Leakage Of Phase Change Materials Research Articles

Microsphere Structure Composite Phase Change Material with Anti‐Leakage, Self‐Sensing, and Photothermal Conversion Properties for Thermal Energy Harvesting and Multi‐Functional Sensor

AbstractThe low thermal conductivity and liquid melt leakage of phase change materials are long‐standing bottlenecks for efficient and safe thermal energy harvesting. Although high thermal conductivity materials combined with phase change materials can address the thermal conductivity problem, ensuring no leakage and no reduction in latent heat in the meantime remains challenging. Here, a strategy to synthesize microsphere‐structured phase change composites by encapsulating phase change materials in graphene via emulsion polymerization (no additional emulsifier) and chemical reduction is proposed. Multiple graphene sheets are connected to construct an efficient thermally conductive (increase 58.5 times in thermal conductivity) and electrically conductive network. The composite microspheres exhibit no leakage (<0.5%) and superior phase transition behavior after 1500 heating‐cooling cycles, and sense external environments such as temperature changes and water drops falling, allowing them to be engineered into devices for temperature monitoring. In addition, it converts electrical energy into thermal energy to achieve rapid temperature increases. The incorporation of polydopamine improves the photothermal efficiency of the phase change microspheres and senses light irradiation, offering a promising route to extend the single source of thermal energy. This method provides new insight into the photothermal integration and intelligent sensing of phase‐change materials.

Graphene aerogel stabilized phase change material for thermal energy storage

Phase change material (PCM) with thermal energy storage capacity has been a hot topic due to the advantages of satisfying the demand for energy storage, saving and conversion. In this work, graphene oxide (GO) was introduced to prepare a three-dimensional (3D) continuous network of graphene aerogel (GA) via a simple hydrothermal process, and the GA was further employed to pack polyethylene glycols (PEG). Benefited from the abundant porous structure and high specific surface area, the mass fraction of PEG in the composite PCM was up to 96.0 wt%. Besides, the heat latent of the composite was 223.2 J/g, illustrating a high energy storage density. Moreover, due to the crosslinking graphene skeleton and its inherent high thermal conductivity, the heat transfer rate was enhanced to 116% of the pure PEG. This work could simultaneously solve the drawbacks of leakage and low thermal conductivity of PCM. And the composite PCM could be considered as a clean, energy-saving and recycled material in the application of building heat preservation.

Preparation and application of composite phase change materials stabilized by cellulose nanofibril-based foams for thermal energy storage

The leakage issue and inferior heat conduction of organic phase change materials (PCMs) limit their actual applications. In the present study, cellulose nanofibril (CNF)-based foams were prepared as the porous scaffolds for polyethylene glycol (PEG) and paraffin wax (Pw) to prevent their leakage, and multiwalled carbon nanotubes (CNTs) were incorporated to improve the heat transfer performance. The prepared foams had low density (<67.3 kg/m3) and high porosity (>94.5 %). Selective chemical modifications of nanocellulose foams enhanced their shape-stability and compatibility with PCMs. The highly porous foam structure and favorable compatibility resulted in high PCM loading levels (93.63 % for PEG and 91.77 % for Pw) and negligible PCM leakage (<2 %). CNTs improved the heat transfer performance of PCMs, as evidenced by the improved thermal conductivities and boosted temperature rises during solar heating. Meanwhile, the composite PCMs exhibited improved thermal stability over the control. PEG-based composite PCM exhibited a phase change enthalpy of 143 kJ/kg with a melting temperature of 25.2 °C; Pw-based composite PCM exhibited a phase change enthalpy of 184 kJ/kg with a melting temperature of 53.4 °C. Novel PCM sandwich structures based on these composite PCMs and a thermoelectric generator were designed and displayed promising potential for solar energy harvesting and utilization.

