Search Results (1,832)

The advancement of efficient energy conversion and storage technologies is fundamentally linked to the development of electrochemical systems, including fuel cells, batteries, and electrolyzers, whose performance depends on key electrocatalytic reactions: hydrogen evolution (HER), oxygen evolution (OER), oxygen reduction (ORR), carbon dioxide reduction (CO₂RR), and nitrogen reduction (NRR). Beyond catalyst design, the electrolyte microenvironment significantly influences these reactions by modulating charge transfer, intermediate stabilization, and mass transport, making electrolyte engineering a powerful tool for enhancing performance. This review provides a comprehensive analysis of how fundamental electrolyte properties, including pH, ionic strength, ion identity, and solvent structure, affect the mechanisms and kinetics of these five reactions. We examine in detail how the electrolyte composition and individual ion contributions impact reaction pathways, catalytic activity, and product selectivity. For HER and OER, we discuss the interplay between acidic and alkaline environments, the effects of specific ions, interfacial electric fields, and catalyst stability. In ORR, we highlight pH-dependent activity, selectivity, and the roles of cations and anions in steering 2e⁻ versus 4e⁻ pathways. The CO₂RR and NRR sections explore how the electrolyte composition, local pH, buffering capacity, and proton sources influence activity and the product distribution. We also address challenges in electrolyte optimization, such as managing competing reactions and maximizing Faradaic efficiency. By comparing the electrolyte’s effects across these reactions, this review identifies general trends and design guidelines for enhancing electrocatalytic performance and outlines key open questions and future research directions relevant to practical energy technologies. Full article

All-solid-state lithium batteries (ASSLBs) are emerging as a promising alternative to conventional lithium-ion batteries, offering solutions to challenges related to energy density and safety. Their core advancement relies on breakthroughs in solid-state electrolytes (SEs). SEs can be broadly grouped into two main types: inorganic solid electrolytes (ISEs) and organic solid electrolytes (OSEs). ISEs offer high ionic conductivity (0.1~1 mS cm⁻¹), a lithium-ion transference number close to 1, and excellent thermal stability, but their intrinsic brittleness leads to poor interfacial wettability and processing difficulties, limiting practical applications. In contrast, OSEs exhibit good flexibility and interfacial compatibility but suffer from poor ionic conductivity (10⁻⁴~10⁻² mS cm⁻¹) due to high crystallinity at room temperature, in addition to poor thermal stability and weak mechanical integrity, making it difficult to match high-voltage cathodes and suppress lithium dendrite growth. Against this backdrop, the stability of the organic–inorganic interface plays a crucial role. However, challenges such as low overall conductivity and unstable interfaces still limit their performance. This review provides a microscopic perspective on lithium-ion transport pathways across the polymer phase, the inorganic filler phase, and their interfacial regions. It categorizes inert fillers and active fillers, analyzing their structure–performance relationships and emphasizing the synergistic effects of filler dimensionality, surface chemistry, and interfacial interactions. In addition, cutting-edge analytical methods such as time-of-flight secondary ion mass spectrometry (TOF-SIMS) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) have also been employed and are summarized into their roles for revealing the microstructures and dynamic interfacial behaviors of OICSEs. Finally, future directions are proposed, such as hierarchical pore structure design, surface functionalization, and simulation-guided optimization, aiming to provide theoretical insights and technological strategies for the development of high-performance composite electrolytes for ASSLBs. Full article

The efficient purification of Pb(II)-containing wastewater is essential for safeguarding public health and maintaining the aquatic environment. In this study, novel hydrous ferric oxide (HFO) nanoparticle-embedded poly(vinylidene fluoride) (PVDF) composite adsorption membranes were developed through a simple blending method for efficient Pb(II) removal. This composite membrane (denoted as HFO-PVDF) combines the excellent selectivity of HFO nanoparticles for Pb(II) with the membrane’s advantage of easy scalability. The optimized HFO-PVDF_(1.5) membrane achieved adsorption equilibrium within 20 h and exhibited excellent adsorption capacity. Moreover, adsorption capacity markedly enhanced with increasing temperature, confirming the endothermic nature of the process. The developed HFO-PVDF membranes demonstrate significant potential for real-world wastewater treatment applications, exhibiting exceptional selectivity for Pb(II) in complex ionic matrices and could be effectively regenerated via a relatively straightforward process. Furthermore, filtration and dynamic regeneration tests demonstrated that at an initial Pb(II) concentration of 5 mg/L, the membrane operated continuously for 10–13 h before regeneration, treating up to 200 L/m² of wastewater before breakthrough, highlighting potential for cost-effective industrial wastewater treatment. This study not only demonstrates the high efficiency of the HFO-PVDF membrane for heavy metal ion removal but also provides a theoretical foundation and technical support for its practical application in water treatment. Full article

