabilities by reducing battery cell temperature by 15°C and demonstrating durable solar-thermal-electric power generation under cloudy or no sunshine conditions. This proposed strategy holds promise for extending to other functional PCMs, offering a compelling avenue for the development of high-performance PCMs for thermal energy applications.

Preparation and characterization of double-shell phase change material microcapsules with flame retardancy and temperature regulation capability as low-emission building fillers

The building application of phase change materials (PCMs) has attracted widespread attention due to energy conservation and emission reduction. In this study, designed and prepared by two-step polymerization poly melamine tetramethylene phosphonium sulfate (PMTMPS) coating the raw phase change materials microcapsules (MPCMs), which were novel double-shell microcapsules (D-MPCMs). D-MPCMs further achieved low smoke and low toxicity in the fire based on enhancing the temperature regulation performance of MPCMs. The chemical structure of D-MPCMs was characterized by Fourier transform infrared (FTIR) spectroscopy, and 13C solid-state nuclear magnetic resonance (NMR). Transmission electron microscope (TEM) confirmed that D-MPCMs were successfully prepared, whose shapes were regular spherical. The results of differential scanning calorimetry (DSC) showed that D-MPCMs revealed excellent phase transition enthalpy (80.51 J/g). Then, the resultant D-MPCMs had good thermal reliability and stability from the thermogravimetric analysis (TGA), characterized by a residual mass of D-MPCMs was 17 % more than that of MPCMs. In the cone calorimeter test (CCT), we confirmed that the coated PMTMPS significantly reduced the fire risk parameters of the rigid polyurethane foam (RPUF) containing D-MPCMs (D-MPCM/RPUF) referring to the heat release rate (HRR), total heat release (THR), and total smoke production (TSP). D-MPCM/RPUF exhibited the lowest peak values of HRR and TSP, which were 400.115 kW/m2 and 10.512 m2, respectively. In addition, the PMTMPS shell significantly enhanced the solar photo-thermal conversion performance of the D-MPCMs. To sum up, D-MPCMs have great potential to improve flame retardancy, environmental protection, and temperature regulation capability for building thermal insulation materials.

Preparation and Thermal Performances of Lauric Acid/Polyvinyl Butyral/Graphene Nanoplates Composite Phase Change Materials

In recent years, there has been significant progress in the development and application of phase change materials (PCMs) for thermal energy storage. The new lauric acid (LA)/polyvinyl butyral (PVB)/graphene nanoplates (GNP) composite phase change materials (CPCM) are prepared using the solution blending method, in which LA acts as PCM, PVB serves as support material, and GNP is used as thermally conductive enhancer. The prepared CPCM with 80 wt% LA can retain stable shape without leakage. The Fourier‐transform infrared and X‐ray diffractometer results indicate that there is no chemical reaction among the various components of the CPCM. The differential scanning calorimeter results show the CPCM3 (with 80 wt% LA and 5 wt% GNP) has melting latent heat of 134.41 KJ Kg−1 with melting temperature of 41.73 °C. The thermal conductivity tests present that thermal conductivity of CPCM3 is 0.689 W (m K)−1, which is 3.83 times that of the PCM2. The thermogravimetric analyzer results verify that the CPCM possess good thermal stability within the operating temperature range of 35–45 °C without any degradation. The thermal cycling tests indicate that CPCM have good thermal reliability. Therefore, it has promising applications in building energy conservation, solar thermal systems, thermal management, and textiles.

Optimization of a Ge2Sb2Te5-Based Electrically Tunable Phase-Change Thermal Emitter for Dynamic Thermal Camouflage.

Controlling infrared thermal radiations can significantly improve the environmental adaptability of targets and has attracted increasing attention in the field of thermal camouflage. Thermal emitters based on Ge2Sb2Te5 (GST) can flexibly change their radiation energy by controlling the reversible phase transition of GST, which possesses fast switching speed and low power consumption. However, the feasibility of the dynamic regulation of GST emitters lacks experimental and simulation verification. In this paper, we propose an electrically tunable thermal emitter consisting of a metal-insulator-metal plasmonic metasurface based on GST. Both optical and thermal simulations are conducted to optimize the structural parameters of the GST emitter. The results indicate that this emitter possesses large emissivity tunability, wide incident angle, polarization insensitivity, phase-transition feasibility, and dynamic thermal camouflage capability. Therefore, this work proposes a reliable optimization method to design viable GST-based thermal emitters. Moreover, it provides theoretical support for the practical application of phase-change materials in dynamic infrared thermal camouflage technology.

