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Journal = Materials
Section = Energy Materials

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40 pages, 9273 KiB  
Review
Revisiting Intercalation Anode Materials for Potassium-Ion Batteries
by María José Piernas-Muñoz and Maider Zarrabeitia
Materials 2025, 18(1), 190; https://doi.org/10.3390/ma18010190 (registering DOI) - 4 Jan 2025
Abstract
Potassium-ion batteries (KIBs) have attracted significant attention in recent years as a result of the urgent necessity to develop sustainable, low-cost batteries based on non-critical raw materials that are competitive with market-available lithium-ion batteries. KIBs are excellent candidates, as they offer the possibility [...] Read more.
Potassium-ion batteries (KIBs) have attracted significant attention in recent years as a result of the urgent necessity to develop sustainable, low-cost batteries based on non-critical raw materials that are competitive with market-available lithium-ion batteries. KIBs are excellent candidates, as they offer the possibility of providing high power and energy densities due to their faster K+ diffusion and very close reduction potential compared with Li+/Li. However, research on KIBs is still in its infancy, and hence, more investigation is required both at the materials level and at the device level. In this work, we focus on recent strategies to enhance the electrochemical properties of intercalation anode materials, i.e., carbon-, titanium-, and vanadium-based compounds. Hitherto, the most promising anode materials are those carbon-based, such as graphite, soft, or hard carbon, each with its advantages and disadvantages. Although a wide variety of strategies have been reported with excellent results, there is still a need to improve the standardization of the best carbon properties, electrode formulation, and electrolyte composition, given the impossibility of a direct comparison. Therefore, additional effort should be made to understand what are the crucial carbon parameters to develop a reference electrode and electrolyte formulation to further boost their performance and move a step forward in the commercialization of KIBs. Full article
(This article belongs to the Special Issue Advanced Anode Materials for Alkali-Ion Batteries)
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12 pages, 5879 KiB  
Article
Advanced Thermoelectric Performance of SWCNT Films by Mixing Two Types of SWCNTs with Different Structural and Thermoelectric Properties
by Yutaro Okano, Hisatoshi Yamamoto, Koki Hoshino, Shugo Miyake and Masayuki Takashiri
Materials 2025, 18(1), 188; https://doi.org/10.3390/ma18010188 (registering DOI) - 4 Jan 2025
Abstract
Semiconducting single-walled carbon nanotubes (SWCNTs) are significantly attractive for thermoelectric generators (TEGs), which convert thermal energy into electricity via the Seebeck effect. This is because the characteristics of semiconducting SWCNTs are perfectly suited for TEGs as self-contained power sources for sensors on the [...] Read more.
Semiconducting single-walled carbon nanotubes (SWCNTs) are significantly attractive for thermoelectric generators (TEGs), which convert thermal energy into electricity via the Seebeck effect. This is because the characteristics of semiconducting SWCNTs are perfectly suited for TEGs as self-contained power sources for sensors on the Internet of Things (IoT). However, the thermoelectric performances of the SWCNTs should be further improved by using the power sources. The ideal SWCNTs have a high electrical conductivity and Seebeck coefficient while having a low thermal conductivity, but it is challenging to balance everything. In this study, to improve the thermoelectric performance, we combined two types of SWCNTs: one with a high electrical conductivity (Tuball 01RW03, OCSiAl) and the other with a high Seebeck coefficient and low thermal conductivity (ZEONANO SG101, ZEON). The SWCNT inks were prepared by mixing two types of SWCNTs using ultrasonic dispersion while varying the mixing ratios, and p-type SWCNT films were prepared using vacuum filtration. The highest dimensionless figure-of-merit of 1.1 × 10−3 was exhibited at approximately 300 K when the SWCNT film contained the SWCNT 75% of SWCNT (ZEONANO SG101) and 25% of SWCNT (Tuball 01RW03). This simple process will contribute to the prevalent use of SWCNT-TEG as a power source for IoT sensors. Full article
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15 pages, 3362 KiB  
Article
Mechanical and Energy Evolution Characteristics of Fractured Sandstone Materials: A True Triaxial Experimental Study
by Guowen Sun, Yu Lu, Gun Huang, Qinming Liang and Xinyu Huang
Materials 2025, 18(1), 175; https://doi.org/10.3390/ma18010175 - 3 Jan 2025
Viewed by 215
Abstract
To investigate the mechanical and energy evolution characteristics of fractured rock under true triaxial stresses, true triaxial strength compression experiments on fractured sandstone were conducted with varying crack lengths and widths. The results indicate that under true triaxial stresses, the peak stress of [...] Read more.