Core-sheath phase change fibers via coaxial wet spinning for solar energy active storage

Using phase change fibers (PCFs) will help buffer the changes in ambient temperature, improve the utilization of natural energy, and ease the energy crisis. However, the poor solar energy absorption efficiency and leakage of phase change materials from PCFs seriously impaired their performance in practical applications. In this work, the core-sheath structured composite PCFs with excellent temperature regulation capability and high energy storage capacity were prepared by an economical and efficient coaxial wet spinning process for the first time. The infrared absorbers, Cs0·33WO3 (CWO), were incorporated into the hollow thermoplastic polyurethane (TPU) fibers to enhance solar energy absorption, and the paraffin wax (PW) was infused into the cavity of the composite fibers, giving rise to the formation of composite PW@TPU/CWO PCFs. The resultant PCFs showed a decrease in molten enthalpy and crystal enthalpy with the increasing of CWO contents, and the PCFs of PW@TPU/CWO5 can maintain a molten enthalpy of up to 90.47 J/g and an encapsulation rate of 69.93% that were higher than almost previous reports. The simulated house model under the coverage of PCFs fabric exhibited slight temperature variation and change rate, demonstrating the excellent heat storage and regulation capability of the as-prepared PCFs. The results show great potential applications in solar energy storage, heat storage and temperature regulation areas.

Using surface-modified UiO-66 with hierarchical pores to pack polyethylene glycol for phase change thermal energy storage: Experiment and molecular dynamics simulations

High performance composite phase change materials (PCMs) act a pivotal part in energy saving and renewable energy development as well as utilization. Herein, hierarchical porous metal–organic framework (MOF) UiO-66-CH3 with a high specific surface area (1086 m2/g) and large pore volume (1.22 cm3/g) was prepared to pack polyethylene glycol 2000 (PEG) organic PCM. The thermal property and stability of the synthesized composite PCMs were explored, and the mechanism was further analyzed by performing molecular dynamics (MD) simulations from an atomic view. The maximum loading of PEG/UiO-66-CH3 is 65 wt%, which is 62.5 % higher than that of single-scale microporous UiO-66. The crystallization ratio of PEG/UiO-66-CH3 exceeds 70 %. MD results prove that in hierarchical porous frameworks, the smaller pores prevent the leakage of PCMs, while the larger pores increase the adsorption of PCMs. Besides, the supercooling degree of PEG/UiO-66-CH3 decrease by 48 % than that of pure PEG, benefiting from the large specific surface area of UiO-66-CH3, which can provide a large number of heterogeneous nucleation sites for PCM. The simulation results reveal that the heat conduction property of UiO-66 and PEG was not affected by the compounding. The thermal conductivity of PEG/UiO-66-CH3 (0.496 W/(m·K)) is 32 % higher than that of SA/Cr-MIL-101-NH2 MOF-based material, while is 107 % higher than that of single-scale mesoporous PEG/MCM-41 composite. The composite PCM shows good thermal stability after 50 times thermal cycling. This work provides theoretical guidance for the synthesis of functional hierarchical porous composite PCMs with excellent thermal storage performance.

Application of carbon nanotube prepared from waste plastic to phase change materials: The potential for battery thermal management

Carbon nanotube (CNT), has been demonstrated as a promising high-value product from thermal chemical conversion of waste plastics and securing new applications is an important prerequisite for large-scale production of CNT from waste-plastic recycling. In this study, CNT, produced from waste plastic through chemical vapor deposition (pCNT), was applied as a nanofiller in phase change material (PCM), affording pCNT-PCM composites. Compared with pure PCM, the addition of 5.0 wt% pCNT rendered the peak melting temperature increase by 1.3 ℃, latent heat retain by 90.7%, and thermal conductivity increase by 104%. The results of morphological analysis and leakage testing confirmed that pCNT has similar PCM encapsulation performance and shape stability to those of commercial CNT. The formation of uniform pCNT cluster networks allowed for a large CNT loading into the PCM on the premise of free phase change, responsible for the high thermal conductivity inside the homogeneous phase. Thus, the resulting capillary forces retained a high latent heat capacity and suitable melting temperature and prohibited PCM leakage from the matrix to the outside during re-melting as the pCNT loading ratio increased. Therefore, the as-prepared pCNT-PCM composite is believed to have similar potential to cCNT and shows prominent performance as a flowable conductive filler for battery thermal management systems.

