Search Results (2,842)

Chlorophyll, a natural photosynthetic pigment, is gaining interest for its sustainable and eco-friendly applications in renewable energy, particularly as a photosensitizer in dye-sensitized solar cells (DSSCs). This study investigates the feasibility of chlorophyll extracted from Moringa oleifera as a natural photosensitizer in DSSCs, building on our previous work demonstrating its high chlorophyll content and long-term stability. Chlorophyll was extracted using acetone under optimal conditions (45 °C, 60 min) and applied in DSSCs comprising a TiO₂ photoanode, iodide/triiodide electrolyte, and platinum counter electrode. The TiO₂ photoanode was characterised using UV-Vis spectroscopy, FE-SEM, XRD, and Raman spectroscopy, confirming the presence of pure anatase phase TiO₂ with uniform spherical nanoparticle morphology. The fabricated DSSCs achieved a short-circuit current density of 0.197 mA cm⁻², an open-circuit voltage of 0.44 V, a fill factor of 32%, and a photoconversion efficiency (PCE) of 0.027%. While this performance is lower than the highest reported chlorophyll-based DSSC efficiency (4.6%), the results demonstrate that M. oleifera is a viable and sustainable source of chlorophyll for DSSC applications. The findings highlight the importance of dye–semiconductor interactions and suggest that further optimisation through co-sensitization, TiO₂ surface modification, and improved dye anchoring could enhance device performance. Full article

Copper complexes have recently emerged as key materials for advancing dye-sensitized solar cells (DSSCs) toward more sustainable and high-performance photovoltaic technologies. This minireview summarizes the most significant achievements reported from 2024 onwards, highlighting the multifaceted role of copper in DSSCs as sensitizers, redox mediators, and functional components in innovative device architectures. Significant progress has been achieved in all these roles; however, the most remarkable advances concern copper-based redox mediators, where fine-tuning of ligand environments, additives, and electrolyte formulations has enabled excellent efficiencies, exceeding 10%, together with outstanding long-term stability. Developments in aqueous and quasi-solid-state systems further enhance the environmental compatibility and durability of these devices. In addition, novel concepts, including retro cells and copper-based “zombie” DSSCs, demonstrate the versatility of copper chemistry in simplifying device design and enabling new applications. Overall, these findings confirm copper complexes as highly promising earth-abundant alternatives to noble-metal-based systems although further work is still required to optimize light absorption, suppress charge recombination, and improve large-scale device stability. Full article

In this study, an ecofriendly microfluidic microbial biocathode electrolysis cell is developed for hydrogen production. Low-cost microbial catalysts are employed on single-walled carbon nanotube cathodes instead of noble metal (platinum) catalysts. The channel layer for the electrolyte flow is fabricated from polydimethylsiloxane and coated with Parylene C to minimize oxygen permeability. A miniaturized electrolysis cell is constructed by depositing electrodes onto a glass substrate and bonding them to a polydimethylsiloxane channel layer via plasma surface treatment. The establishment of the biocathode during the start-up procedure is analyzed, and the hydrogen production performance of the biocathode microbial electrolysis cell (MEC) is evaluated under various applied voltages and electrolyte flow rates. At higher applied voltages and optimal flow rates, biofilm formation is well-developed, resulting in a peak hydrogen production rate of 14.8 m³ H₂ m⁻³ d⁻¹. The developed MEC biocathode demonstrates significant performance, achieving a current density of 0.22 A m⁻², corresponding to 69% of that of a platinum-catalyzed cathode MEC, while exhibiting a substantially longer operating duration of 12 h. These results demonstrate the potential to overcome the inherent limitations of biocathodes, thereby addressing the high cost and low durability of conventional platinum-catalyzed MECs. Compared with conventional MEC systems, the proposed microfluidic configuration enables membraneless operation with reduced internal resistance and rapid biofilm formation, demonstrating its potential as a compact and cost-effective platform for biohydrogen production. Full article