Engineering tiramisu-like phase change nanocomposite for superior thermal energy management and electromagnetic interference shielding

Exploiting advanced nanocomposites isochronally integrating outstanding thermal conductivity (TC) and electromagnetic interference shielding effectiveness (EMI SE) can boost the cutting-edge application of phase change materials. Here, we report a tiramisu-like composite (GMP), where the typical “crust-and-cheese” hierarchical structure is replicated by an innovative two-step bidirectional freezing assembly (BFA) and compressive densification. Hierarchical-aligned graphene array (G-GA) with ultralow thermal resistance is fabricated through 1st BFA and graphitization. During the 2nd BFA, the MXene-CNF crosslinking network with hydrogen-bond actions is used for encapsulating polyethylene glycol (PEG) onto the microlayers of the G-GA skeleton. Remarkably, the microlaminated GMP4 achieves a recorded TC of 34.05 W m–1 K–1, unprecedented EMI SE of 87.4 dB, and preferable enthalpy density of 179.4 J cm–3, along with leakage-free function, and eminent thermal durability. Furthermore, the GMP-loaded equipment is demonstrated for efficient microelectronics cooling and sustainable solar energy utilization. This work opens new avenues for multiscale designing multifunctional macro-composites, broadening the application prospects in advanced electronics and solar energy utilization systems.

Highly efficient solar-thermal-electric conversion based on asymmetric binary-architecture design in solid-solid composite phase change materials

The application of phase change materials (PCMs) in solar-thermal conversion is largely limited by the inherently inferior thermal conductivity (TC) and poor solar-thermal energy transition capacity of PCMs. Herein, 1,1,1-tri(hydroxymethyl)ethane@melamine foam/cellulose nanofiber/graphene nanoplate (TME@MCGx) shape-stable composite PCMs (ss-CPCMs) are prepared by encapsulating TME into MCGx aerogels. Profited by the effective heat-conducting MCG25 networks, the resulting TME@MCG25 ss-CPCM achieves high TC of 0.73 Wm-1k−1 for internal heat conduction. Meanwhile, the combination of surface photothermal etching and hydrophobic polydimethylsiloxane (PDMS) coating endows the obtained T-TME@MCG25 highly efficient solar-thermal conversation efficiency of 93.1 %, arising from the exposed 3D MCG25 skeletons for absorbing sunlight and the thin PDMS layer for preventing the absorbed solar-thermal energy from radiating and dissipating. Consequently, the solar-thermal-electric (STE) conversion system equipped with T-TME@MCG25 generates the prominent output voltage of 213.0 mV and current of 37.6 mA. Furthermore, the acquired T-TME@MCG25 exhibits remarkable hydrophobicity and self-cleaning performances, due to the micro-nano structures of MCGx skeleton surfaces and the low surface energy of PDMS coating. The design strategy of asymmetric binary-architecture containing 3D photothermal absorption layer and water repellency layer provides a valuable insight into STE energy conversion associated with hydrophobic ss-CPCMs, which can alleviate the looming energy crisis.

Composite phase change materials with room-temperature-flexibility

Phase change materials (PCMs) have attracted considerable attention for effectively addressing the problem of thermal energy supply–demand mismatch. However, the practical application of PCMs is still hindered by inherent challenges such as crystalline rigidity, leakage susceptibility, and poor thermal conductivity. In this research, on the basic of thermal control provided by phase change storage and the elastic behavior supported by thermoplastic polyester elastomer at room temperature, we fabricated a new type of composite PCM (CPCM) that exhibits flexibility even at room temperature. This CPCM demonstrates good shape and thermal stability. Furthermore, the carbon nanotubes-COOH modified with lauric acid (LA) can be uniformly dispersed within the CPCM matrix, thereby enhancing the thermal conductivity of the CPCM. Additionally, the composite material exhibits a promising thermal management performance for high-temperature lithium-ion (Li-ion) batteries. These findings open up new possibilities for the development of room- temperature flexible CPCMs.

Study on the Influence of the Application of Phase Change Material on Residential Energy Consumption in Cold Regions of China

