Stability Of Interface Research Articles

Fabrication, characterization and simulated gastrointestinal digestion of sea buckthorn pulp oil microcapsule: effect of wall material and interfacial bilayer stabilization.

Sea buckthorn (Hippophae rhamnoides L.) pulp oil is rich in functional components; however, low water solubility and stability limit its applications. This study fabricated sea buckthorn pulp oil microcapsules using whey protein isolate (WPI), soy protein isolate (SPI), sodium caseinate (NaCN), gum arabic (GA), starch sodium octenylsuccinate (OSAS) and SPI mixed with chitosan (CHI). The influences of these wall materials on physicochemical properties, release behavior and digestibility were explored. Protein-based wall materials (WPI, NaCN, SPI) demonstrated lower bulk densities due to their porous structures and larger particle sizes, while GA and OSAS produced denser microcapsules. Encapsulation efficiency was the highest for protein-based microcapsules (79.41-89.12%) and the lowest for GA and OSAS. The surface oil percentage of protein-based microcapsules (1.41-4.40%) was lower than that of the other microcapsules. Protein-based microcapsules showed concave and cracked surfaces, while GA and OSAS microcapsules were spherical and smooth. CHI improved reconstitution performance, leading to faster dissolution. During simulated gastrointestinal digestion, protein-based microcapsules released more free fatty acids (FFAs) in the intestinal phase, while CHI-modified SPI microcapsules showed a delayed release pattern due to thicker walls. Protein-based wall materials were more effective for sea buckthorn pulp oil microencapsulation, providing higher encapsulation efficiency, better flow properties and releasing more FFAs. The addition of CHI led to the layer-by-layer self-assembly of the microcapsule wall and resulted in sustained release during in vitro intestinal digestion. These findings suggested the potential of protein-based microcapsules for targeted delivery and improved applications of bioactive oils in the food industry. © 2024 Society of Chemical Industry. Published by John Wiley & Sons Ltd.

Enhancing the interface stability of Li/NCM622 batteries by adding 3-trifluoromethyl pyrazole

In this study, 3-trifluoromethylpyrazole (TMPZ) was developed as a multifunctional electrolyte additive to enhance wettability between separator and electrolyte, CEI formation and remove HF to improve the performance of Li/NCM622 batteries by experiment and theoretical calculation. After 200 cycles at 30 °C, the discharge capacity retention of batteries at 1 C with 0.5 wt% TMPZ additive is remarkably enhanced from 68.3 % to 83.2 %. The enhanced electrochemical performance of the batteries by adding TMPZ additive is evaluated by the spectroscopic characterization and theoretical calculation. It is demonstrated that TMPZ can generate uniform and dense CEI film via ring-opening electrochemical polymerization of TMPZ on the NCM622 electrode surface. The CEI film helps to suppress the breakdown of LiPF6 electrolyte and the leaching of transition metals, effectively avoiding harmful side reactions between the NCM622 electrode and the electrolyte. Furthermore, introducing TMPZ can enhance the wettability between separator and electrolyte, therefore providing more channels of Li+ to accelerate reaction kinetics of batteries.

Mechanically Robust Polyimide Binder Realizes Stable and High Electrochemical Performance for Micro-Silicon Anodes in Lithium-Ion Batteries.

Silicon is regarded as a highly promising anode material for lithium-ion batteries, attributed to its substantial theoretical specific capacity. The practical implementation of Si-anodes is hindered by side reactions and significant volumetric changes, ~300% to 400%, occurring during the lithiation/delithiation processes. Pertinent binders can effectively mitigate the stress resulting from the volumetric exchange in Si-anodes. Herein, we developed a mechanically stable polyimide binder PI-CF3 and introduced trifluoromethyl and hydroxyl groups for commercial microparticular Si-anodes. With the highest Young's modulus of ~921.1 MPa, the binder presented the maximum resilience during the charging and discharging of Micro-Si, integrating the morphology, and reducing the degree to which the electrode disrupted ion and electric pathways. Moreover, -OH and -CF3 groups of the binder could potentially interact with the oxide layer at the surface of silicon through H-bonds resulting in a cross-linking network to improve interface stability. The as-prepared PI-CF3 binder with excellent intrinsic mechanical and electro-rich groups stabilizes the electrode structure and facilitates fast Li+ transportation. Consequently, at 0.6 Ag-1, the micro-Si anode produced an initial specific capacity of 1838 mAh g-1 at Si 0.66 mg cm-2. Besides, at Si 0.78 mg cm-2 specific capacity retained around 1219 mAh g-1 over 330 cycles.