To investigate the mechanical and energy evolution characteristics of fractured rock under true triaxial stresses, true triaxial strength compression experiments on fractured sandstone were conducted with varying crack lengths and widths. The results indicate that under true triaxial stresses, the peak stress of the rock exhibits a gradual decline with an increase in crack length and width. Meanwhile, crack initiation stress and crack damage stress of fractured sandstone also demonstrate a declining trend overall, and the influence of crack length on the characteristic stress (crack initiation stress and crack damage stress) of sandstone is more pronounced than that of crack width. According to the energy analysis results, the total strain energy of fractured sandstone gradually decreases with an increase in crack length and width. The results offer a theoretical foundation for the strength assessment and stability management of fractured rock materials during deep coal mining operations. Full article
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19 pages, 5506 KiB  
Article
Binder-Less Molybdenum Doped CoO Based Integrated Electrodes Fabricated by Electric Discharge Corrosion for High-Efficiency Supercapacitors
by Ri Chen, Zehan Xu, Yunying Xu, Tujun Lei, Dawei Liu, Chunlong Chen, Wenxia Wang, Igor Zhitomirsky, Muchao Qu and Guoying Zhang
Materials 2025, 18(1), 80; https://doi.org/10.3390/ma18010080 - 27 Dec 2024
Viewed by 366
Abstract
Due to its low cost, natural abundance, non-toxicity, and high theoretical capacitance, cobalt oxide (CoO) stands as a promising candidate electrode material for supercapacitors. In this study, binder-less molybdenum doped CoO (Mo@CoO) integrated electrodes were one-step fabricated using a simple electric discharge corrosion [...] Read more.
Due to its low cost, natural abundance, non-toxicity, and high theoretical capacitance, cobalt oxide (CoO) stands as a promising candidate electrode material for supercapacitors. In this study, binder-less molybdenum doped CoO (Mo@CoO) integrated electrodes were one-step fabricated using a simple electric discharge corrosion (EDC) method. This EDC method enables the direct synthesis of Mo@CoO active materials with oxygen vacancy on cobalt substrates, without any pre-made templates, conductive additives, or chemicals. Most importantly, the EDC method enables precise control over the discharge processing parameter of pulse width, which facilitates tailoring the surface morphologies of the as-prepared Mo@CoO active materials. It was found that the fabricated Mo@CoO based symmetric supercapacitor prepared by a pulse width of 24 μs (Mo@CoO-SCs24) achieved a maximum areal capacitance 36.0 mF cm−2 (0.15 mA cm−2), which is 1.83 and 1.97 times higher than that of Mo@CoO-SCs12 and Mo@CoO-SCs36. Moreover, the Mo@CoO-SCs24 devices could be worked at 10 V s−1, which demonstrates their fast charge/discharge characteristic. These results demonstrated the significant potential of the EDC strategy for efficiency fabricating various metal oxide binder-less integrated electrodes for various applications, like supercapacitors, batteries and sensors. Full article
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17 pages, 3830 KiB  
Article
Corona Poling Enabling Gravure Printing of Electroactive Flexible PVDF-TrFE Devices
by Giuliano Sico, Maria Montanino, Fausta Loffredo, Carmela Borriello and Riccardo Miscioscia
Materials 2025, 18(1), 22; https://doi.org/10.3390/ma18010022 - 25 Dec 2024
Viewed by 386
Abstract
Polyvinylidene fluoride (PVDF)-based materials are the most researched polymers in the field of energy harvesting. Their production in thin-film form through printing technologies can potentially offer several manufacturing and performance advantages, such as low-cost, low-temperature processing, use of flexible substrates, custom design, low [...] Read more.