As the impact of climate change intensifies, meeting the energy demand of buildings in China’s cold regions is becoming increasingly challenging, particularly in terms of cooling energy consumption. The effectiveness of integrating phase change material (PCM) into building envelopes for energy saving in China’s cold regions is unclear. The aim of this study is to assess the effectiveness of PCM integration in building enclosures for energy efficiency in these regions. The research monitored and recorded indoor temperature data from typical residential cases from May to September. This measured data was then used to validate the accuracy of EnergyPlus22-1 software simulation models. Subsequently, the calibrated model was utilized to conduct a comparative analysis on the effects of PCM on indoor temperatures and cooling energy consumption across these regions. The results of these comparative analyses indicated that PCM can alleviate indoor overheating to varying degrees in severe cold regions of China. Focusing on north-facing bedrooms, applying PCMs reduced the duration of overheating in non-air-conditioned buildings in severe cold regions of China by 136 h (Yichun), 340 h (Harbin), 356 h (Shenyang), and 153 h (Dalian). In terms of cooling energy consumption, the energy saved by applying PCMs ranged from 1.48 to 13.83 kWh/m2. These results emphasize that the performance of PCM varies with climate change, with the most significant energy-saving effects observed in severe cold regions. In north-facing bedrooms in Harbin, the energy-saving rate was as high as 60.30%. Based on these results, the study offers guidance and recommendations for feasible passive energy-saving strategies for buildings in severe cold and cold regions of China in the face of climate change. Additionally, it provides practical guidance for applying PCMs in different climatic zones in China.

The surface and interlayer modification of montmorillonite and its potential application for thermal energy storage

Phase change materials (PCMs) could take full advantage of clean and renewable energy, because of their ability to convert and store various energy. However, due to the leakage and low heat storage capacity, the large-scale commercial application of PCMs is seriously limited. In this work, natural montmorillonite (MMT) was modified by organic amine coupling agent that was assembled into the interlayer of MMT. The energy storage performance and the stability of composite PCMs were significantly improved by using a novel frame of MMT encapsulated Paraffin (PA). The MMT-KH550-HAc/PA composite PCMs prepared by organic intercalation provides suitable pore structure and hydrophilicity to encapsulate more PA, resulting in the highest latent heat capacity (150 J/g) that is significantly increased by 144.1% from 60 J/g. Meanwhile, the energy storage stability of MMT-KH550-HAc/PA is also improved, and the latent heat of phase change is reduced by 3.2% after 100 cycles. The present MMT-KH550-HAc/PA has remarkable latent heat capacity and energy storage stability, which can be potentially applied to the solar water heaters.

Synthesis and properties of biomass derived carbon/PEG composite as photothermal conversion effective phase change material for functional concrete

Mixing phase change material (PCM) into concrete is a practical strategy for functionalizing concrete as an energy-storage unit. This study aims to invent an efficient photo-thermal conversion type PCM for the manufacturing energy storage functional concrete, which meet the needs of hydration heat storage and thermal storage in service. To solve the liquid leakage problem of PCM, a novel bamboo-based hydrothermal carbon sphere (HCS) with unique mesoporous structure was prepared to pack polyethylene glycol (PEG) to make shape stable PCM. The photo-thermal material nano-Ag was successfully introduced into the composite PCM through a high-voltage electrostatic field. To understand the stability and performance of the PCM for concrete use, the structural composition and thermal storage efficiency of Ag@HCS-CNTs/PEG in simulated concrete pore solution (a highly alkaline solution containing potassium, sodium, and calcium cations) were systematically studied via multiple characterization methods. After being soaked in concrete pore solution for 7 days, the PCM shows outstanding thermal storage density (147 J/g), photo-thermal conversion efficiency (110.6%), and resistance to Na+, Mg2+, Cl− and SO42−. In addition, the biomass subtracted PCM preparation has low energy consumption and low carbon emission features. These open a window of realistic PCM application in the structural concrete, insulation porous walls and energy storage buildings.

Thermal performance analysis of hollow bricks integrated phase change materials for various climate zones

AbstractThis comprehensive research addresses the significant challenge of building‐related energy consumption in Morocco. Our innovative approach involves integrating phase change materials (PCMs) into hollow bricks, strategically addressing the diverse climate zones prevalent in the country. The primary focus is on enhancing energy efficiency within structures. Leveraging detailed simulations and employing the enthalpy‐porosity approach, our study models the impact of PCMs on internal temperatures. Optimal outcomes are achieved by partially filling brick holes with PCMs in specific configurations, demonstrating the materials' ability to adapt to varying conditions. A noteworthy finding is the 2–3‐h phase shift observed in cold zones, indicating the potential for PCMs to effectively regulate temperatures. Equally significant is their capability to maintain a constant internal temperature of 26°C in hot zones, even amidst extreme external conditions reaching up to 47°C. This resilience underscores the novel and tailored thermal regulation potential of PCMs. Beyond the technical insights, our research highlights the paramount importance of considering regional climates in PCM applications' implementation. This awareness is crucial for optimizing energy performance in buildings and ensuring sustainability. In essence, this study contributes valuable knowledge and practical implications for the strategic deployment of PCMs to enhance building energy efficiency, emphasizing the need for context‐specific solutions in diverse environmental conditions.