Regulating asphalt pavement temperature using microencapsulated phase change materials (PCMs)

The use of phase change materials (PCMs) to regulate pavement temperatures has been previously studied, with the most successful studies using porous aggregates to stabilize the PCMs. However, this technique can lead to issues with PCM leakage and low PCM content. A less studied method is the use of PCM microcapsules, which also presents challenges since most microcapsules are not strong nor stable enough to survive the high temperatures and compressive forces experienced during asphalt mixture production and placement. This work presents a study of the properties of a new commercial microcapsule type with robust walls and high thermal stability, that are expected to overcome the aforementioned issues. Results from differential scanning calorimetry and thermogravimetric analysis confirmed the microcapsules exhibited high latent heats (200 J/g) and are thermally stable below 400 °C. Additionally, approximately 90% of the capsules remained unbroken after being milled at 140 °C for 20 min, suggesting they are capable of withstanding the mixing and compaction stages of asphalt pavement construction. When PCM microcapsules were added to HMA, thermal cycling experiments showed that specimens containing 10 and 20 vol% PCM exhibited temperature lags of 5 to 10 °C from the control mixture, as they approached the PCM melting/freezing temperature. These results confirm the ability of microencapsulated PCMs to regulate asphalt pavement temperature. However, results from measurements conducted at 40 °C and 1 Hz showed a 75% reduction of the dynamic modulus in specimens containing PCM microcapsules, which could indicate that the addition of these materials also affect asphalt mixture stiffness.

Thermal, mechanical and microstructural properties of sustainable concrete incorporating Phase change materials

Over the past two decades, there has been a significant increase in Buildings’ energy consumption. This rise led to a noticeable leap in operating costs. Subsequently, a need to find novel ways to lower the energy demand in buildings was crucial. Advances in material technology have proven that incorporating phase change materials (PCM) into concrete is one of the ways to tackle energy consumption problems. Depending on the temperature that PCM is exposed to, energy can be absorbed and released easily. This study introduces a set of experiments adopting different quantities of microencapsulated paraffin wax; 1%, 3%, 5%, 7%, and 10% incorporated into normal strength concrete (NSC), high strength concrete (HSC), normal lightweight concrete (LWC) and high strength lightweight concrete (HSLWC). Hence, fresh, hardened, and thermal properties of produced concrete were explored. The hardened properties comprise both strength and sorptivity tests. Additionally, microstructure analysis was investigated. Concrete thermal performance was identified by both thermal conductivity (K-Value) and analyzing the heat transfer rate. The results showed that increasing PCM amount led to reducing the thermal conductivity and increasing heat capacity, which in turn enhanced concrete thermal performance. However, the microstructural analysis showed that many capsules are damaged during the mixing process, releasing their paraffin wax filling into the surrounding matrix, which consequently causes a significant reduction in strength. Anyhow, the prevention of PCM leakage during mixing and improving ITZ in concrete were both achieved using HSC.

A Review of Composite Phase Change Materials Based on Biomass Materials.

Phase change materials (PCMs) can store/release heat from/to the external environment through their own phase change, which can reduce the imbalance between energy supply and demand and improve the effective utilization of energy. Biomass materials are abundant in reserves, from a wide range of sources, and most of them have a natural pore structure, which is a good carrier of phase change materials. Biomass-based composite phase change materials and their derived ones are superior to traditional phase change materials due to their ability to overcome the leakage of phase change materials during solid–liquid change. This paper reviews the basic properties, phase change characteristics, and binding methods of several phase change materials (polyethylene glycols, paraffins, and fatty acids) that are commonly compounded with biomass materials. On this basis, it summarizes the preparation methods of biomass-based composite phase change materials, including porous adsorption, microencapsulation based on biomass shell, and grafting by copolymerization and also analyzes the characteristics of each method. Finally, the paper introduces the latest research progress of multifunctional biomass-based composite phase change materials capable of energy storage and outlines the challenges and future research and development priorities in this field.

