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•Challenges and mechanisms for engineering the thermal parameters of PCMs were summarized.•Design techniques of novel composite PCMs were systematically analyzed.•Recent advanced ...applications of composite PCMs were highlighted.•Developing multifunctional composite PCMs is demanding for practical applications.
The design of composite phase change materials (PCMs) for thermal energy storage has attracted increasing attention owing to their high latent heat storage capability, enhanced thermal transfer performance, and low volume variation in addition to being seepage free. This review aims to provide techniques for engineering the thermal parameters of composite PCMs (e.g., latent heat, thermal conductivity, durability, and thermal stability) for several advanced large-scale applications and for producing desired thermophysical, chemical, and mechanical properties. In addition, approaches and materials employed for composite synthesis are described. Challenges and factors influencing the thermal energy storage performance of composite PCMs are also analyzed. Furthermore, the recent advanced applications of composite PCMs (including medical, building, electronics, solar, and energy storage and conversion) as well as the potential for producing energy storage and conversion materials are indicated. This report is likely to provide a foundation for designing multifunctional organic composite PCMs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The thermal conductivity of MA-SA was improved by 117.65% compared to that of the pristine value with high storage capacity using mesoporous N-doped porous carbon matrix as a supporting material.
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•Two simple strategies were employed for supporting materials synthesis.•Mesoporous N-doped carbons/MA-SA shape stabilized PCMs were prepared.•The loading of PCM in the composite PCMs could attain 88 wt% with high stability.•The phase change enthalpy of the composite PCMs could achieve 164.33 kJ/kg.•The composite attained enhanced thermal conductivity (up to 117.65%).
A systematic mesoporous N-doped carbons/myristic acid-stearic acid composite materials with improved thermal conductivity, energy storage density and shape stable performance were prepared by encapsulating myristic acid-stearic acids (MA-SA) eutectic mixture into porous carbon matrixes derived from two synthesis strategies. The effect of synthesis strategies and the N species present in porous carbons on the microstructure and thermal energy storage properties of composite phase change materials were studied by various characterization techniques. The results indicated that N-doped porous carbons derived from in situ (NPC) had maximum of up to 88 wt% PCM loading with a melting latent heat of 164.33 ± 0.29 kJ/kg, which was up to 45.69% higher than that of composite PCMs by post synthesis route (MGC/MA-SA). Factors, like pore characteristics, capillary force, surface tension and additional interaction with N species present in carbon matrix played vital roles for encapsulation of MA-SA to the pores of supporting materials. Notably, NPC/MA-SA composite materials exhibited excellent thermal conductivity, 117.65% higher than pristine PCM, while 74.59% for MGC/MA-SA. The content, homogeneous distribution and graphitic nature of N as well as the interconnected porous carbons improves the heat transfer pathways in the composite PCMs during phase change process. All the prepared samples were thermally and chemically compatible even after 100 times thermal cycling, confirming that the prepared composite materials were a promising candidates for thermal management system in a medium phase transition temperatures like domestic solar hot water supply and air-conditioning purposes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Currently, numerous efforts are being made to develop shape-stabilized composite phase change materials (PCMs) to respond to unbalanced renewable energy storage systems. In this study, we engineered ...hybrid materials based on commercially available and environmentally friendly biochar derived from bamboo and multiwalled carbon nanotubes (CNTs) via a one-step hydrothermal method. The organic liquid n-dodecane was used as the energy storage material. The hybrid material provides favorable morphological and interconnected framework structures for PCM encapsulation and energy storage capacity in the composite PCMs. The PCM loading capacity of biochar, biochar-CNT, and CNTs reached 51.3%, 70.6%, and 83.2% with latent heat of 93.4 ± 1.1, 127.3 ± 1.1, and 152.3 ± 1.3 J/g, respectively. The integration of CNTs with biochar positively affected the latent heat storage capacity of the composite PCMs compared with that of the composite PCMs without CNTs. The pristine biochar exhibited a low PCM loading ratio and latent heat compared with biochar-CNTs and CNTs, presumably due to the limited pore space and strong intermolecular interaction between the reactive functional groups and PCM. Meanwhile, the obtained composite PCMs exhibited outstanding shape and thermal stabilities and chemical compatibilities. This synthesis strategy is expected to create a platform for fabricating biochar-based multifunctional PCMs for desired applications.
