Field Of Thermal Energy Storage Research Articles

Thermal property optimization and shape stabilization of sugar alcohols phase change thermal energy storage materials reinforced by sintering synthesized alumina porous ceramics

Sugar alcohols phase change thermal energy storage materials have many advantages such as high latent heat, non-toxicity and abundance, which are extremely potential in the field of thermal energy storage. However, the application of sugar alcohols in thermal energy storage is greatly restricted by high supercooling. In this work, alumina porous ceramics (APC) were successfully prepared by replication template method, and then the prepared APC were modified by 3-aminopropyltriethoxysilane to obtain APC-SiX. The APC and APC-SiX were used to improve the thermal properties of erythritol (ET), d-mannitol (DMT) and d-dulcitol (DDT), respectively. Based on the results, the supercooling degree and solidification stability degree of sugar alcohols were suppressed observably, among which, the supercooling suppression for ET was the most significant. The supercooling degree and solidification stability degree of ET were suppressed to 3.3 ± 0.1 °C and 0.7 ± 0.2 °C, respectively. Besides, the thermal conductivity of the sugar alcohols was also obviously enhanced. Furthermore, the high latent heat, excellent cycling thermal stability and anti-leakage of sugar alcohols composite phase change materials (PCM) are also available. This conclusion is important for supercooling regulation and thermal property optimization of sugar alcohols, and indeed, can promote the utilization of sugar alcohols in thermal energy storage.

Simultaneous enhancement in thermal conductivity and heat storage capability of hexadecylamine/SiO2 for thermal energy storage

Hexadecylamine (HDA) was encapsulated into SiO2 nano-shell to enhance the heat transfer rate without deteriorating the heat storage capability by a simple, environmentally benign, and cost-effective method. The investigation on the thermal properties of HDA/SiO2 ss-CPCM demonstrated that a good trade-off between latent heat capability and thermal conductivity increment was achieved. The SiO2 shell promoted the thermal conductivity and hence increased the heat transfer rate. The heat transfer rate of HDA/SiO2 ss-CPCM was enhanced during both the heating and cooling processes. It took 554 s and 454 s for the composite to vary from 40 °C to 78 °C and from 78 °C to 40 °C, <659 s and 538 s for the pure HDA. Its thermal conductivity (0.2304 W m−1 K−1) is about 200 % of that of the pristine HDA when modified with 5.1 wt% SiO2. Besides, the composite achieved an exciting latent heat capacity with a crystallization enthalpy of 210.8 J g−1 and a melting enthalpy of 214.9 J g−1. The values were a good approximation to those of pristine HDA (227.6 J g−1 and 224.3 J g−1). It also illustrated excellent thermal stability and reliability after undergoing 100 heating/cooling cycles. HDA/SiO2 ss-CPCM with good thermal properties can be applied in the field of thermal energy storage.

Techno-economic assessment and optimization of the performance of solar power tower plant in Egypt's climate conditions

Egypt is a sunbelt nation with plenty of solar resources and significant wasteland areas, particularly in its southern and western regions. Concentrating solar power technologies are tried-and-true renewable energy systems that use solar radiation to produce electricity in nearby nations. These technologies have the potential to reduce costs in the future. Comprehensive techno-economic research has not been conducted to assess the potential for the solar power tower technique in Egypt; instead, solar photovoltaic and parabolic trough systems are given the majority of the attention. The major goal of this article is to persuade the Egyptian government to pursue solar power tower technology and meet the accompanying difficulties. Using system advisor model software, six distinct locations were used to simulate a 100 MW plant for solar power tower technology. Based on a thorough technical solar power tower site evaluation research, these zones were examined. To achieve the lowest levelized cost of electricity (LCOE), thermal energy storage and solar field size optimization are carried out. The Benban location, with outputs of 521,228.8 MWh and 0.1130 $/kWh, respectively, has the greatest produced energy and the lowest levelized cost of electricity, according to the findings. The ideal design for the solar power tower plant was shown by the results to be a solar multiple of 2.8 with a thermal energy storage of 8 h. The solar power tower plant's lowest levelized cost of electricity might then be reduced, in accordance with the optimum configurations, to 0.1057 $/kWh.