Thermo-Mechanical Behavior of Novel EPDM Foams Containing a Phase Change Material for Thermal Energy Storage Applications.

In this paper Ethylene Propylene Diene Monomer rubber (EPDM) foams were filled with different amounts of paraffin, a common phase change material (PCM) having a melting temperature at about 70 °C, to develop novel rubber foams with thermal energy storage (TES) capabilities. Samples were prepared by melt compounding and hot pressing, and the effects of three foaming methods were investigated. In particular, two series of samples were produced through conventional foaming techniques, involving physical (Micropearl® F82, MP, Lehvoss Italia s.r.l. Saronno, Italia) and chemical (Hostatron® P0168, H, Clariant GmbH, Ahrensburg, Germany) blowing agents, while the salt leaching method was adopted to produce another series of foams. Scanning electron microscopy (SEM) and density measurements showed that MP led to the formation of a closed-cell porosity, while a mixed closed-cell/open-cell morphology was detected for the H foamed samples. On the other hand, foams produced through salt leaching were mainly characterized by an open-cell porosity. The qualitative analysis of paraffin leakage revealed that at 90 °C only the foams produced through salt leaching suffered from significant PCM leakage. Consequently, the thermo-mechanical properties were investigated only in samples produced with H and MP. Differential Scanning Calorimetry (DSC) analysis revealed that EPDM/paraffin foams were endowed by good TES properties, especially at higher PCM contents (up to 145 J/g with a paraffin amount of 60 wt%). Tensile and compressive tests demonstrated the addition of the PCM increased the stiffness at 25 °C, while the opposite effect was observed above the melting temperature of paraffin. These results suggest that the EPDM foams produced with H and MP show an interesting potential for thermal management of electronic devices.

Thermal behavior analysis of wood-based furniture applied with phase change materials and finishing treatment for stable thermal energy storage

In recent times, indoor environments have become increasingly important for occupants who spend most of their time indoors. The use of furniture, which occupies a large specific surface area in interior spaces, is expanding. Medium-density fiberboard, particleboard, and plywood are generally used as wood-based furniture materials, and these materials require surface-finishing treatment to maintain quality and efficiency. Among various types of finishing treatments, low-pressure melamine (LPM) coating can be applied to other materials using the hot pressure process. The coating provides an exterior pattern, reduces the emission of pollutants, and resists moisture. However, when a furniture item is fixed in environment with a large temperature difference, water vapor condensation is likely to occur. In particular, the materials of a built-in furniture item require to be improved. As the use of indoor furniture increases, various functions are required. In this study, phase change materials (PCMs) were applied to wood-based furniture materials to reduce their sensitivity to temperature changes and provide effective heat storage properties. This application process was performed using three types of materials, and the results indicated high enthalpy and thermal storage performance. The PCM/wood material of the surface of the specimen required 187 min to reach the peak temperature at a high ambient temperature and exhibited reduced temperature sensitivity. Moreover, LPM-based finishing treatment is an effective method to prevent PCM leakage.