Over the last few decades, polymer composites have been rapidly making inroads in critical applications of electrical storage devices such as batteries and supercapacitors. Structural supercapacitor composites (SSCs) have emerged as multifunctional materials capable of storing energy while bearing mechanical loads, offering lightweight and compact solutions for energy systems. This study investigates the functionalization of Bisphenol A-based thermosetting polymers with ionic liquids, aiming to synthesize dual-functional structural electrolytes for SSC fabrication. A multifunctional sandwich structure was subsequently fabricated, in which the fabricated SSC served as the core layer, bonded between two structurally robust outer skins. The core layer was fabricated using carbon fibre layers coated with 10% graphene nanoplatelets (GNPs), while the skin layers contained 0.25% GNPs dispersed in the resin matrix. The developed device demonstrated stable operation up to 85 °C, achieving a specific capacitance of 57.28 mFcm⁻² and an energy density of 179 mWhm⁻² at room temperature. The performance doubled at 85 °C, maintaining excellent capacitance retentions across all experimented temperatures. The flexural strength of the developed sandwich SSC at elevated temperature (at 85 °C) was 71 MPa, which exceeds the minimum requirement for roofing sheets as specified in Australian building standard AS 4040.1 (Methods of testing sheet roof and wall cladding, Method 1: Resistance to concentrated loads). Finite element analysis (FEA) was performed using Abaqus CAE to evaluate structural integrity under mechanical loading and predict damage initiation zones under service conditions. The simulation was based on Hashin’s failure criteria and demonstrated reasonable accuracy. This research highlights the potential of multifunctional polymer composite systems in renewable energy infrastructure, offering a robust and energy-efficient material solution aligned with circular economy and sustainability goals. Full article

High-performance batteries for military and extreme environment applications require alternatives to conventional liquid lithium-ion batteries (LIBs), which suffer from poor low-temperature performance and safety risks. All-solid-state lithium batteries (ASSLBs) offer enhanced safety and superior low-temperature capability. In this work, we designed and fabricated composite solid-state electrolytes using polyvinylidene fluoride (PVDF) and polyacrylic acid (PAA) as polymer matrices, N,N-dimethylformamide (DMF) as the solvent, and lithium bis(trifluoromethane sulfonimide) (LiTFSI) as the lithium salt. Composite solutions with varying PAA mass ratios were prepared. Advanced three-dimensional (3D) printing technology enabled the rapid and precise fabrication of electrolyte membranes. An ionic conductivity of about 2.71 × 10⁻⁴ S cm⁻¹ at 25 °C, high mechanical strength, and good thermal properties can be achieved through component and 3D printing process optimization. Assembled LiCoO₂||PVDF@PAA||Li ASSLBs delivered an initial discharge capacity of 165.3 mAh/g at 0.1 mA cm⁻² (room temperature), maintaining 98% capacity retention after 300 cycles. At 0 °C, these cells provided 157.4 mAh/g initial capacity with 85% retention over 100 cycles at 0.1 mA cm⁻². This work identifies the optimal PAA ratio for enhanced electrochemical performance and demonstrates the viability of 3D printing for advanced ASSLB manufacturing. Full article

Lithium–iron disulfide (Li-FeS₂) batteries are plagued by the polysulfide shuttle effect and cathode structural degradation, which significantly hinder their practical application. This study proposes a dual-strategy design that combines a polyacrylonitrile–carbon nanotube (PAN-CNT) composite cathode and a polyvinylidene fluoride (PVDF)-conductive carbon-coated separator to synergistically address these bottlenecks. The PAN-CNT binder establishes chemical anchoring between polyacrylonitrile and FeS₂, enhancing electronic conductivity and mitigating volume expansion. Specifically, the binder boosts the initial discharge capacity by 35% while alleviating the stress-induced pulverization associated with volume changes. Meanwhile, the PVDF-conductive carbon-coated separator enables effective polysulfide trapping via dipole–dipole interactions between PVDF’s polar C-F groups and Li₂S_x species while maintaining unobstructed ion transport with an ionic conductivity of 1.23 × 10⁻³ S cm⁻¹, achieving a Coulombic efficiency of 99.2%. The electrochemical results demonstrate that the dual-modified battery delivers a high initial discharge capacity of 650 mAh g⁻¹ at 0.5 C, with a capacity retention rate of 61.5% after 120 cycles, significantly outperforming the control group’s 47.5% retention rate. Scanning electron microscopy and electrochemical impedance spectroscopy confirm that this synergistic design suppresses polysulfide migration and enhances interfacial stability, reducing the charge transfer resistance from 26 Ω to 11 Ω. By integrating polymer-based functional materials, this work presents a scalable and cost-effective approach for developing high-energy-density Li-FeS₂ batteries, providing a practical pathway to overcome key challenges in their commercialization. Full article