Polyvinylidene fluoride (PVDF)-based materials are the most researched polymers in the field of energy harvesting. Their production in thin-film form through printing technologies can potentially offer several manufacturing and performance advantages, such as low-cost, low-temperature processing, use of flexible substrates, custom design, low thermal inertia and surface-scaling performance. However, solution-based processes, like printing, miss fine control of the microstructure during film-forming, making it difficult to achieve a high level of polarization, necessary for PVDF to exhibit electroactive characteristics. Here, corona treatment is investigated for the poling of gravure-printed polyvinylidene fluoride–trifluoroethylene (PVDF-TrFE) films, as a particularly suitable poling method for printing since it is rapid, contactless and scalable, and no metal electrodes are required. Effects of corona conditioning on the functional properties of the printed films were examined and discussed. Electroactive properties of corona-poled printed films improved manyfold when they were treated at 9 kV, near room temperature (30 °C) and using very short treatment time (30 s). In particular, piezoelectric and pyroelectric coefficients improved tenfold and by two orders of magnitude, respectively. Considering the upscaling potential of roll-to-roll gravure printing and corona poling, combined with the area-scaling performance of thin-film-based generators, our results can enable the corona-printing process for mass production of future electroactive flexible PVDF-based devices. Full article
(This article belongs to the Section Energy Materials)
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15 pages, 5908 KiB  
Article
Fabrication and Coating of Porous Ti6Al4V Structures for Application in PEM Fuel Cell and Electrolyzer Technologies
by Juan Villemur, Carlos Romero, Jose Manuel Crego and Elena Gordo
Materials 2024, 17(24), 6253; https://doi.org/10.3390/ma17246253 - 21 Dec 2024
Viewed by 461
Abstract
The production of green hydrogen through proton exchange membrane water electrolysis (PEMWE) is a promising technology for industry decarbonization, outperforming alkaline water electrolysis (AWE). However, PEMWE requires significant investment, which can be mitigated through material and design advancements. Components like bipolar porous plates [...] Read more.
The production of green hydrogen through proton exchange membrane water electrolysis (PEMWE) is a promising technology for industry decarbonization, outperforming alkaline water electrolysis (AWE). However, PEMWE requires significant investment, which can be mitigated through material and design advancements. Components like bipolar porous plates (BPPs) and porous transport films (PTFs) contribute substantially to costs and performance. BPPs necessitate properties like corrosion resistance, electrical conductivity, and mechanical integrity. Titanium, commonly used for BPPs, forms a passivating oxide layer, reducing efficiency. Effective coatings are crucial to address this issue, requiring conductivity and improved corrosion resistance. In this study, porous Ti64 structures were fabricated via powder technology, treating them with thermochemical nitriding. The resulting structures with controlled porosity exhibited enhanced corrosion resistance and electrical conductivity. Analysis through scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), grazing incidence XRD and X-ray photoelectron spectroscopy (XPS) confirmed the effectiveness of the coating, meeting performance requirements for BPPs. Full article
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13 pages, 8753 KiB  
Article
Effect of TiO2 Coating on Structure and Electrochemical Performance of LiNi0.6Co0.2Mn0.2O2 Cathode Material for Lithium-Ion Batteries
by Lin Li, Zhongyu Li, Zhifan Kuang, Hao Zheng, Minjian Yang, Jianwen Liu, Shiquan Wang and Hongying Liu
Materials 2024, 17(24), 6222; https://doi.org/10.3390/ma17246222 - 19 Dec 2024
Viewed by 358
Abstract
High-nickel ternary LiNi0.6Co0.2Mn0.2O2 (NCM622) is a promising cathode material for lithium-ion batteries due to its high discharge-specific capacity and energy density. However, problems of NCM622 materials, such as unstable surface structure, lithium–nickel co-segregation, and intergranular cracking, [...] Read more.