High-performance thermal energy storage and thermal management via starch-derived porous ceramics-based phase change devices

Low thermal conductivity and leakage of phase change materials (PCMs) have severely limited their applications in thermal energy storage and thermal management of electronic devices. Here, we propose starch-derived porous SiC ceramics to achieve high thermal conductivity and prevent leakage of PCMs simultaneously. Porous SiC ceramics with high thermal conductivity of 30 W/m-K at high porosity of 80% are obtained, benefiting from directional pore structures and dense grains enabled via facile directional freeze-drying of starch combined with liquid silicon infiltration technology. Thermal conductivity and thermal energy storage density of SiC/paraffin composite PCMs (CPCMs) attenuated only slightly by 2.75% and 2.80% after 500 repeated heating-cooling cycles, respectively, confirming their longevity and good stability. The phase change enthalpy achieves 331.56 J/g with high thermal conductivity of 24.27 W/m-K maintained by replacing paraffin with LiOH-LiF eutectics. When applying into transient cooling of high-power chips, the chip temperature is 10 ℃ lower if replacing traditional copper by porous SiC/paraffin CPCMs as a cooling medium. Our work demonstrates a promising route to realize efficient thermal energy storage and thermal management of high-power electronics via starch-derived porous ceramics-based phase change devices.

A Battery Thermal Management System Coupling High-Stable Phase Change Material Module with Internal Liquid Cooling

In this work, we develop a hybrid battery thermal management (BTM) system for a 7 × 7 large battery module by coupling an epoxy resin (ER)-enhanced phase change material (PCM) module with internal liquid cooling (LC) tubes. The supporting material of ER greatly enhances the thermal stability and prevents PCM leakage under high-temperature environments. In addition, the other two components of paraffin and expanded graphite contribute a large latent heat of 189 J g−1 and a high thermal conductivity of 2.2 W m−1 K−1 to the PCM module, respectively. The LC tubes can dissipate extra heat under severe operating conditions, demonstrating effective secondary heat dissipation and avoiding heat storage saturation of the module. Consequently, during the charge-discharge tests under a 40 °C ambient temperature, the temperature of the PCM-LC battery module could be maintained below 40.48, 43.56, 45.38 and 47.61 °C with the inlet water temperature of 20, 25, 30 and 35 °C, respectively. During the continuous charge-discharge cycles, the temperature could be maintained below ~48 °C. We believe that this work contributes a guidance for designing PCM-LC-based BTM systems with high stability and reliability towards large-scale battery modules.

Highly thermal conductive phase change composites containing Ag-welding graphene framework with excellent solar-thermal conversion and rapid heat transfer ability

The anisotropic three-dimensional (3D) Ag-welding graphene framework prepared by unidirectional ice-templating freezing casting, was used to encapsulate polyethylene glycol (PEG) as phase change material (PCM) composite in this work. Arising from the decreased interfacial thermal resistance (ITR) in graphene skeleton by Ag-welding and the vertically oriented graphene skeleton as phonon transfer paths, the obtained PCM composite exhibited a high thermal conductivity of 4.3 W m−1 K−1 at graphene loading of ∼6.25 vol%, which improved significantly the heat transfer rate during the heat charging/discharging processes. Meanwhile, the graphene framework gave the PCM composite an excellent solar-thermal conversion ability, which could be further enhanced by Ag-welding strategy. Besides, the 3D porous framework with huge capillary and surface tension forces effectively improved the shape stability and avoided leakage of PCM, with meanwhile remaining high energy storage capacities (147.4–165.9 J g−1). Therefore, the Ag-welding 3D graphene framework reveals the high potential to encapsulate PCM using in solar-thermal conversion field.

All lignin-based sponge encapsulated phase change composites with enhanced solar-thermal conversion capability and satisfactory shape stability for thermal energy storage