•A biochar-integrated multiwalled carbon nanotube hybrid was designed and employed as n-dodecane support.•The hybrid material provides a suitable microstructure for high phase change material (PCM) loading.•PCM introduced into pristine biochar and biochar-CNT revealed a heating enthalpy of 127.3 J/g and 152.3 J/g, respectively.•The composite PCMs displayed high chemical compatibility and shape/thermal stabilities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To obtain high thermal performance composite phase change materials (PCMs), various other supporting materials have been utilized to encapsulate organic PCMs. In this study, four carbon materials ...(biochar, activated carbon, carbon nanotubes, and expanded graphite) were introduced to support heptadecane. The composite PCMs were designed using vacuum impregnation techniques. The structural stability, chemical compatibility, thermal stability, and thermal energy storage capacity of the as-prepared materials were systematically characterized using differential scanning calorimetry, Fourier-transform infrared spectroscopy, etc. Among the supporting materials, expanded graphite had a high PCM content of 94.5%, whereas it was low for biochar-supported PCM (25.7%). Meanwhile, the latent heat storage capacity ranged from 53.3 J/g to 195.9 J/g. It was observed that the intermolecular interactions between the PCM and supporting materials and the surface functionality of the encapsulating agents play a leading role in the thermal performance of the composite PCMs. Furthermore, pore structures such as specific surface area, total pore volume, and pore size distribution have a combined effect on the crystallinity of heptadecane in the composite PCMs. The study will provide insight into developing and designing carbon-based composite PCMs for heat-storage purposes.
•Different carbon materials were employed to develop composites phase change materials (PCMs).•Biochar supported composite exhibited high shape/thermal stabilities.•Expanded graphite supported PCM revealed high latent heat (195.9 J/g).•The surface functionality of the supporting matrices plays a vital role in thermal properties.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Phase change enthalpy and thermal conductivity are the two essential parameters for practical applications of shape-stabilized phase change materials (ss-PCMs). Herein, hierarchical three-dimensional ...(3D) reduced graphene porous carbon support PCMs have been successfully synthesized by carbonizing a graphene oxide@metal–organic framework (GO@MOF) template, which simultaneously realizes large phase change enthalpy and high thermal conductivity. During the carbonization process, MOFs were converted into hierarchical porous carbons, whereas GO was reduced to high-thermal-performance reduced graphene (rGO). Thus, a hierarchical 3D porous carbon structure with high porosity and large specific surface area was obtained, which provided a suitable condition for encapsulating PCMs. Furthermore, the pores of carbon stabilized the PCMs by capillary force and surface tension. The interaction between the PCM molecule and rGO significantly decreased the interfacial thermal resistance and made the composites reveal high thermal conductivity. Furthermore, the 3D network structure promoted the stretching and crystallization characteristics of the stearic acid molecule in the confined pore space, which enhanced the heat release efficiency. Compared with the rGO/MOF-5-C support, the hierarchical 3D structure of rGO@MOF-5-C revealed a thermal conductivity of 0.60 ± 0.02 W m–1 K–1, which was 27.7% improvement, with large phase change latent heat of 168.7 J g–1, which increased by 18.5%. Additionally, the obtained ss-PCMs showed transient thermal response and good durability, indicating its promising potential in thermal energy storage application.
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IJS, KILJ, NUK, PNG, UL, UM
Mesoporous carbons with high porosity, large specific surface areas and a certain degree of graphitization were facilely prepared via carbonization of sucrose at different temperatures of 700 °C ...(C-700), 800 °C (C-800) and 900 °C (C-900) and were used as supporting frameworks for phase change materials (PCMs) loading paraffin. The as-prepared carbons had high loading capacity of paraffin as demonstrated by leakage tests. The paraffin loading capacity of C-700, C-800 and C-900 reached up to 88.8 wt%, 91.7 wt% and 90.6 wt% respectively without leakage, and the corresponding latent heats were 103.0%, 104.5% and 102.9% that of pure paraffin with the same actual paraffin amount, showing improved latent heat. TG results showed that the as-prepared PCMs had better thermal stability and their good thermal cycling stability was demonstrated by thermal cycling tests after 50 cycles. Furthermore, the thermal conductivity of the composite PCMs improved to a certain degree compared with that of pure paraffin.
Phase change composites are in high demand in thermal management systems. Various supporting materials, including nanocomposites, have been employed to develop shape-stable phase change materials ...(PCMs). As the reliability of most composite materials has mostly been studied right after the preparation with specific thermal cycling measurements, it is difficult to analyze the long-term leakage-resistance capability and energy retention capacity. Additionally, achieving multifunctional phase change composites is a significant challenge for single supporting materials. Herein, we provide a follow-up report on the thermal performance of hybrid material-supported n-alkane after a storage time of one year and 50 heating/cooling cycles. The interconnected hybrid material composed of a metal–organic framework (MOF) and graphite improved the shape/thermal stability of tetradecane (TD). The as-synthesized MOF/graphite/TD composites exhibited a high latent heat retention capacity of 84.2%, low leakage rate of 1.25%, and high PCM loading capacity, making them suitable for thermal management applications, such as industrial waste heat recovery systems. Furthermore, the intermolecular interactions and capillary forces between the hybrid materials and TD provided high stability and compatibility. Therefore, the as-prepared hybrid material fabricated in this study can be important in the development of multidirectional composite PCMs with comprehensive thermal characteristics.