With the continuous expansion of rare earth resource development, the large-scale accumulation of ionic rare earth tailings (IRETs) has exerted pressure on both environmental and resource management. Due to their inherent low reactivity, unstable composition, and potential environmental risks, their widespread engineering application faces many challenges. To achieve the resource utilization of this solid waste, scholars in recent years have conducted extensive research on their application in silicate materials. This study systematically reviews the existing research. Given that the trace rare earth oxides in IRETs exhibit excellent mineralization effects and that IRETs contain a significant amount of clay minerals, IRETs can be feasibly applied in the production of silicate materials, including clinker, tiles, ceramics, glass-ceramics, and geopolymers. The research findings aim to provide technical support and practical guidance for the large-scale resource utilization of IRETs, promoting their application in silicate material production. This study identifies the common issues found in the research and provides recommendations for the high-value and large-scale resource utilization of IRETs in the future. Full article

Against the challenge of extreme lead (Pb) contamination (>15,000 ppm) in industrial polluted soils, where conventional agents fail to disrupt stable Pb–soil complexes—this study extends our prior cadmium (Cd) remediation research to validate amino acid ionic liquids (AAILs) for highly recalcitrant metals. Fifteen AAILs were screened via batch washing, with [Met][NO₃] (methionine-based) demonstrating the highest Pb removal efficiency. Single-factor optimization revealed that under the conditions of 0.8 mol/L, 6:1 liquid–soil ratio, 60 min, 85.4% Pb was removed from severely contaminated soil by [Met][NO₃]. Kinetic analysis using four common models showed that the second-order kinetic equation provided the best fit, indicating that Pb removal was predominantly driven by chemical reactions such as complexation or ion exchange. After washing, the contents of various Pb species were significantly reduced, thereby mitigating environmental risks. Notably, no substantial changes in soil texture were observed. However, a marked increase in organic matter content was detected, accompanied by decreases in soil pH and mineral element concentrations. Analysis of soil mineral composition, functional groups, and chemical speciation revealed that [Met][NO₃] primarily facilitated Pb removal through ion-exchange and coordination reactions. This study establishes [Met][NO₃] as a green agent with dual efficacy: it achieves high-efficiency remediation of severely Pb-contaminated soil while ensuring environmental sustainability, thus highlighting its potential for practical application. Full article

Natural polymers, such as gelatin, offer a sustainable, green, and versatile alternative for developing proton exchange membranes in low-temperature fuel cell applications. They provide a balance of biocompatibility, flexibility, and ionic conductivity. In this work, gelatin-based composite membranes are reported. The membranes were fabricated and modified with various additives, including ionic liquids (ILs), polyethylene glycol (PEG), and glycerol, to enhance their electrochemical and mechanical properties. The proton conductivity of the pure gelatin membrane was relatively low at 1.0368 × 10⁻⁴ Scm⁻¹; however, the incorporation of IL ([DEMA][OMs]) significantly improved it, with the gelatin/0.2 g IL membrane achieving the highest conductivity of 4.181 × 10⁻⁴ Scm⁻¹. The introduction of PEG and glycerol also contributed to enhanced conductivity and flexibility. The water uptake analysis revealed that IL-containing membranes exhibited superior hydration properties, with the highest water uptake recorded for the gelatin/0.2 g glycerol/0.2 g IL membrane, which was found to be very high (906.55%). The results showed that the combination of IL and PEG provided enhanced proton transport and mechanical stability (as examined visually), making these membranes promising candidates for fuel cell applications. Therefore, this study underscores the importance of bio-based materials by utilizing gelatin as a sustainable, biodegradable polymer, supporting the transition toward greener energy materials. The findings demonstrate that modifying gelatin with conductivity-enhancing and plasticizing agents can significantly improve its performance, paving the way for bio-based proton exchange membranes with improved efficiency and durability. Full article