Interface Stability and Reaction Mechanisms of Li3YCl5Br with High-Voltage Cathodes and Li Metal Anode: Insights from Ab Initio Simulations.

Recent advancements in battery technology emphasize the critical role of solid electrolytes in enhancing the performance and safety of next-generation batteries. In this study, we investigate the interface stability and reaction mechanisms of Li3YCl5Br, a promising halide-based solid electrolyte, in contact with high-voltage Ni-Mn-Co (NMC) cathodes and a Li metal anode using ab initio molecular dynamics simulations. Our findings reveal that Li3YCl5Br reacts with charged NMC cathodes. This reaction involves changes in the oxidation states of Br- anions in Li3YCl5Br and d-element cations in NMC, as well as the diffusion of Li ions from the solid electrolyte to the cathode to maintain charge balance. The reaction is confined to the interface, suggesting bulk stability. Conversely, the Li/Li3YCl5Br interface exhibits significant instability, with a chemical reaction that results in substantial structural changes and the formation of LiCl and LiBr at the solid electrolyte surface and metallic Y at the Li anode surface. These insights provide valuable information for optimizing interfacial design, aiming at improving the performance and reliability of all-solid-state batteries using halide solid electrolytes.

Coaxial Nanofiber Binders Integrating Thin and Robust Sulfide Solid Electrolytes for High‐Performance All‐Solid‐State Lithium Battery

AbstractTo access the theoretically high energy density of sulfide‐based all‐solid‐state lithium batteries (ASSLBs), a thin and robust sulfide electrolyte membrane is essential. Given the pivotal role of binder in preserving the structural integrity and interfacial stability of sulfide electrolytes upon cycling, it is desired to integrate binding capability, toughness, and stiffness into one binder, yet remains difficult. Herein, this challenge is addressed using a nanofiber‐reinforced strategy in the solvent‐free dry‐film process. A coaxial polyvinylidene poly(vinylidene fluoride‐co‐hexafluoropropylene) @ thermoplastic polyurethane (PVDF‐HFP@TPU) nanofiber binder is embedding into a Li6PS5Cl (LPSCl) matrix to obtain a sulfide thin‐layer (LPSCl‐P@T). During hot calendering of the sulfide‐binder mixture, the PVDF‐HFP shell layer melts and tightly binds LPSCl particles. The underlying TPU core layer, which maintains the fibrous structure, reinforces the structural stability of the membrane. Particularly, the fiber‐matrix connection is improved with the assistance of the molten PVDF‐HFP, collectively contributing to the effective dissipation of the mechanical stress. Controlled fusion of the core‐shell nanofiber also leads to enhanced interfacial anchoring of the cathode and electrolyte. The assembled cells with LPSCl‐P@T deliver stable cycling performances. The PVDF‐HFP@TPU nanofiber binder overcomes the long‐existing incompatible problems between binder toughness and stiffness, and shows promises in developing high‐performance sulfide‐based ASSLBs.

Super SEI-Forming Anion for Enhanced Interfacial Stability in Solid-State Lithium Metal Batteries.

The extremely high chemical reactivity of lithium metal (Li°) electrodes and its enormous volume change during repetitive cycles cause continuous interfacial degradations in prevailing organic electrolytes, thus deteriorating the cycling performances of rechargeable lithium metal batteries (LMBs). Herein, departing from traditional wisdom on the design of electrolyte components, a super SEI-forming anion (SSA), as an efficient percussor for building stable interphases on Li° electrode, is proposed. Comprehensive investigations related to the unique anion chemistry of SSA reveal that the sulfonate and polyfluoroalkyl functionalities synergistically contribute to uniform spatial distributions of designer interfacial species, greatly improving the surface coverage property and conformal ability of the resulting interphases. Consequently, the incorporation of SSA leads to significant improvements in the cyclability of Li° electrode (exceeding 575 mAh cm-2 before failure) and the corresponding rechargeable Li°||LiFePO4 cells [a five-time increase in lifespan as compared to the benchmark cell with the popular SEI-forming anion bis(fluorosulfonyl)imide (FSI)]. The present work offers a paradigm shift to tame the notorious interfacial issues via upgraded anion chemistry, which can promote the practical development of rechargeable LMBs and other kinds of metal batteries.

Unlocking Mechanism of Anion and Cation Interaction on Ion Conduction of Polymer Based Electrolyte in Metal Batteries.