The accuracy of lithium-ion battery thermal-runaway early warning is strongly affected by the State of Charge (SOC). To improve the adaptability of fixed-threshold strategies, this study investigated SOC-dependent temperature and gas responses of 18650 LiNi₁/₃Co₁/₃Mn₁/₃O₂/graphite cells under thermal abuse at 50%, 75%, and 100% SOC, representing limited and complete thermal-runaway scenarios respectively, using a sealed pressure-resistant chamber. Temperature and chamber concentrations of characteristic gases, including CO₂, CO, C₂H₄, and CH₄, were monitored. The results show that higher SOC lowers the critical temperature for rapid self-heating, advances characteristic gas appearance, and increases the measured chamber gas concentrations by approximately 2.1–2.8 orders of magnitude. Reaction-kinetics analysis indicates that stronger electrolyte reduction by highly lithiated graphite at high SOC is the main reason for the different gas-evolution patterns. Based on these findings, an SOC-adaptive dual-parameter threshold model combining temperature and CO₂ concentration was established and retrospectively evaluated. The model provides earlier and more balanced warnings than fixed-threshold strategies, while the limitations associated with discrete GC-MS sampling and practical BMS implementation are discussed. Full article

Lithium metal batteries are considered one of the most promising technological routes for next-generation energy storage systems with high energy density. However, when paired with high-voltage cathodes such as NCM811, conventional lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-based electrolytes face severe corrosion of the aluminum current collector when the operating voltage exceeds 3.8 V vs. Li⁺/Li, leading to rapid capacity decay and even cell failure. In this work, we designed and synthesized a cyano-containing lithium salt, lithium cyano(trifluoromethanesulfonyl)imide (LiCTFSI), to address this issue. The electrochemical performance of 1 M LiCTFSI and 1 M LiTFSI in the same carbonate solvent was systematically compared in NCM811/Li cells. The results demonstrate that LiCTFSI effectively suppresses aluminum corrosion at high potentials and forms a thinner and more compact cathode electrolyte interphase to protect NCM811 cathodes. With the LiCTFSI electrolyte, NCM811/Li cells (mass loading = 19.55 mg cm⁻²) achieve a capacity retention of 81.7% after 200 cycles at a high cutoff voltage of 4.6 V vs. Li⁺/Li. This work provides a new strategy for developing advanced electrolyte salts for high-voltage, high-energy-density lithium metal batteries. Full article

Lithium metal batteries (LMBs) incorporating solid-state electrolytes (SSEs) promise high energy density and safety, yet their practical deployment is hindered by poor interfacial stability between SSEs and lithium metal anodes. Here we show that a simple incorporation of LiBF₄ into the sulfohalide (Li₃SCl) framework forms a mixture Li₃SCl@LiBF₄ (LSC@BF) SSE via a two-step solid-state synthesis, preserving a high room-temperature ionic conductivity of 4.32 × 10⁻⁴ S cm⁻¹ with a low activation energy of 0.22 eV while fundamentally altering the interface. X-ray photoelectron spectroscopy and electron microscopy reveal that LiBF₄ promotes the in situ formation of a mechanically robust, LiF-rich solid-electrolyte interphase at the SSE|Li interface. This LiF-rich layer effectively suppresses lithium dendrite growth and stabilizes the interface, enabling symmetric Li|LSC@BF|Li cells to achieve stable lithium plating/stripping for over 800 h at 0.2 mA cm⁻². Cross-sectional post-mortem imaging confirms a dense, void-free interface without dendrite penetration. Our work demonstrates that LiBF₄ incorporation offers a simple, scalable strategy to simultaneously maintain high ionic conductivity and resolve interfacial instability in sulfohalide SSEs for high-performance LMBs. Full article