High-nickel ternary LiNi0.6Co0.2Mn0.2O2 (NCM622) is a promising cathode material for lithium-ion batteries due to its high discharge-specific capacity and energy density. However, problems of NCM622 materials, such as unstable surface structure, lithium–nickel co-segregation, and intergranular cracking, led to a decrease in the cycling performance of the material and an inability to fully utilize high specific capacity. Surface coating was the primary approach to address these problems. The effect of TiO2 coating prepared by the sol–gel method on the performance of LiNi0.6Co0.2Mn0.2O2 was studied, mainly including the morphology, cell structure, and electrochemical properties. LiNi0.6Co0.2Mn0.2O2 was coated by TiO2 with a thickness of about 5 nm. Compared with the pristine NCM622 electrode, the electrochemical performance of the TiO2-coated NCM622 electrodes is improved. Among all TiO2-coated NCM622, the NCM622 cathode with TiO2 coating content of 0.5% demonstrates the highest capacity retention of 89.3% and a discharge capacity of 163.9 mAh g−1, in contrast to 80.9% and145 mAh g−1 for the pristine NCM622 electrode, after 100 cycles at 0.3 C between 3 and 4.3 V. The cycle life of the 5 wt% TiO2-coated NCM622 electrode is significantly improved at a high cutoff voltage of 4.6 V. The significantly enhanced cycling performance of TiO2-coated NCM622 materials could be attributed to the TiO2 coating layer that could block the contact between the material surface and the electrolyte, reducing the interface side reaction and inhibiting the transition metal dissolution. At the same time, the coating layer maintained the stability of layered structures, thus reducing the polarization phenomenon of the electrode and alleviating the irreversible capacity loss in the cycle process. Full article
(This article belongs to the Special Issue Catalytic Materials and Renewable Chemistry for Energy and Fuels)
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20 pages, 5343 KiB  
Article
Synthesis, Purification, and Characterization of Molten Salt Fuel for the SALIENT-03 Irradiation Experiment
by Pavel Souček, Ondřej Beneš, Pieter Ralph Hania, Konstantin Georg Kottrup, Elio D’Agata, Alcide Rodrigues, Helena Johanna Uitslag-Doolaard and Rudy J. M. Konings
Materials 2024, 17(24), 6215; https://doi.org/10.3390/ma17246215 - 19 Dec 2024
Viewed by 359
Abstract
This work presents the synthesis, purification, and characterization of a molten salt fuel for the irradiation experiment SALIENT-03 (SALt Irradiation ExperimeNT), a collaborative effort between the Nuclear Research and Consultancy Group and the Joint Research Centre, European Commission. The primary objective of the [...] Read more.
This work presents the synthesis, purification, and characterization of a molten salt fuel for the irradiation experiment SALIENT-03 (SALt Irradiation ExperimeNT), a collaborative effort between the Nuclear Research and Consultancy Group and the Joint Research Centre, European Commission. The primary objective of the project is to investigate the corrosion behavior of selected Ni-alloy based structural materials which are being considered for the construction of fluoride molten salt reactors. During the test, these materials will be exposed to selected liquid molten fuel salts under irradiation in the High Flux Reactor in Petten, the Netherlands. In addition, the properties and distribution of the fission products formed in the fuel salt during burn-up will be studied by various post irradiation examinations. In the SALIENT-03 fuel, U and Pu fluorides, as fissile material, are dissolved in a carrier melt based on a 787LiF-22ThF4 eutectic mixture to form fuel salts with four different compositions, containing PuF3, UF4, UF3, and CrF3. This article comprehensively describes all the steps of this fuel synthesis process: the synthesis of the required pure fluoride powders (7LiF, ThF4, UF4, UF3, and PuF3); the mixing, melting, and purification of the different fuel salt compositions; and the fabrication of solid ingots to be loaded into the irradiation capsules. The characterization of the intermediate and final products is also carried out, following a rigorous quality assurance protocol. The quality assurance is achieved using an analytical scheme consisting of mass balance-based conversion efficiency evaluation, X-ray diffraction, and differential scanning calorimetry analyses. All experimental goals were successfully achieved, highlighting promising prospects for advancing future research and development regarding fuel production methods for fluoride-based molten salt reactors. Full article
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18 pages, 2363 KiB  
Article
Mixed Pt-Ni Halide Perovskites for Photovoltaic Application
by Huilong Liu, Rubaiya Murshed and Shubhra Bansal
Materials 2024, 17(24), 6196; https://doi.org/10.3390/ma17246196 - 18 Dec 2024
Viewed by 317
Abstract
Cs2PtI6 is a promising photoabsorber with a direct bandgap of 1.4 eV and a high carrier lifetime; however, the cost of Pt inhibits its commercial viability. Here, we performed a cost analysis and experimentally explored the effect of replacing Pt [...] Read more.