Polymer based electrolyte shows advantages in compatibly improving safety and interface stability of batteries, while its limited ion conductivity and transfer number make it difficult to apply it in batteries with high energy density. Herein, by designing four crosslinking polyesters with different electron withdrawing group (EWG), it is found that strengthening the binding of EWG to anion for weakening the binding of anion to Li+ is critical for high Li+ transfer number (tLi+) and ionic conductivity of electrolyte. As a result, poly(2,2,3,3-tetrafluoropropyl methacrylate) (PTFM) based gel polymer electrolyte (GPE) shows an ionic conductivity of 0.78 mS cm-1 and a tLi+ of 0.85, much higher than those of poly(methyl methacrylate) (PMMA) without EWG. Moreover, PTFM based GPE shows excellent flame retardancy property. Li||PTFM||NCM811 batteries with an ultrahigh capacity of 5.5 mAh cm-2 show stable cycles of 5 times to that of Li||PMMA||NCM811. Moreover, the assembled graphite||PTFM||NCM811 pouch cell shows a capacity retention rate of 92% after 500 cycles. This work clarifies the mechanism of cation||anion interaction on ionic conductivity of GPE, which is important to develop high-performance devices with good safety and flexibility.

Low‐Temperature Sodium–Sulfur Batteries Enabled by Ionic Liquid in Localized High Concentration Electrolytes

AbstractLow ionic migration and compromised interfacial stability pose challenges for low‐temperature batteries. In this work, we discovered that even with the state‐of‐the‐art localized high‐concentration electrolytes (LHCEs), uncontrolled Na electrodeposition occurs with a huge overpotential of >1.2 V at −20 °C, leading to cell failure within tens of hours. To address this, we introduce a new electrolyte category that incorporates an ionic liquid as a key solvation species. Diverging from traditional LHCEs, the IL‐tailored LHCE facilitates an anion–solvent‐molecules exchange within the solvation sheath between Na+ and organic cations at low temperatures. This behavior reduces solvation cluster size and strengthens Na+–anion coordination, which proves instrumental in enabling fast ionic dynamics in both the bulk liquid and at the interface. Therefore, durable Na electrodeposition and shuttle‐free, 0.5 Ah sodium–sulfur pouch cells are achieved at −20 °C, for the first time, surpassing the limitations of typical LHCEs. This tailoring strategy opens a new design direction for advanced batteries operating in fast‐charge and wide‐temperature scenarios.

Unlocking Mechanism of Anion and Cation Interaction on Ion Conduction of Polymer Based Electrolyte in Metal Batteries

Polymer based electrolyte shows advantages in compatibly improving safety and interface stability of batteries, while its limited ion conductivity and transfer number make it difficult to apply it in batteries with high energy density. Herein, by designing four crosslinking polyesters with different electron withdrawing group (EWG), it is found that strengthening the binding of EWG to anion for weakening the binding of anion to Li+ is critical for high Li+ transfer number (tLi+) and ionic conductivity of electrolyte. As a result, poly(2,2,3,3−tetrafluoropropyl methacrylate) (PTFM) based gel polymer electrolyte (GPE) shows an ionic conductivity of 0.78 mS cm−1 and a tLi+ of 0.85, much higher than those of poly(methyl methacrylate) (PMMA) without EWG. Moreover, PTFM based GPE shows excellent flame retardancy property. Li||PTFM||NCM811 batteries with an ultrahigh capacity of 5.5 mAh cm−2 show stable cycles of 5 times to that of Li||PMMA||NCM811. Moreover, the assembled graphite||PTFM||NCM811 pouch cell shows a capacity retention rate of 92% after 500 cycles. This work clarifies the mechanism of cation||anion interaction on ionic conductivity of GPE, which is important to develop high‐performance devices with good safety and flexibility.

The impact of interface and heterostructure on the stability of perovskite-based solar cells

Perovskite solar cells have made significant progress in achieving high power conversion efficiency (>26%) in the past decade. However, achieving long-term stability comparable to established silicon solar cells is still a significant challenge, requiring further investigation into degradation mechanisms and continued exploration of interface engineering strategies. Here we review stability at the interfaces between perovskite and charge transport layers. These interfaces are particularly vulnerable to defects and degradation under external stresses such as heat, light, and bias, further compounded by their ionic nature and thermal expansion mismatch. To address these issues, strategies such as the use of additives, organic self-assembled monolayers, and low-dimensional perovskites have been developed to improve interface stability. These approaches enhance crystallinity, reduce defect-related recombination, and improve mechanical toughness.

Structure-property relationship of pea protein microgels as fat analogues in Pickering oil-in-water emulsions: effect of salt addition.