Silicon anodes hold great promise in high-energy lithium-ion batteries (LIBs) owing to their ultrahigh theoretical specific capacity, appropriate operating voltage, and low costs. However, the drastic volume expansion, inferior electronic conductivity, and unstable solid electrolyte interphase of Si anodes severely restrict their practical application. Herein, a nest-shaped microporous silicon (NMPSi) is rationally designed via acid–base co-etching and then synergistically regulated by surface thin-film carbon coating and ZIF-67-derived hard carbon nanotemplate (NMPSi@THC) by an in situ liquid-phase coating strategy. The constructed unique architecture is capable of buffering the huge volume expansion of inner NMPSi during cycling and constructing an optimized electron/ion transport network, thereby stabilizing the SEI film and preserving the electrode’s structural integrity. When it is evaluated as a LIB anode, the NMPSi@THC exhibits typically improved initial coulombic efficiency (ICE) and outstanding long-life cyclic stability (622.7 mAh g⁻¹ after 300 cycles at 1 A g⁻¹ and 2 mg cm⁻²). Furthermore, the NMPSi@THC//LiFePO₄ full cell delivers an ultrahigh ICE of 94% and a capacity retention rate of 86%, demonstrating its practical application potential. Compared with most recently reported Si anodes, this report delivers better cycling stability and maintains more intact electrode structure under relatively high current density and areal mass loading in half/full cells after long-term cycling. This research offers a convenient and scalable route to fabricate highly stable microporous Si anodes toward high-energy and long-lifespan LIBs. Full article

In this study, an electrochemical system for methane conversion was developed, employing Ni- and Ce-doped LaCoO₃ perovskite as the anode catalyst in an Na₂CO₃ electrolyte. Structural characterization revealed that the La_1−yCe_yCo_1−xNi_xO₃ (x = 0–0.5, y = 0–0.12) synthesized by the sol–gel method maintains the perovskite structure, but is rich in oxygen vacancies. Electrochemical studies revealed that the performance of methane activation is related to the presence of Ni(III) in the catalyst, and reactive oxygen species (•OH and HOO⁻) are provided through water oxidation reactions (WOR) in the Na₂CO₃ electrolyte. The electrocatalytic performance of the synthesized La_0.92Ce_0.08Co_0.5Ni_0.5O₃ during methane conversion was verified in an electrolysis cell, and ethanol and acetic acid were identified as the methane conversion oxygenates. Under ambient conditions, the formation rate of ethanol reached 577.0 μmol g_cat⁻¹ h⁻¹ at 0.90 V (vs. Ag/AgCl) in 0.5 mol L⁻¹ Na₂CO₃. The catalyst was found to retain structural integrity and sustain catalytic activity over multiple reaction cycles. Full article

Variants in the human PAX4 gene are associated with both monogenic and complex forms of diabetes, yet their pathogenic effects remain difficult to define in models that accurately mimic human islet architecture and neonatal metabolic transitions. Here, we created a porcine PAX4 loss-of-function model using CRISPR/Cas9 cytidine deaminase base editing to introduce a premature stop codon in the PAX4 coding sequence. PAX4 knockout piglets developed severe hyperglycemia within 24 h of birth, followed by rapid postnatal clinical deterioration and uniform death by day 3. Biochemical analysis showed significant diabetic decompensation, including electrolyte imbalances, hyperosmolality, azotemia, dyslipidemia, and metabolic acidosis. Gross and histological examinations revealed notable pancreatic hypoplasia with preservation of exocrine tissue. Single-nucleus RNA sequencing and immunohistochemistry demonstrated an almost complete loss of insulin- and somatostatin-producing β- and δ-cells, respectively, with relative preservation of glucagon-expressing α-cells. Overall, these results establish PAX4 as a crucial factor in pancreatic endocrine development and postnatal glucose regulation in a large-animal model. This platform offers a human-relevant system for studying diabetes-associated PAX4 variants and for testing regenerative and gene-based therapies for insulin-deficient diabetes. Full article