Cs2PtI6 is a promising photoabsorber with a direct bandgap of 1.4 eV and a high carrier lifetime; however, the cost of Pt inhibits its commercial viability. Here, we performed a cost analysis and experimentally explored the effect of replacing Pt with earth-abundant Ni in solution-processed Cs(PtxNi1−x)(I,Cl)3 thin films on the properties and stability of the perovskite material. Films fabricated with CsI and PtI2 precursors result in a perovskite phase with a bandgap of 2.13 eV which transitions into stable Cs2PtI6 with a bandgap of 1.6 eV upon annealing. The complete substitution of PtI2 in films with CsI + NiCl2 precursors results in a wider bandgap of 2.35 eV and SEM shows two phases—a rod-like structure identified as CsNi(I,Cl)3 and residual white particles of CsI, also confirmed by XRD and Raman spectra. Upon extended thermal annealing, the bandgap reduces to 1.65 eV and transforms to CsNiCl3 with a peak shift to higher 2-theta. The partial substitution of PtI2 with NiCl2 in mixed 50-50 Pt-Ni-based films produces a bandgap of 1.9 eV, exhibiting a phase of Cs(Pt,Ni)(I,Cl)3 composition. A similar bandgap of 1.85 eV and the same diffraction pattern with improved crystallinity is observed after 100 h of annealing, confirming the formation of a stable mixed Pt-Ni phase. Full article
(This article belongs to the Special Issue Advanced Energy Materials for Perovskite Solar Cells)
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21 pages, 4985 KiB  
Article
DSSCs Sensitized with Phenothiazine Derivatives Containing 1H-Tetrazole-5-acrylic Acid as an Anchoring Unit
by Muhammad Faisal Amin, Paweł Gnida, Jan Grzegorz Małecki, Sonia Kotowicz and Ewa Schab-Balcerzak
Materials 2024, 17(24), 6116; https://doi.org/10.3390/ma17246116 - 14 Dec 2024
Viewed by 409
Abstract
Phenothiazine-based photosensitizers bear the intrinsic potential to substitute various expensive organometallic dyes owing to the strong electron-donating nature of the former. If coupled with a strong acceptor unit and the length of N-alkyl chain is appropriately chosen, they can easily produce high efficiency [...] Read more.
Phenothiazine-based photosensitizers bear the intrinsic potential to substitute various expensive organometallic dyes owing to the strong electron-donating nature of the former. If coupled with a strong acceptor unit and the length of N-alkyl chain is appropriately chosen, they can easily produce high efficiency levels in dye-sensitized solar cells. Here, three novel D-A dyes containing 1H-tetrazole-5-acrylic acid as an acceptor were synthesized by varying the N-alkyl chain length at its phenothiazine core and were exploited in dye-sensitized solar cells. Differential scanning calorimetry showed that the synthesized phenothiazine derivatives exhibited behavior characteristic of molecular glasses, with glass transition and melting temperatures in the range of 42–91 and 165–198 °C, respectively. Based on cyclic and differential pulse voltammetry measurements, it was evident that their lowest unoccupied molecular orbital (LUMO) (−3.01–−3.14 eV) and highest occupied molecular orbital (HOMO) (−5.28–−5.33 eV) values were fitted to the TiO2 conduction band and the redox energy of I/I3 in electrolyte, respectively. The experimental results were supported by density functional theory, which was also utilized for estimation of the adsorption energy of the dyes on the TiO2 and its size. Finally, the compounds were tested in dye-sensitized solar cells, which were characterized based on current–voltage measurements. Additionally, for the compound giving the best photovoltaic response, the efficiency of the DSSCs was optimized by a photoanode modification involving the use of cosensitization and coadsorption approaches and the introduction of a blocking layer. Subsequently, two types of tandem dye-sensitized solar cells were constructed, which resulted in an increase in photovoltaic efficiency to 6.37%, as compared to DSSCs before modifications, with a power conversion value of 2.50%. Full article
(This article belongs to the Special Issue Advances in Solar Cell Materials and Structures—Second Edition)
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8 pages, 6337 KiB  
Communication
Improving the Antioxidant Properties of Tin-Based Perovskite for the Enhanced Performance of Near-Infrared Light-Emitting Diodes Through the Synergy of Sn and SnF2
by Yipeng Shen, Jianan Chen, Yuhan Si, Zhengguo Xiao, Kai Kang, Zhaobing Tang, Jing Wang and Chaoyu Xiang
Materials 2024, 17(24), 6059; https://doi.org/10.3390/ma17246059 - 11 Dec 2024
Viewed by 408
Abstract
Tin-based perovskite has emerged as an excellent luminescent material due to its non-toxicity and narrow bandgap compared to lead-based perovskite. However, its tin ions are easily oxidized by oxygen, which leads to increased vacancy defects and poor crystallinity, presenting a significant challenge in [...] Read more.