Poly(ionic liquids) (PILs) show great promise as a new class of solid electrolytes for energy applications, including high-temperature polymer electrolyte fuel cells, owing to their combination of the unique electrochemical properties of ionic liquids and macromolecular architecture. In this study, we prepared and characterized PIL-based composite polymer electrolyte membranes containing silica nanofibers (SiO₂NFs). The SiO₂NFs were prepared via electrospinning, followed by calcination, and were used as a thermally and mechanically stable, porous substrate. The crosslinked protic PIL was synthesized via in situ radical polymerization of imidazolium hydrogensulfate-based reagents (one monomer and one crosslinker). It was then used as the membrane matrix. The prepared freestanding PIL membranes remained thermally stable at temperatures of up to 180 °C. Furthermore, the PIL/SiO₂NF composite electrolyte membranes demonstrated improved mechanical properties due to reinforcement by the NF framework. These composite membranes also exhibited relatively high proton conductivity (approximately 0.1 to 1 mS/cm) in the 100–150 °C temperature range. Full article

In response to the prevalent issues of short inhibition cycles and poor environmental compatibility in traditional inhibitors, this study prepared a new sepiolite-based composite inhibitor by loading imidazolium ionic liquid onto sepiolite. Through TG-DTG analysis, cone calorimeter experiments, and FTIR spectroscopy, we comparatively investigated the combustion characteristics of the composite inhibitor and its effects on the oxidation properties, inhibition performance, and active functional groups of coal samples. The results demonstrate that appropriate loading optimizes the thermal stability of sepiolite. Compared with conventional inhibitors, the composite exhibited the minimum weight loss rate at characteristic temperatures and achieved greater delays in critical temperature points of coal samples. The composite inhibitor delayed ignition time by 27–44 s compared to conventionally inhibited coal. The 3% [BMIM][BF₄]/sepiolite formulation showed CO emission peak intensity 3.02 times that of raw coal within 0–200 s, while reducing CO₂ production rate by 10.56% compared to MgCl₂-treated samples at 1000 s. The P_PFI exhibited maximum enhancement. Post-inhibition analysis revealed a 22–51% reduction in peak areas of active functional groups, indicating that the sepiolite-based composite achieves inhibition through synergistic physical and chemical interactions. Ultimately, a sepiolite-based composite inhibitor with environmental benignity was developed, whose inhibition performance is significantly enhanced compared to the traditional inhibitor MgCl₂. This research provides theoretical foundations for developing advanced inhibitor materials in coal mine applications. Full article

The effect of adding 10% biochar (B) or sludgechar (SL) on the water regime and adsorption properties of soils was tested on composites prepared by mixing two standard soils of loamy and clay type with B or SL in a 90:10 weight ratio. Water-holding capacity was assessed as initial (2 h) and equilibrium (24 h). Water retention time was estimated by evaporation from saturated samples at 20 °C to a constant weight. The composites exhibited a 60–90% increase in water absorption compared to the individual soils, retaining water up to 3–6 days longer than the individual soils. The adsorption properties were tested for cation (Pb²⁺) and anion (Sb(OH)₆⁻) adsorption and for Pb²⁺ and Sb(OH)₆⁻ co-adsorption from model solutions under laboratory conditions. All samples showed higher selectivity for Pb²⁺, with the adsorption efficiency from 40% to 99%. Sb(OH)₆⁻ adsorption achieved a maximum efficiency of only 10%. Pb²⁺ and Sb(OH)₆⁻ co-adsorptions were efficient for Sb(OH)₆⁻ adsorption, reaching efficiency levels above 95%. At prolonged reaction times, the adsorption efficiency elevated by more than 20%. Only 10% wt. addition of biochar or sludgechar enhanced not only the water regime of soils but also their adsorption capacity for ionic contaminants. Full article

In this paper, 8 mol% yttria cubic stabilized zirconia (8YCSZ) composites with reduced graphene oxide (rGO) contents up to 10 vol% were consolidated by spark plasma sintering (SPS) at two different temperatures with the aim of evaluating the relationship of their electrical properties with the graphene content, the rGO crystallinity, and the microstructural features. Successful in situ reduction of GO was accomplished during SPS, and highly densified composites with homogeneous rGO distribution, even at the highest contents, were obtained. The electrical properties were analyzed using impedance spectroscopy. Measurements were taken up to 700 °C, revealing an inductive response for the composites with 5 and 10 vol% rGO and a capacitive response for the composites with 1 and 2.5 vol% rGO. The results indicate that, along with the ionic conduction typical of zirconia, there are additional polarization mechanisms associated with the presence of graphene at ceramic grain boundaries that substantially modify the impedance response. A minor electronic conductivity contribution was identified in the composites below the percolation threshold. These characteristics make the 8YCSZ composites promising candidates for application as SOFC components, as ceramic interconnects when the graphene content is above the percolation threshold, or as electrolytes when the graphene content is below this limit. Full article