Electrospun sulfonated polyketone (PK) nanofiber membranes were prepared to investigate the sulfonation-time-dependent structure–property relationships of hydrocarbon-based polymer electrolyte membranes for PEMFC (Polymer Electrolyte Membrane Fuel Cell) applications. NaCl addition to the electrospinning solution increased solution conductivity and enabled the formation of uniform PK nanofibers with an average diameter of approximately 270 nm. Subsequent sulfonation introduced sulfonic-acid-related groups into the PK nanofiber framework, and the resulting membrane properties were strongly governed by sulfonation time. Among the tested membranes, PK-NC16 exhibited the highest proton conductivity of 0.107 ± 0.031 S cm⁻¹ and an ion exchange capacity of 2.82 m_eq g⁻¹, exceeding or comparable to those of Nafion 115 under the tested conditions. FTIR-based analysis indicated that the relative sulfonation index increased up to 16 h, whereas extended sulfonation for 24 h generated additional sulfone/sulfonate-related bands, suggesting possible side reactions or structural changes under prolonged acid treatment. The high water uptake of PK-NC16 enhanced proton transport but also revealed a hydration-sensitive polymer network, as reflected by a voltage degradation rate of approximately −590 μV h⁻¹ during a 100 h short-term stability constant-current test. These results demonstrate that sulfonation time is a key parameter controlling the balance among ionic functionality, hydration, mechanical response, proton conductivity, and PEMFC-relevant single-cell performance in electrospun PK nanofiber membranes. Full article

Substantial advances have been made since the 1970s in reducing the environmental impacts of ammonia production. Renewable-driven electrochemical synthesis offers a promising pathway to decarbonize ammonia production. This review examines an integrated route in which hydrogen is generated photoelectrochemically under concentrated solar irradiation and subsequently used in electrochemical ammonia synthesis. Photoelectrochemical cells are fabricated by electrostatically depositing photosensitive particles onto cathodes to enhance light-driven hydrogen production. Hydrogen production rates and ammonia yield depend strongly on temperature and electrolyte composition. The synthesized hydrogen is fed into a molten salt electrochemical reactor that operates at atmospheric pressure and receives nitrogen from a dedicated supply. This combined solar–electrochemical approach can produce low-carbon ammonia with improved safety and reduced environmental impact, offering a scalable alternative to conventional processes. Full article

Halide solid electrolytes (HSE) have shown remarkable stability against high-voltage cathodes. Some HSE, such as Li₃InCl₆ (LIC), can be readily synthesized via aqueous routes. Here, we expand the aqueous synthesis of LIC to include Y substitution, which has different hydration coordination strengths, to form Li₃In_xY_1−xCl₆ (LIYC, 0 ≤ x ≤1). This composition is intended to combine the high ionic conductivity of LIC with the superior stability of Li₃YCl₆ (LYC). We compared solution-synthesized products with those derived mechanochemically. We found that adding ammonium chloride in a 3:1 ratio to YCl₃ + InCl₃ produces a phase-pure product, with X-ray diffraction (XRD) revealing structure similarity for both routes. Through nuclear magnetic resonance (NMR) and impedance measurements, we evaluate how the synthesis method affects ionic transport, particularly regarding correlated motion. Despite lower initial grain boundary impedance in mechanochemical samples, full cells made from solution-synthesized samples show superior cycling performance. This work establishes a scalable aqueous synthesis route for LIYC that achieves properties comparable to traditional mechanochemical methods. Full article