Tin-based perovskite has emerged as an excellent luminescent material due to its non-toxicity and narrow bandgap compared to lead-based perovskite. However, its tin ions are easily oxidized by oxygen, which leads to increased vacancy defects and poor crystallinity, presenting a significant challenge in obtaining high-quality perovskite films. In this context, we introduced an approach by synergistically adding SnF2 and tin powder into the precursor solution to enhance the antioxidation of Sn ions. This method effectively improved the crystallinity of the perovskite films, reduced the density of defect states, and enhanced the photoluminescence performance of the films. Based on these findings, we successfully fabricated tin-based near-infrared perovskite light-emitting diodes (PeLEDs). With a 20% improvement in the Sn2+ content in the film, we achieved a threefold increase in the external quantum efficiency of the devices, reaching 3.6%. Full article
(This article belongs to the Special Issue Advances in Perovskite Oxide Optoelectronic Functional Materials)
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14 pages, 2016 KiB  
Article
Transition Boundary from Laminar to Turbulent Flow of Microencapsulated Phase Change Material Slurry—Experimental Results
by Krzysztof Dutkowski, Marcin Kruzel and Martyna Kochanowska
Materials 2024, 17(24), 6041; https://doi.org/10.3390/ma17246041 - 10 Dec 2024
Viewed by 441
Abstract
An ice slurry or an emulsion of a phase change material (PCM) is a multiphase working fluid from the so-called Latent Functional Thermal Fluid (LFTF) group. LFTF is a fluid that uses, in addition to specific heat, the specific enthalpy of the phase [...] Read more.
An ice slurry or an emulsion of a phase change material (PCM) is a multiphase working fluid from the so-called Latent Functional Thermal Fluid (LFTF) group. LFTF is a fluid that uses, in addition to specific heat, the specific enthalpy of the phase change of its components to transfer heat. Another fluid type has joined the LFTF group: a slurry of encapsulated phase change material (PCM). Technological progress has made it possible for the phase change material to be enclosed in a capsule of the size of the order of micrometers (microencapsulated PCM—mPCM) or nanometers (nanoencapsulated PCM—nPCM). This paper describes a method for determining the Reynolds number (Re) at which the nature of the flow of the mPCM slurry inside a straight pipe changes. In addition, the study results of the effect of the concentration of mPCM in the slurry and the state of the PCM inside the microcapsule on the value of the critical Reynolds number (Recr) are presented. The aqueous slurry of mPCM with a concentration from 4.30% to 17.20% wt. flowed through a channel with an internal diameter of d = 4 mm with a flow rate of up to 110 kg/h (Re = 11,250). The main peak melting temperature of the microencapsulated paraffin wax used in the experiments was around 24 °C. The slurry temperature during the tests was maintained at a constant level. It was 7 °C, 24 °C and 44 °C (the PCM in the microcapsule was, respectively, a solid, underwent a phase change and was a liquid). The experimental studies clearly show that the concentration of microcapsules in the slurry and the state of the PCM in the microcapsule affect the critical Reynolds number. The higher the concentration of microcapsules in the slurry, the more difficult it was to maintain laminar fluid flow inside the channel. Furthermore, the laminar flow of the slurry terminated at a lower critical Reynolds number when the PCM in the microcapsule was solid. Caution is advised when choosing the relationship to calculate the flow resistance or heat transfer coefficients, because assuming that the flow motion changes at Re = 2300, as in the case of pure liquids, may be an incorrect assumption. Full article
(This article belongs to the Special Issue Smart Materials and Devices in Heat and Mass Transfer)
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15 pages, 2348 KiB  
Article
Fine Tuning the Glass Transition Temperature and Crystallinity by Varying the Thiophene-Quinoxaline Copolymer Composition
by Xun Pan and Mats R. Andersson
Materials 2024, 17(24), 6031; https://doi.org/10.3390/ma17246031 - 10 Dec 2024
Viewed by 447
Abstract
In recent years, the design and synthesis of high-performing conjugated materials for the application in organic photovoltaics (OPVs) have achieved lab-scale devices with high power conversion efficiency. However, most of the high-performing materials are still synthesised using complex multistep procedures, resulting in high [...] Read more.