Thermal properties optimization of lauric acid as phase change material with modified boron nitride nanosheets-sodium sulfate for thermal energy storage

Lauric acid as phase change material is broadly used in thermal energy storage, whereas its poor heat transfer performance and low shape-stability hinder the practical application. In this work, a novel lauric acid/modified boron nitriding nanosheets‑sodium sulfate composite phase change material was fabricated by vacuum impregnation. During the fabrication process, sodium sulfate was introduced to improve the porosity and thermal conductivity of composite phase change material. The results show that the load capacity of lauric acid can reach to 83.5 wt% in lauric acid/modified boron nitride nanosheets‑sodium sulfate composite phase change material under the control of sodium sulfate. Besides, the thermal conductivity of lauric acid/modified boron nitride nanosheets-5 wt% sodium sulfate composite phase change material can reach up to 0.744 W/(m.K), which is 196.4 % higher than that of pure lauric acid, as well as the latent heat was increased by 7.49 % than that of composite phase change material without sodium sulfate. After 200 thermal cycles, lauric acid/modified boron nitride nanosheets‑sodium sulfate composite phase change material still has excellent phase change behavior and thermal stability. These properties show that sodium sulfate as a pore-forming agent has great significance for optimizing the thermal performance of composite phase change material. The excellent performance of lauric acid/modified boron nitride nanosheets‑sodium sulfate composite phase change material has a broad application prospect in the field of thermal energy storage and thermal management, etc.

A Review on Heat Transfer Enhancement of Phase Change Materials Using Fin Tubes

Latent heat thermal energy storage (LHTES) has received more and more attention in the thermal energy storage field due to the large heat storage density and nearly constant temperature during phase change process. However, the low thermal conductivity of phase change material (PCM) leads to poor performance of the LHTES system. In this paper, the research about heat transfer enhancement of PCM using fin tubes is summarized. Different kinds of fins, such as rectangular fin, annular fin, spiral fin, etc., are discussed and compared based on the shape of the fins. It is found that the longitudinal rectangular fins have excellent heat transfer performance and are easy to manufacture. The effect of fins on heat transfer enhancement is closely related to the number of fins and its geometric parameters.

Fire behaviour of EPDM/NBR panels with paraffin for thermal energy storage applications. Part 1: Fire behaviour

In this work the fire behaviour of elastomeric panels made of an Ethylene-Propylene Diene Monomer (EPDM) rubber filled with a shape-stabilized paraffin with a melting point of 28 °C and covered with a nitrile-butadiene rubber (NBR) envelope, developed for thermal energy storage applications, was investigated for the first time. The panels were prepared using four different flame retardants (FR) and in order to test their efficacy they were dispersed selectively only in the core material, or in the envelope or in both of them. Cone calorimeter and epiradiateur tests pointed out the efficacy of the clay used for the shape stabilization of paraffin and of the external NBR envelope. Moreover, it was possible to demonstrate that a flame retardant based on ammonium polyphosphate and aluminium diethyl phosphinate could achieve the best fire performances. It was also verified that the combination of the FR both in the core and in the envelope led to the best results thanks to the physico-chemical and chemical interactions between clay, talc, kaolin and silicon with ammonium polyphosphate. The best composition allowed to decrease the peak of the heat release rate (HRR) from 318 kW/m2 to 209 kW/m2 and the MARHE (parameter describing the intensity of the combustion over the whole process of thermal degradation) from 239 kW/m2 to 175 kW/m2. Moreover, regarding the ability to self-extinguish, the number of ignitions at epiradiateur test was increased from 4 to 8 within 5 min and the total combustion time from 391 to 288 s. The improvement of the fire behaviour of EPDM/NBR panels with paraffin makes possible future applications in the field of thermal energy storage of buildings.

N-Eicosane-Impregnated nonwoven phase change mats of electrospun Poly(ethylene oxide)/Poly(methyl methacrylate) blended fibers

The ever-increasing energy demand led scientists turn to more efficient, environmentally friendly, and renewable technologies. Phase change materials (PCMs) are gaining popularity in the field of passive thermal energy storage. In the current work, polyethylene oxide/poly (methyl methacrylate) (PEO/PMMA) electrospun fibers were employed as encapsulation matrices for n-eicosane and their physicochemical properties were tested, aiming to develop stable phase change fibers (PCFs). The effect of the n-eicosane content on the morphology and thermal properties of the form-stable PEO/PMMA/n-eicosane PCFs was extensively investigated by using X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA). The melting and crystallization enthalpy of PEO/PMMA/n-eicosane remained unchanged during the first and second cycle. After 30 heating-cooling cycles, the samples with 2 and 5 wt% n-eicosane exhibited inferior thermal reliability, while no temperature and enthalpy change were observed after the thermal cycling of PCF with 7.5 and 10 wt% n-eicosane content, thus rendering these systems suitable materials for thermal energy storage applications. The most promising system was the one containing a 10 wt% n-eicosane, due to the higher crystallization enthalpy (184 J/g) and the stabilization of the melting and crystallization peaks for all cycles. The degradation kinetics were investigated for n-eicosane, the pristine PEO/PMMA fibers and the PEO/PMMA/n-eicosane fibers with a 10 wt% n-eicosane content. Moreover, the Activation Energy (Ea) and the pre-exponential factor (A) were calculated using the Friedman and Vyazovkin methods whereas the reaction mechanisms were studied using the model fitting method.