This study presents the electrical and optical properties of 35P₂O₅–xV₂O₅–(65–x) Sb₂O₃ glasses for 0 ≤ x ≤ 65 mol%. The direct current (DC) resistivity was measured by the Van der Pauw method and optical absorption spectra were taken in the Ultraviolet–Visible-Near-Infrared (UV–VIS–NIR) range. Electrical transport is attributed to simultaneous hopping of small polarons (SPs) between V⁴⁺ and V⁵⁺ (vanadium ion) sites and small bipolarons (SBPs) between the Sb³⁺ and Sb⁵⁺ (antimony ion) sites. The resistivity exhibits a non-linear dependence on the ionic fraction of vanadium (n_v), whereas the resistivity exhibits a minimum in the composition range 0 ≤ n_V ≤ 0.3, and a resistivity maximum was observed in the range 0.3 ≤ n_V ≤ 0.5. On further increasing n_v, the resistivity exhibits a monotonic decline. In the composition range 0 ≤ n_V ≤ 0.3, where the hopping distance between V ions decreases, while that between the Sb ions increases, the resistivity minimum has been shown to be the consequence of decreasing tunneling distance of SPs between the V⁴⁺ and V⁵⁺ ion sites. In the composition range 0.3 ≤ n_V ≤ 0.5, the resistivity, activation energy for DC conduction, glass transition temperature, and density exhibit their respective maxima even though the separation between the V⁴⁺ and V⁵⁺ sites continues to decrease. This feature is explained by enhanced localization of electrons on account of increased disorder (entropy) among the SPs and SBPs, like that of Anderson localization. This argument is further supported by a shift in the polaronic optical absorption bands associated with the SPs and SBPs toward higher energies. The transport behavior of all the glasses except the x = 0 composition has been explained by adiabatic transport, principally, by the SPs on V ions while the Sb ions contribute little to the total transport process. The results provide a clear relation between composition, polaron/bipolaron contributions, and conduction in these glasses. Full article

Low-salinity waterflooding (LSWF) enhances oil recovery at low cost in carbonate reservoirs, but its effectiveness requires the precise control of injected water chemistry and interaction with reservoir minerals. This study specifically investigates carbonated low-salinity waterflooding (CLSWF), where dissolved ${\mathrm{CO}}_2$ modulates geochemical processes. This study develops an integrated transport model coupling geochemical surface complexation modeling (SCM) with multiphase compositional dynamics to quantify wettability alteration during CLSWF. The framework combines PHREEQC-based equilibrium calculations of the Total Bond Product (TBP)—a wettability indicator derived from oil–calcite ionic bridging—with Corey-type relative permeability interpolation, resolved via COMSOL Multiphysics. Core flooding simulations, compared with experimental data from calcite systems at 100 ${}^{\circ }\mathrm{C}$ and 220 bar, reveal that magnesium ([${\mathrm{Mg}}^{2+}$]) and sulfate ([${\mathrm{SO}}_4^{2-}$]) concentrations modulate the TBP, reducing oil–rock adhesion under controlled low-salinity conditions. Parametric analysis demonstrates that acidic crude oils (TAN higher than 1 $\mathrm{m}$$\mathrm{g}$ KOH/$\mathrm{g}$) exhibit TBP values approximately $2.5 \mathrm{times}$ higher than those of sweet crudes, due to carboxylate–calcite bridging, while pH elevation (higher than 7.5) amplifies wettability shifts by promoting deprotonated ${\mathrm{-COO}}^{-}$ interactions. The model further identifies synergistic effects between ([${\mathrm{Mg}}^{2+}$]) (ranging from 50 to 200 mmol/kgw) and ([${\mathrm{SO}}_4^{2-}$]) (higher than 500 mmol/kgw), which reduce (${\mathrm{Ca}}^{2+}$)-mediated oil adhesion through competitive mineral surface binding. By correlating TBP with fractional flow dynamics, this framework could support the optimization of injection strategies in carbonate reservoirs, suggesting that ion-specific adjustments are more effective than bulk salinity reduction. Full article