In recent years, the design and synthesis of high-performing conjugated materials for the application in organic photovoltaics (OPVs) have achieved lab-scale devices with high power conversion efficiency. However, most of the high-performing materials are still synthesised using complex multistep procedures, resulting in high cost. For the upscaling of OPVs, it is also important to focus on conjugated polymers that can be made via fewer simple synthetic steps. Therefore, an easily synthesised amorphous thiophene−quinoxaline donor polymer, TQ1, has attracted our attention. An analogue, TQ-EH that has the same polymer backbone as TQ1 but with short branched side-chains, was previously reported as a donor polymer with increased crystallinity. We have synthesised copolymers with varied ratios between octyloxy and branched (2-ethylhexyl)oxy-substituted quinoxaline units having the same polymer backbone, with the aim to control the aggregation/crystallisation behaviour of the resulting copolymers. The optical properties, glass transition temperatures and degree of crystallinity of the new copolymers were systematically examined in relation to their copolymer composition, revealing that the composition can be used to fine-tune these properties of conjugated polymers. In addition, multiple sub-Tg transitions were found from some of the polymers, which are not commonly or clearly seen in other conjugated polymers. The new copolymers were tested in photovoltaic devices with a fullerene derivative as the acceptor, achieving slightly higher performances compared to the homopolymers. This work demonstrates that side-chain modification by copolymerisation can fine-tune the properties of conjugated polymers without requiring complex organic synthesis, thereby expanding the number of easily synthesised polymers for future upscaling of OPVs. Full article
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26 pages, 3118 KiB  
Article
Assessment of the Influence of the Life Cycle of Solar Power Plant Materials and Components on Ecosystem Quality
by Patryk Leda, Grzegorz Szala and Izabela Piasecka
Materials 2024, 17(24), 6028; https://doi.org/10.3390/ma17246028 - 10 Dec 2024
Viewed by 541
Abstract
Currently, silicon is the most often utilized material for photovoltaic cell manufacturing, as it has the potential to convert solar energy directly into electricity. The silicon used in photovoltaic solutions must be highly pure. Large amounts of power, raw materials, and fossil fuels [...] Read more.
Currently, silicon is the most often utilized material for photovoltaic cell manufacturing, as it has the potential to convert solar energy directly into electricity. The silicon used in photovoltaic solutions must be highly pure. Large amounts of power, raw materials, and fossil fuels are consumed in the production process. Post-consumer treatment of polymers, materials, and components also requires energy and matter. These processes have a significant influence on the environment. As a result, the primary purpose of this article is to evaluate the influence of a photovoltaic power plant’s material and component life cycle on ecosystem quality. The research focuses on an actual photovoltaic power plant with a capacity of 2 MW located in northern Poland. According to the findings, photovoltaic modules are the part that has the most negative environmental impact, since their manufacturing requires a substantial amount of materials and energy (primarily from conventional sources). Post-consumer management, in the form of recycling after use, would provide major environmental advantages and reduce detrimental environmental consequences throughout the course of the solar power plant’s full life cycle. Full article
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12 pages, 5804 KiB  
Article
VN Quantum Dots Anchored onto Carbon Nanofibers as a Superior Anode for Sodium Ion Storage
by Xiaoyu Wu, Haimin Zhang, Jiachen Yanghe and Sainan Liu
Materials 2024, 17(23), 6004; https://doi.org/10.3390/ma17236004 - 7 Dec 2024
Viewed by 497
Abstract
Vanadium-based compounds exhibit a high theoretical capacity to be used as anode materials in sodium-ion batteries, but the volume change in the active ions during the process of release leads to structural instability during the cycle. The structure of carbon nanofibers is stable, [...] Read more.
Vanadium-based compounds exhibit a high theoretical capacity to be used as anode materials in sodium-ion batteries, but the volume change in the active ions during the process of release leads to structural instability during the cycle. The structure of carbon nanofibers is stable, while it is difficult to deform. At the same time, the huge specific surface area energy of quantum dot materials can speed up the electrochemical reaction rate. Here, we coupled quantum-grade VN nanodots with carbon nanofibers. The strong coupling of VN quantum dots and carbon nanofibers makes the material have a network structure of interwoven nanofibers. Secondly, the carbon skeleton provides a three-dimensional channel for the rapid migration of sodium ions, and the material has low charge transfer resistance, which promotes the diffusion, intercalation and release of sodium ions, and significantly improves the electrochemical activity of sodium storage. When the material is used as the anode material in sodium ion batteries, the specific capacity is stable at 230.3 mAh g−1 after 500 cycles at 0.5 A g−1, and the specific capacity is still maintained at 154.7 mAh g−1 after 1000 cycles at 2 A g−1. Full article
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