The design of plant-based microgels provides a platform for food ingredients to enhance palatability and functionality. This work aimed to explore the modifying effect of salt addition (KCl) on the structure of pea protein microgel particles (PPI MPs), on the interfacial adsorption and characteristics of formed emulsions as fat analogues. Salt addition (0-200 mmol L-1) promoted a structural transformation from α-helix to β-sheet, increased the surface hydrophobicity (from 1160.8 to 2280.7), and increased the contact angle (from 56.73° to 96.47°) of PPI MPs. The electrostatic shielding effect led to the tighter packing of MPs with irregular structures and lowered the adsorption energy barrier. Notably, salt-treated PPI MPs could adjust their adsorption state at the interface. The discernible adsorption of PPI MPs with 200 mmol L-1 salt addition that possessed enhanced anti-deformation ability dominated the interfacial stabilization, whereas a relatively rougher stretched continuous interfacial film formed after spreading and deformation of 0 mmol L-1 MPs. A tribological test suggested that emulsion stabilized by MPs at 0 (0.0053) and 80 mmol L-1 (0.0068) had similar friction coefficients to commercial mayonnaise (0.0058), whereas a higher salt concentration (200 mmol L-1) lowered its oral sensation due to the adsorption layer and enhanced the resistance to droplet coalescence during oral processing. Salt could be a modifier to tune the structure of microgels, and further promote the formation and attributes of emulsions. This study would improve application attributes of PPI MPs in the design of realistic fat analogues. © 2024 Society of Chemical Industry.

Nacre-inspired graphene oxide/polyethyleneimine-based ultra-thin heterogeneous superwetting membrane for highly stable separation of oil-in-water emulsions

Since the massive discharge of oily wastewater seriously affects both humans and natural development, the performance of conventional membrane materials in terms of interfacial stability and antifouling in the treatment of surfactant-containing emulsified oily wastewater is a major challenge. In this work, a novel nacre-inspired graphene oxide/polyethyleneimine-based ultra-thin chemically heterogeneous superwetting membrane was fabricated through vacuum-assisted self-assembly and post-modification methods for oil-in-water emulsion separation. The nacre-inspired heterogeneous membrane exhibited superhydrophilicity, underwater superoleophobicity (underwater oil contact angle was 157.7°), excellent crude oil adhesion resistance, high acid/alkaline stability, outstanding salt resistance, and good mechanical properties (Young’s modulus 1391.7 MPa). The heterogeneous membranes showed separation efficiencies of more than 99.9 % for a range of oil-in-water emulsions. The high-value membranes could achieve the permeances of 917–1256 L m−2h−1 bar−1 for pure water and 339.7–577 L m−2h−1 bar−1 for emulsion through a dead-end filter device, with the optimal long-term stable permeance only decreasing by 30.0 % compared to the initial value. After six test cycles, the membrane’s antifouling and self-cleaning properties were enhanced by constructing heterogeneous superwetting properties, and the flux recovery rate remained at 96.5 %. All of these results indicated that this method provides new ideas for the design and fabrication of highly stable and antifouling membrane materials.

An experimental study of transient front velocity for miscible exchange flow in a rectangular channel

ABSTRACT This experimental study considers the exchange flow of two miscible fluids in a rectangular channel. The main purpose is to understand the mixing dynamics and explore how mixing and different channel inclinations can affect variations in front velocity. In contrast to previous studies, no steady state is assumed. The larger channel cross-section used in the current study provides an opportunity to visualize and analyze the inertia dominated regime in finer details. For horizontal channels, after opening the gate valve and allowing the transient phase to pass, it is observed that the front velocity remains almost constant for a period before gradually decreasing. In inclined flows, the mixing and transition to inertia dominated flow begin when the viscous flow rate of the main flow increases. This flow rate may exceed the maximum flow rate that the front can tolerate according to the equations describing the momentum balance at the front. At sufficiently high density contrasts or large inclinations, the front velocity may continue to decrease as the flow progresses due to interfacial instabilities and mixing. Under such conditions, the results may also cast doubt on the presence of a true steady state front velocity in miscible exchange flow.

Dual-Anionic Coordination Manipulation Induces Phosphorus and Boron-Rich Gradient Interphase Towards Stable and Safe Sodium Metal Batteries.