Investigation on heat transfer enhancement of phase change material for battery thermal energy storage system based on composite triply periodic minimal surface

Phase change material (PCM), such as paraffin wax, has attracted extensive attention in the field of battery thermal energy storage (BTES) system. However, the latent heat of the PCM is unable to be efficiently utilized in the cases with fast thermal responses due to the low thermal conductivity. Triply periodic minimal surface (TPMS) has large surface area. In this study, the composite P-IWP type TPMS is proposed to enhance local heat transfer of the PCM. The thermal performance of the TPMS-based BTES system is studied by simulations and experiments. The results demonstrate that the composite P-IWP type TPMS sheet structure improves the efficiency of the PCM latent heat utilization. The enhanced heat transfer method based on traditional Kelvin type metal foam structure cannot make full use of the latent heat of PCM. Compared with the P type TPMS, the melting time of the PCM in the case of P-IWP type TPMS reduces by 30.8 %. The battery temperature in the case of P-IWP types TPMS decreases by 12.2 % and 11.3 % than that in the case of PCM-only at 1C and 2C discharge rates, respectively. In addition, the experimental results of the cycle process indicate that the TPMS-based BTES system reduces the temperature rise of the battery and increases the duration of the unit temperature drop.

Lipophilic Modified Hierarchical Multiporous rGO Aerogel-Based Organic Phase Change Materials for Effective Thermal Energy Storage.

In the field of thermal energy storage, organic phase change materials (PCMs) are widely used as functional materials to boost thermal applications. However, there is often a tradeoff between constructing shape-stable composite PCMs with high enthalpy value and those with low leakage rates. Here, we proposed a promising scheme to address this issue. A novel hydrogel consisting of reduced graphene oxide (rGO) and covalent organic framework (COF) was prepared via hydrothermal methods, and the rGO-COF ultralight aerogel with a hierarchical porous structure was formed after freeze-drying. The rGO-COF aerogel shows excellent absorption ability and affinity for organic solvents. It can sufficiently adsorb the molten organic PCMs, such as polyethylene glycol (PEG), and synthesize shape-stable composite PCMs with excellent leak resistance. The COF grown on the surface of rGO has a superior affinity for PEG, so rGO-COF aerogel shows an outstanding PEG loading rate of up to 96.1 wt %, which is 1.7 wt % higher than that of rGO aerogel. In addition, the COF effectively reduces the subcooling of PEG/rGO-COF with 20.3%, compared to PEG/rGO. Meanwhile, the prepared PEG/rGO-COF exhibits extremely high enthalpy and relative enthalpy efficiency (164.6 J/g, 97.4%). This demonstrates that a promising direction was highlighte for the preparation of high-enthalpy shape-stable composite organic PCMs in this work.

Experimental evaluation of IDA ICE and COMSOL models for an asymmetric borehole thermal energy storage field in Nordic climate

• A large-scale asymmetric borehole field was modelled in IDA ICE and COMSOL. • Simplification of asymmetric borehole field layout was investigated in 3-D model. • Borehole field models were validated by DTS-measured brine temperatures. • Validation of borehole field models showed good agreement. • Simplified-geometry borehole field model can reduce computational work. Appropriate modeling of borehole thermal energy storage (BTES) system is crucial for accurate prediction of BTES-coupled ground source heat pump performance with accessible computational load. This study aims to validate 3-D numerical models developed in IDA ICE 4.8 and COMSOL for a large-scale asymmetric borehole field consisting of 74 groundwater-filled boreholes with average depth of 310 m in Otaniemi, Finland. Comparisons were conducted between the detailed-geometry IDA ICE and COMSOL borehole field models and between the detailed-geometry and simplified-geometry IDA ICE borehole field models. All these models were validated by 1.5-years brine temperatures measured by temperature sensors and a distributed temperature sensing monitoring system. The results show the detailed-geometry IDA ICE model can estimate the BTES inlet and outlet brine temperatures as well as the COMSOL model. The average inlet and outlet brine temperature differences against the measurement data in the detailed-geometry IDA ICE and COMSOL models were both within 1 ℃. The simplified-geometry IDA ICE models can predict the borehole field inlet and outlet brine temperatures with a similar high accuracy (within 1 ℃ against the measurement) and can reduce the computational time by 72 % less than the detailed-geometry IDA ICE model.