This study presents the first comprehensive machine learning framework for predicting the performance of an air-breathing polymer electrolyte membrane fuel cell, based on high-fidelity multiphysics data and validated under realistic conditions. Using data generated from a validated multiphysics model, four machine learning models are trained: MLR, RFR, ANN, and SVR. The models aim to capture the effects of geometric, material, and operating parameters on cell performance to support the development of more efficient and sustainable clean energy systems. Evaluation with standard error metrics shows that MLR exhibits large deviations from actual values, highlighting the limitations of linear models and underscoring the need for more complex approaches. ANN and SVR provide high predictive accuracy and generalize well to unseen data, while RFR tends to overfit. Robustness analysis using white Gaussian noise and four-fold cross-validation further confirms the reliability of top-performing models. ANN and SVR models generate polarization curves 4000 and 40,000 times faster, respectively, than the multiphysics model, enabling real-time applications. Both models achieved excellent predictive performance, with R² values exceeding 0.999 under normal operating conditions and remaining above 0.98 even in the presence of noisy inputs. Full article

In order to optimize the sealing structure of the electrolytic cell for hydrogen production by electrolysis of water and enhance its sealing performance, a finite element model of the electrolytic cell sealing was established using software. The influence of different parameters of the sealing rib structure on the sealing performance was studied, and the variation law of gasket compressive stress under different sealing rib slot widths, angles, and spacings was explored. The results show that under the material constants of C10 = 7.0 × 10⁻³ and C01 = 6.05 in the Mooney–Rivlin constitutive model of the gasket, the gasket will deform and embed into the sealing rib groove after compression. At the same time, two parts of stress concentration will occur at the contact area between the gasket and the sealing rib groove, namely tensile stress concentration and compressive stress concentration. This stress concentration is the main source of sealing effect in practical work. After adding the sealing rib groove, the contact area between the sealing rib area and the gasket increases. When maximizing the peak sealing compressive stress serves as the optimization criterion, the optimal pitch settles at 0.4 mm; if the optimization objective shifts to attaining the utmost contact area, the preferable spacing amounts to 1 mm, accompanied by a maximum contact area increment of 34.31 percent. After comprehensive deliberation over sealing stress magnitude, functional sealing area, gas tightness efficiency as well as practical engineering applicability, 0.8 mm is pinpointed in this dissertation as the globally optimal spacing dimension. With a sealing rib pitch of 0.8 mm, a breadth of 1 mm, and an inclined angle of 20 degrees, the gasket yields substantial sealing stress alongside optimized post-assembly sealing contact area, wherein 26.44 percent of the overall gasket area contributes to effective sealing performance. Full article

Ionic liquid-based localized high-concentration electrolytes, leveraging their intrinsically nonflammable safety characteristics and wide electrochemical windows, have emerged as strong contenders for next-generation lithium metal battery electrolytes. However, because such systems are anion-rich, the electrolyte bulk phase tends to form solvation structures dominated by bulky anionic clusters along with an excess of free anions, which triggers persistent and uncontrollable anion decomposition at the interphase. To address this issue, we adopt a strategy of constructing a compressed solvation structure by introducing a weakly interacting chlorinated diluent (TeCA), which helps form a compact solvation environment and alleviates excessive anion decomposition at electrode interphases. In this work, 1,1,2,2-tetrachloroethyl acetate (TeCA) was introduced as a weakly coordinating chlorinated diluent into an ionic-liquid localized high-concentration electrolyte (LHCE) to regulate the Li⁺-FSI⁻ solvation environment. By combining Raman spectroscopy, molecular dynamics simulations, and electrochemical characterization, the TeCA-LHCE system was found to exhibit altered ion-cluster configurations, improved oxidation tolerance, and enhanced interfacial stability under high-voltage conditions. The as-prepared TeCA-LHCE electrolyte presents improved electrochemical performance in comparison with TTE-LHCE and the baseline electrolyte (BE). The Li||Cu half-cell employing TeCA-LHCE achieved a high Coulombic efficiency above 99% over 500 cycles and formed a uniform and dense lithium deposition layer without obvious dendritic growth. When paired with a high-loading NCM811 cathode (10 mg cm⁻²), the TeCA-LHCE-based Li||NCM811 full cell delivered significantly improved cycling stability and rate capability under a high cutoff voltage of 4.3 V. Full article