To promote the high-value utilization of lignin, a novel, all lignin-based chemically crosslinked sponge (CCL) was prepared and used to encapsulate phase change materials (PCMs) to solve problems associated with PCM leakage in practical application. In a straightforward, one step vacuum impregnation method, myristyl alcohol (MA), n-docosane (C22), and polyethylene glycol (PEG) phase change materials were encapsulated in the CCL sponges that were used as supporting material to prepare CCLPCMs, which were named as MA/CCL, C22/CCL, and PEG/CCL, respectively. Benefiting from the strong capillary action provided by the unique 3D continuous porous structure of the CCL, the mass loading of PCMs in the corresponding CCLPCMs are reached up to 93.1 ± 1.5 %, 90.2 ± 1.2 %, and 91.2 ± 0.6 %, respectively. It is also worth noting that η values of the corresponding CCLPCMs reached 99.4 ± 0.9 %, 100.9 ± 1.0 %, and 99.7 ± 1.0 %. The CCLPCMs showed excellent encapsulation capabilities, thermal reliability after 300 heating and cooling cycles and high solar-to-heat conversion capability over 30 cycles. These results provide a fresh, green, sustainable, and promising strategy to promote high-value utilization of lignin and design shape stability PCMs for heat energy storage.

Energy dissipation in phase change salogels under shear stress

Phase change salogels are physical networks designed to shape stabilize salt hydrate phase change materials (PCMs) and inhibit the leakage of molten PCM. In contrast to chemically crosslinked gels, salogels can restructure by breaking of prior and reforming of new bonds. Therefore, salogels are susceptible to dissipate energy during deformations due to the nature of physical bonds. In the present work, different concentrations of diethylenetriamine, as a physical crosslinker, were added to a constant concentration of polyvinyl alcohol (PVA) in a high-salinity environment of a fluid inorganic PCM (lithium nitrate trihydrate), and network viscoelasticity was studied using oscillatory rheology. The energy dissipated was calculated by computing the area inside Lissajous stress-strain curves performed at various strain amplitudes and a constant frequency of 1 rad/s. The results of energy dissipation as a function of salogels' crosslinker concentration has a minimum when crosslinker concentration is ≅ 5–7 wt%. tes with the maximum point in the salogels' shear modulus graph. Lissajous plots' intracycle moduli analysis were used to quantify the observed non-linear behavior within a cycle of oscillation and proposed internal structure changes during deformation. Three regions based on the variation of dissipation energy with strain amplitudes (γ) for each salogel network were identified: region I (γ < ∼10%): linear viscoelastic region, region II (∼10% < γ < ∼100%): intermediate strain region with shear thickening behavior and, region III (γ > ∼100%): large deformation region with shear thinning behavior. Our results show that while most bonds are breaking at high strain amplitudes, there is a possibility of interchain reformation at intermediate shear strains due to the polymer chain alignment, which can slow down energy dissipation in this region. This study enhances the fundamental understanding of salogels’ microstructural response to non-linear deformation, which would benefit energy storage applications subjected to large deformations such as conformable packs and pillows.

Thermal and Mechanical Properties of Mortar Incorporated with Phase Change Materials (PCMs)

Phase change materials (PCMs) integration into cement mortar is among the new studies of interest regarding modern energy-saving techniques and developing the thermal properties in buildings. This study aims to integrate microencapsulated-PCMs (micro-PCMs) with cement mortar at 0, 5, 10, and 15% to replace natural sand for thermal properties improvement of the building envelope. In addition, the effect of using micro-PCMs on mechanical, thermal properties, and PCMs leakage problems were studied. The cement mortars incorporated with micro-PCMs were investigated by scanning electron microscopy (SEM), thermal conductivity, and mechanical properties as (compressive, flexural, and tensile). The results indicate a decreasing trend of thermal conductivity values with the increase in PCMs content in the cementitious system with the percentages of 11, 21, and 30% for 5, 10, and 15% PCMs, respectively. Similarly, mechanical properties results also confirmed that integrating incorporating mortars with PCMs resulted in the reduction in the compressive strength by 22, 31, and 46%, respectively. Therefore, using the PCMs with cement mortar can build envelope applications to store thermal energy, provide the indoor temperature at a comfortable range, and reduce the consumption energy in buildings.