Cloth-derived anisotropic carbon scroll attached with 2D oriented graphite layers for supporting phase change material with efficient thermal storage

Organic phase change materials (PCMs) have high heat storage density, but generally have low thermal conductivity, poor shape stability and poor optical absorption capacity, which limit their application in the field of solar heat storage and thermal management. In this study, a novel multistage two-dimensionally oriented porous carbon scroll was successfully designed. The carbon scroll was derived by rolling up the cloth-derived carbon sheet, which was attached with two-dimensional graphite layer, creating greatly enhanced thermal conductive paths along the cloth carbon sheet and the graphite layer. Phase change composites (PCCs) were obtained by vacuum impregnating paraffin into the porous carbon scrolls. The PCCs have excellent thermal conduction and heat storage properties, stabilized shapes and high photothermal conversion properties. In particular, the vertically arranged, multi-level and two-dimensional thermal conductive carbon layers have ensured the greatly improved anisotropic thermal conductivity of PCCs along the axis direction of the carbon scrolls. At a carbon filling content of 28.5 wt%, the axial and lateral thermal conductivity of the PCCs are 7.38 and 4.04 W K−1 m−1, and the thermal storage enthalpy is 157.2 J/g. These results show that the new PCCs have a lot of potential in the field of solar thermal energy storage and thermal management.

Experimental investigation on thermal management system with flame retardant flexible phase change material for retired battery module

Phase change material (PCM) cooling technology has attracted significant attention as an efficient battery thermal management strategy owing to its promising performance, especially in retired battery modules with the amplification of inconsistency and security risk generation. However, it has some limitations in practical applications, including the leakage of phase change ingredients, low thermal conductivity, and high flammability. Herein, a novel paraffin (PA)/EVA grafted with maleic anhydride (EVA-g-MAH)/expanded graphite (EG)/melamine (MA)/triphenyl phosphate (TPP) composite phase change material (MTPCM) was successfully prepared and utilised in a retired battery module. MTPCM3 with an MA/TPP ratio of 10/15 achieved multiple functions, such as leakage-proof capability, superior high thermal conductivity, and prominent flammable retardant performance (UL94-V0). Particularly, MTPCM demonstrated excellent total heat release (THR) and total smoke production (TSP) of 193.8 MJ/m2 and 7.8 m2, respectively. Furthermore, the application of MTPCM3 in 32650-type retired lithium iron phosphate battery modules effectively controlled the maximum temperature below 50 °C and maintained a temperature difference within 5 °C at a 3C discharge rate; this significantly prevented the heat accumulation of batteries and improved the temperature consistency of the retired battery during the long cycling process. This work suggests an efficient approach toward exploiting a multifunctional PCM for thermal management and energy storage fields.

Cellulose nanofibrous/MXene aerogel encapsulated phase change composites with excellent thermal energy conversion and storage capacity

Phase change materials (PCMs) have emerged as the most efficient thermal energy storage solutions due to their unique energy storage properties, but they inevitably have shortcomings such as easy leakage and single thermal energy conversion method. In order to solve these problems and expand the application scope of PCMs in the field of thermal energy storage, using cellulose nanofibers, MXene, PEG, and Fe3O4 as raw materials, combined with simple freeze-drying and vacuum impregnation techniques, a series of phase change composites (PCCs) with excellent solar/magnetothermal conversion properties were prepared. The solar-to-thermal conversion efficiencies of PCCs exceed 97.16%, and the lowest enthalpy value can still reach 151 J/g. When the content of Fe3O4 is 15%, the PCC exhibits good magnetothermal conversion ability, which can perform magnetothermal fast charging, and the PCC can rise from 17 °C to 85 °C in 130 s. Moreover, the PCCs have excellent thermal stability, which can remain stable below 350 °C, and the enthalpies value of the PCCs hardly decrease after 1000 cycles, showing great practical application value.