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•Phase change composites were prepared by infiltrating MOF/graphite support with tetradecane.•The composite materials revealed high durability after a one-year storage time and 50 phase change cycles.•The composite PCMs exhibited high latent heat retention (84.2%) and loading capacity.•The leakage resistance was improved by 156% compared with pristine graphite/tetradecane.•The favorable 3D structure and capillary force play a vital role in the infiltration process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Cost-effective and eco-friendly biochar-based composite PCMs were developed.•Biochar/n-alkane composites show high thermal stability and compatibility.•The composites exhibit high ...infiltration ratio and heating enthalpies.
Biochar, also named biocarbon, is a solid particulate material produced from the thermal decomposition of biomass at moderate temperatures. It has progressively become the topic of scientific interest in energy storage and conversion applications due to its affordability, environment friendliness, and structural tunability. In this study, biochar (obtained 600 °C pyrolysis) was introduced as phase change materials (PCMs) support. Three different n-alkanes (such as dodecane, tetradecane, and octadecane) are used as PCMs. The PCMs were infiltrated in the biochar network via the vacuum impregnation method. Among the biochar/n-alkane composites, one from octadecane exhibited a high latent heat storage capacity of 91.5 kJ/kg, 15.7 % and 25.9 % higher than that of dodecane and tetradecane-based composites, respectively. The molecular length of the PCMs and intermolecular interaction between the functional groups play an imperative role. The infiltration ratio of PCM in the biochar reached 50.1 % with improved thermal stability and chemical compatibility. This is attributed to the favorable morphological and structural properties (e.g., large BET surface area and mesopore structure) of the biochar that resides the n-alkanes found in the nanosized chain length. Hence, this report will lay a foundation for the application of biochars in thermal energy management systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
High‐value‐added biomass materials like biocarbon are being actively pursued integrating them with soft materials in a broad range of advanced renewable energy technologies owing to their advantages, ...such as lightweight, relatively low‐cost, diverse structural engineering applications, and high energy storage potential. Consequently, the hybrid integration of soft and biomass‐derived materials shall store energy to mitigate intermittency issues, primarily through enthalpy storage during phase change. This paper introduces the recent advances in the development of natural biomaterial‐derived carbon materials in soft material assembly and its applications in multidirectional renewable energy storage. Various emerging biocarbon materials (biochar, carbon fiber, graphene, nanoporous carbon nanosheets (2D), and carbon aerogel) with intrinsic structures and engineered designs for enhanced enthalpy storage and multimodal applications are discussed. The fundamental design approaches, working mechanisms, and feature applications, such as including thermal management and electromagnetic interference shielding, sensors, flexible electronics and transparent nanopaper, and environmental applications of biocarbon‐based soft material composites are highlighted. Furthermore, the challenges and potential opportunities of biocarbon‐based composites are identified, and prospects in biomaterial‐based soft materials composites are presented.
This review provides up‐to‐date design progress in biomass‐derived materials in soft materials assembly for applications in enthalpy storage and renewable energy technology development. It highlights structural engineering, mechanisms, and advancements in various application areas, such as thermal management, electronics, and environment. This is expected to guide a deeper understanding of advanced biocarbon‐based composite construction for sustainable energy development and management.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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•The surface S-vacancies acted as an electronic reservoir and enriched electrons.•The amorphous carbon in the nanocomposite was employed as photo-sensitizers.•The S-vacancies and the ...carbon enhanced the photo-absorption and photo-responsibility.
Carbon -MoS2−x@CdS (C-MoS2−x@CdS) core-shell nanostructures with controlled surface sulfur (S) vacancies were prepared via a glucose assisted hydrothermal growth method. The glucose acted as a reducing agent of C-MoS2−X to partially reduce Mo4+ ions to Mo3+ and served as a carbon source to insert the amorphous carbon into the layered MoS2−X simultaneously. The presence of Mo3+ result in the surface S-vacancies, which can provide more additional active sites and enhance the photocatalytic performance. Moreover, the inserted carbon in layered MoS2−X enhanced the electron mobility and decreased the resistance electron transfer. Density functional theory (DFT) calculation confirmed that the surface S-vacancies and the amorphous carbon increase the projected density of states at the conduct band edge, which could enhance the photo-absorption and photo-responsibility. The result is consistent with the photocatalytic H2 production experiment. C2-10%MoS2−x@CdS presented a high H2 evolution rate of 61,494 μmol h−1 g−1 under visible light irrigation (λ ≥ 420 nm), which is 1.98 times and 158 times higher than that of sample without S-vacancies (10%MoS2@CdS) and pure CdS, respectively.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