Novel ablation resistant additive (Li2Mn4)O(CO3)4·H2O and its application in silicone rubber

This study shows the beneficial properties of using (Li2Mn4)O(CO3)4·H2O (P–LiMn2O4) as an anti-ablation additive in silicone rubber, effectively inhibiting ablation at all temperature ranges studied, indicating its potential as a valuable material. The experimental results show that P–LiMn2O4 enhances the anti-ablation process of silicone rubber through several mechanisms, including dehydration, decarbonization, gas production, and solid-solid phase change. These mechanisms induce heat absorption, gas film formation and ceramic phase formation. Furthermore, P–LiMn2O4 effectively improves the resistance of silicone rubber to ablation without compromising its mechanical properties. This study presents a method to enhance ablation resistance through multiple pathways, which can extend the application of phase change materials under extreme thermal conditions.

A Novel Sandwich-Structured Phase Change Composite with Efficient Photothermal Conversion and Electromagnetic Interference Shielding Interface.

Stability and multifunctionality greatly extend the applications of phase change materials (PCMs) for thermal storage and management. Herein, CuS and Fe3O4 nanoparticles were successfully loaded onto cotton-derived carbon to develop a multifunctional interface with efficient photothermal conversion and electromagnetic interference (EMI) shielding properties. 1,3:2,4-di-(3,4-dimethyl) benzylidene sorbitol (DMDBS) and expanded graphite (EG) formed an organic/inorganic three-dimensional network framework to encapsulate 1-octadecanol (OD) by self-assembly. Finally, multifunctional shape-stabilized PCMs (SSPCMs) with the sandwich structure were prepared by the hot-press process. Multifunctional SSPCMs with high load OD (91%) had favorable thermal storage density (200.6 J/g), thermal stability, and a relatively wider available temperature range with improved thermal conductivity to support the thermal storage and management realization. Furthermore, due to the synergistic enhancement of two nanoparticles and the construction of the carbon network with cotton carbon and EG, highly efficient photothermal conversion (94.4%) and EMI shielding (68.9 dB average, X-band) performance were achieved at about 3 mm thickness, which provided the possibility of the multifunctional integration of PCMs. Conclusively, this study provides new insights towards integrating solar energy utilization with the comprehensive protection of related electronics.

Medium-range structural order in amorphous Ge2Sb2Te5 phase change material

The crystallization rate is an important factor for the application of phase change materials as memory devices, which, thus, motivates a strong interest in the underlying crystallization processes. We analyzed the crystallization kinetics of as-deposited amorphous Ge2Sb2Te5 by differential scanning calorimetry, revealing that the thermal treatment below the crystallization onset temperature effectively enhances the crystallization rate compared to the as-deposited samples. Variable resolution fluctuation electron microscopy was carried out to characterize the corresponding amorphous structure of the as-deposited films and the differently annealed states regarding their medium-range order (MRO). As a result, relatively large MRO correlation lengths in the range of 3–4 nm were observed, whereas the MRO volume fraction doubled after longer annealing treatments, demonstrating the importance of MRO and MRO tuning for optimizing the properties of amorphous phase change materials. The increased volume fraction of the MRO seems to also favor an increased nanoindentation hardness.

Research on the performance failure of phase change materials thermal management for lithium battery

Lithium batteries are highly favored in the industry due to their high efficiency performance and long service life, but their thermal safety has always been a major challenge. The application of phase change materials (PCM) can effectively ensure the thermal safety. However, the inability to immediately dissipate heat from the PCM will result in their performance failure. The purpose of this study is to obtain the optimal parameter range considering the critical melting state of PCM through reverse analysis, to overcome the thermal issues during the discharge process of lithium batteries. The experiment and simulation of PCM thermal management are operated by considering input parameters, including liquidus temperature, discharge rate, thermal conductivity, filling thickness, and late heat. An explanation was provided for the entire melting process of PCM. The results showed that the simulation is reliable. The temperature of battery cooled by PCM is 15.4 K lower than that of battery not cooled for a discharge rate of 2C. The PCM with high liquidus temperatures is less likely to result in performance failure for conditions with high discharge rate. The cooling performance increases with the increase of discharge rate under the premise of effective thermal management. There is an optimal value for the filling thickness of PCM in terms of cooling performance and economic benefits. When the latent heat increased from 195 to 275 kJ/kg, the battery temperature decreased from 311.54 K to 311.02 K and the liquid fraction decreased from 83.16 % to 63.61 % at a discharging rate of 2C. This study provides an important insight for the application and further study of PCM in lithium batteries.