Paraffin@SiO2 microcapsules-based phase change composites with enhanced thermal conductivity for passive battery cooling

Phase change materials (PCMs) are potential candidates in passive thermal regulation and energy storage fields due to their high latent heat capacity around phase transition temperature. However, the leakage problem and low thermal conductivity are two obstructive factors for the extended application of PCMs. Herein, a series of paraffin@silicon dioxide microcapsules (Pa@SiO2)/graphene sheets (GS)/silicone rubber (SR) phase change composites (PCCs) were prepared. It is found that the inorganic SiO2 shell is conducive to enhancing the thermal conductivity of PCCs and the double encapsulation by the SiO2 shell and SR skeleton can restrict the leakage of liquid Pa during phase transition. With a Pa@SiO2 content of 70 wt%, the PCCs have a high latent heat of 126.1 J/g and enhanced thermal conductivity of 0.37 W m−1 K−1, which is 131.25% higher compared to that of pure SR. In addition, the introduction of graphene sheets further boosts the thermal conductivity of PCCs to 2.69 W m−1 K−1. The obtained PCCs lead to a surprising temperature decline of nearly 35 °C of a commercial lithium-ion battery during a high discharge rate (7.4 C). This work provides an efficient route to fabricate microcapsules-based PCCs for passive thermal regulation.

Influence of acid and alkali reaction system on the morphology and thermal properties of paraffin@SiO2 phase change microcapsules for heat storage

Phase change materials are preferred in the field of thermal energy storage in low-medium temperature. Paraffin@SiO2 microcapsules were prepared by a sol–gel method at an acid and alkali reaction system. The field emission scanning electron microscope, Fourier transform infrared spectroscope, differential scanning calorimetry, and thermogravimetric analyzer were adopted to investigate the effect of the acid and alkali reaction system on the morphology, latent heat, and thermal stability of PA@SiO2 microcapsules. In the acid reaction system, the particle size and latent heat of PA@SiO2 microcapsules are in the range from 15 to 30 μm and from 132 to 174 J/g, respectively. However, comparing with the acid reaction system, there was a remarkable reduction in the particle size and latent heat of microcapsules prepared in the alkali reaction system. The initial weightlessness temperatures of PA@SiO2 microcapsules were 40 °C higher than that of paraffin, indicating that the SiO2 shell was beneficial to the microcapsule structure.

Theoretical prediction and experimental investigation on nanoencapsulated phase change material with improved thermal energy storage performance

Nanoencapsulated phase change material (NanoEPCM) has the advantage of small size, large specific surface, good thermal reliability, and has broad application prospects in the field of thermal energy storage. However, most of the existing process conditions are relatively complicated, and it is difficult to prepare NanoEPCM with good microscopic morphology and excellent thermal properties. In this paper, a series of NanoEPCM with silicon dioxide (SiO 2 ) as the shell material and disodium hydrogen phosphate dodecahydrate (DHPD) as the core material are synthesized successfully by a facile sol-gel method. Firstly, the influence of the component ratio on the microscopic morphology of the NanoEPCM is predicted through a series of dissipative particle dynamics (DPD) mesoscopic simulation methods, as a result, the experimental parameters are determined initially. Furthermore, NanoEPCM possessed excellent properties is synthesized and characterized completely. The results show that all the NanoEPCM synthesized have relatively obvious spherical shape, which verifies the accuracy of the simulation results. In addition, the melting enthalpy and the encapsulation ratio of the obtained NanoEPCM achieves as high as 165.6 J/g and 70.1%, respectively, the maximum charging-discharging efficiency is 90.3%, and the supercooling is suppressed to 1.0 °C. The excellent microscopic morphology and thermal properties of NanoEPCM benefit from the reasonable component ratio and appropriate reaction conditions. Therefore, the NanoEPCM with excellent thermal properties is of great importance in the prospective thermal energy storage application. • DPD mesoscopic simulation method was employed to confirm the component ratios of the NanoEPCM. • A series of DHPD/SiO 2 NanoEPCM were synthesized successfully by a facile sol-gel method. • The obtained NanoEPCM had excellent microscopic spherical shape. • The supercooling of NanoEPCM was suppressed obviously.