Multi-scale analysis of mechanical and thermal behaviour of mortars incorporating phase change materials

This study presents the influence of phase change materials (PCMs) on the cyclic behaviour of mortars. A multi-scale analysis comprising mechanical and thermal tests was used to explain the phenomena involved. Mechanical and thermal cyclic tests were performed on four configurations of mortars containing 0%, 5%, 8%, and 10% of PCMs. It was revealed that mechanical cyclic loading did not significantly affect the resistance of mortars contrary to thermal solicitations. Indeed, it was shown that the incorporation of PCMs improved the thermal capacity of the mortars. However, severe degradation of the heat capacity and enthalpy was noticed after the temperature cycles. The physicochemical characterisation tests confirmed a moderate structural degradation, which primarily occurred in the initial cycles. Regarding the thermal cycles, scanning electron microscopy (SEM) and calorimetry characterisations corroborated the leakage of PCMs into the cement matrix, which was responsible for the degradation of latent heat. Finally, it was observed that the PCM–mortars resisted mechanical cyclic solicitations, at least up to 1000 cycles; however, they were still sensitive to repeated variations in temperature.

Phase Change Material with Gelation Imparting Shape Stability.

Blending two gelators with different chemistries (12-hydroxystearic acid and a bis-urea derivative, Millithix MT-800) was used to impart shape stability to CrodaTherm 29, a bio-based phase change material (PCM), melting/crystallizing at near-ambient temperature. The gelators immobilized the PCM by forming an interpenetrating fibrillar network. 15 wt % concentration of the gelators was found to be effective in preventing liquid PCM leakage. In order to improve the mechanical properties and thermal conductivity (TC) of the PCM, gelation of suspensions of multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GnPs) in a molten material was done at concentrations exceeding their percolation thresholds. Compared to pristine PCM, the gelled PCM containing 3.0 wt % of GnPs demonstrated a shorter crystallization time, ∼1.5-fold increase in strength, improved stability, and ∼65% increase in TC. At the same time, PCM filled with up to 0.6 wt % of MWCNTs had diminished strength and increased leakage with a slight TC improvement. Gelation of PCM did not significantly alter its thermal behavior, but it did change its crystalline morphology. The developed shape-stable PCMs may have a wide range of applications in ambient temperature solar-thermal installations, for example, temperature-controlled greenhouses, net zero-energy buildings, and water heaters.

Solar-thermal energy conversion and storage of super black carbon reinforced melamine foam aerogel for shape-stable phase change composites

Thermal energy harvesting and storage with phase change materials (PCMs) have attracted extensive exploration in solar-thermal utilization. Solving leakage issue of PCMs and improving the energy absorption, storage and transport are facing great challenges. As a typical aerogel with porous structure and strong light absorption, carbon aerogel (CA) becomes an attractive support material for PCMs. In this work, the carbon aerogels reinforced melamine foam (CA/Foam) were prepared by sol-gel polymerization, freeze drying and carbonization. To further optimize the pore structure and optical properties, CO 2 activation is implemented to obtain the super black reinforced melamine foam, which is named as activated CA/Foam (ACA/Foam). After vacuum adsorption of PW, the prepared paraffin wax/activated carbon aerogel/foam (PW/ACA/Foam) maintains high thermal storage density of 143.4 J/g and shows excellent thermal stability, which can effectively solve the shortcoming of PCMs leakage due to rich pore structure. Encouragingly, the photothermal conversion efficiency of PW/ACA/Foam composite material can reach 92.1% with 5% weight fraction of resorcinol and formaldehyde in the precursor solution. The thermal conductivity of PW/ACA/Foam is 0.71 W/(m·K), 97.2% higher than pure PW, which will be the potential material for composite PCMs applied in solar energy utilization. • The cracking and leakage issues of PCMs can be solved by carbon aerogel. • The absorptance of ACA/Foams can be above 94% among 200 nm–800nm. • The excellent shape stability and thermal reliability can be achieved by ACA/Foams. • Outstanding photothermal conversion performance, thermal conductivity and high latent heat is practical.