Pore scale simulation for melting of composite phase change materials considering interfacial thermal resistance

• Implicit-enthalpy-based LBM with interfacial thermal resistance is proposed. • Porous structure is reconstructed by randomly generation-growth method. • The effective thermal conductivity of composite PCMs is evaluated. • The effect of natural convection, porosity and interface on melting are analyzed. The convective melting process and thermal performance of phase change materials (PCMs) incorporating porous skeleton in the one-side-heated rectangular cavity are investigated numerically in this work. A pore-scale lattice Boltzmann method (LBM) with implicit scheme is developed to explore the solid–liquid phase change process. The interfacial thermal resistance between the skeleton and PCMs is considered by interfacial conditions treatment. The random porous microstructure is generated by quartet structure generation set (QSGS) which is used to compute effective thermal conductivity in LBM. The validations of the current model are employed by the two-phase series conduction model and previous numerical results. The effects of porous structure, skeleton material, and thermal interfacial conditions on heat transfer characteristics are systematically investigated. The computational results show that the melting rate and effective thermal conductivity increase with the reducing porosity and the high thermal conductivity of the skeleton material accelerate the melting process. In addition, the consideration of interactions in the LBM leads to a significant difference. When the thermal interfacial resistance is set to be 1 × 10 −4 m 2 W/K, the temperature drop is very large in two-phase conduction, the melting rate decreases remarkably in the phase change process. The present simulation is also suitable for optimizing the porous structure to prepare various composite PCM in the thermal energy storage field.

Development of a new composite material for building energy storage based on lauric acid-palmitic acid-paraffin ternary eutectic and expanded perlite

Building thermal energy storage is critical to global sustainability as building energy consumption rises. In this study, a lauric-palmitic acid-paraffin ternary eutectic (LPP) was prepared from lauric acid, palmitic acid, and paraffin, and this LPP eutectic was adsorbed into expanded perlite (EP) via vacuum adsorption method to form a composite phase change material (LPP/EP). Leakage tests show that the maximum loading rate of EP on LPP is 75 %. Then, the chemical structure, crystal structure, crystalline morphology, micromorphology, and thermal property of LPP/EP were evaluated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Polarizing Optical Microscope (POM), scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). The results show that LPP/EP has superior crystal and chemical compatibility, LPP/EP melts at 31.78 °C and absorbs 117.34 J/g of latent heat, and LPP/EP has good thermal stability. Meanwhile, LPP/EP exhibits better thermal storage performance than EP. In addition, the 1000 melting-solidifying cycling experiment indicates that the LPP/EP has excellent durability. Therefore, the LPP/EP composite phase change materials will have an amazing performance in the field of building thermal energy storage.

Fluorinated microporous organic polymers for enhanced thermal energy storage

Knitting method has been widely used in the synthesis of microporous organic polymers (MOPs) because of its simple process and wide adaptability. In our study, microporous organic biphenyl (MOBP) and F-containing microporous organic fluorobiphenyl (MOFBP) were prepared in this way. The two polymers show large BET surface area (917 m2 g−1), pore volume (0.77 cm3 g−1) and favorable phase change materials (PCMs) capacities. Shape stable phase change composites were obtained using self-adsorption method. From differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD) results, the PCM composites have favorable encapsulation ratios, thermal stabilities and latent heats. For stearyl alcohol@ MOFBP (SA@MOFBP), the encapsulation ratio is 78.9 wt% and the latent heat reaches 194.3 kJ g−1. Moreover, all composites remained their thermal energy storage properties after 100 thermal cycles. These PCM composites have potential applications in the field of thermal energy storage.

Supercooling regulation and thermal property optimization of erythritol as phase change material for thermal energy storage

Erythritol has many advantages such as high latent heat, good stability, non-toxicity and abundance, which are extremely potential in the field of medium-temperature thermal energy storage. However, the application of erythritol in thermal energy storage is greatly restricts by high supercooling. Herein, sodium carboxymethyl cellulose (CMCNa) and hexagonal boron nitride (h-BN) are introduced to regulate the supercooling and thermal properties of erythritol. The crystal growth and nucleation process of erythritol is promoted effectively by CMC-Na and h-BN, as a result, the supercooling degree and solidification stability degree of erythritol is suppressed observably. According the results, while retaining the high latent heat of erythritol, the defect of supercooling of erythritol is effectively improved. The supercooling degree and solidification stability degree of erythritol are suppressed by 93% and 84%, respectively. Furthermore, the high latent heat, good thermal conductivity and excellent cycling thermal stability of erythritol composite phase change materials (ECPCM) are also available. This conclusion is important for supercooling regulation and thermal property optimization of erythritol, and indeed, can promote the utilization of erythritol in medium-temperature thermal energy storage.