High-voltage sodium metal batteries (SMBs) present a viable pathway towards high-energy-density sodium-based batteries due to the competitive cost advantage and abundant supply of sodium resources. However, they still suffer from severe capacity decay induced by the notorious decomposition of the electrolyte under high voltage and unstable cathode/electrolyte interphase (CEI). In addition, the high reactivity of Na metal and flammable electrolytes push SMBs to their safety limits. Herein, a special dual-anion aggregated Na+ solvation structure is designed in a nonflammable trimethyl phosphate-based localized high-concentration electrolyte, and a gradient CEI enriched with phosphorus and boron compounds is formed on the cathode. This thin and stable interphase effectively suppresses the parasitic reaction, improves the interfacial stability of the cathode, and facilitates Na+ transport through the interface by the synergistic effect of multi-components, thus optimizing the cycling stability and safety of SMBs. The Na0.95Ni0.4Fe0.15Mn0.3Ti0.15O2//Na batteries employing such electrolyte provide a discharge capacity of 167.5 mA h g-1 and high retention in the capacity of 85.2% after 800 cycles at 1 C. This approach offers a general strategy for the design of flame-retardant high-voltage electrolytes and the practical application of SMBs.

REVEALS: an open-source multi-camera GUI for rodent behavior acquisition.

Deciphering the rich repertoire of mouse behavior is crucial for understanding the functions of both the healthy and diseased brain. However, the current landscape lacks effective, affordable, and accessible methods for acquiring such data, especially when employing multiple cameras simultaneously. We have developed REVEALS (Rodent Behavior Multi-Camera Laboratory Acquisition), a graphical user interface for acquiring rodent behavioral data via commonly used USB3 cameras. REVEALS allows for user-friendly control of recording from one or multiple cameras simultaneously while streamlining the data acquisition process, enabling researchers to collect and analyze large datasets efficiently. We release this software package as a stand-alone, open-source framework for researchers to use and modify according to their needs. We describe the details of the graphical user interface implementation, including the camera control software and the video recording functionality. We validate results demonstrating the graphical user interface's stability, reliability, and accuracy for capturing rodent behavior using DeepLabCut in various behavioral tasks. REVEALS can be incorporated into existing DeepLabCut, MoSeq, or other custom pipelines to analyze complex behavior. In summary, REVEALS offers an interface for collecting behavioral data from single or multiple perspectives, which, when combined with deep learning algorithms, enables the scientific community to identify and characterize complex behavioral phenotypes.

Stabilization of single crystal LiNi0.90Mn0.05Co0.05O2 via ZrO2 dual-functional coating enables superior performance for solid-state lithium battery

Chlorine-rich argyrodites with ultrafast Li-ion conductivities exhibits great potential as solid electrolytes for all-solid-state lithium batteries. However, the poor interfacial stability and slow ion dynamics between Li5.5PS4.5Cl1.5 (Cl1.5) and high nickel layered cathode hinder the achievement of superior battery performances. Here, the prepared ZrO2 coating film was found to perform two functions: enhancing the bulk and interfacial stability of single crystal LiNi0.90Mn0.05Co0.05O2 (NCM911) towards sulfide, and facilitating Li-ion transport rates across the interface. A Li2ZrO3 phase with fast Li-ion diffusion rate generates during cycling and further improve the layered-structure integrity of NCM911 and interfacial stability toward the Cl1.5 electrolyte, which are due to the reduction of lattice oxygen release from NCM911 and the isolation of direct contact between the two materials. As a result, these effects enable superior electrochemical performances for the ZrO2-coated NCM911 than the bare sample in Cl1.5-based all-solid-state lithium batteries at varying C-rates and different operating temperatures. It delivers high initial discharge capacities of 156.6 mAh g−1 at 2C and retains 86.0 % of its capacity after 1000 cycles at room temperature, and displays an initial discharge capacity of 172.6 mAh g−1 at 0.5C under 60 °C and 142.4 mAh g−1 at 0.1C under –20 °C, respectively. This dual-functional surface modification strategy provides guidelines to stabilize high-nickel cathode in sulfide-based all-solid-state lithium batteries.

Immiscible non-Newtonian displacement flows in stationary and axially rotating pipes

We examine immiscible displacement flows in stationary and rotating pipes, at a fixed inclination angle in a density-unstable configuration, using a viscoplastic fluid to displace a less viscous Newtonian fluid. We employ non-intrusive experimental methods, such as camera imaging, planar laser-induced fluorescence (PLIF), and ultrasound Doppler velocimetry (UDV). We analyze the impact of key dimensionless numbers, including the imposed Reynolds numbers (Re, Re*), rotational Reynolds number (Rer), capillary number (Ca), and viscosity ratio (M), on flow patterns, regime classifications, regime transition boundaries, interfacial instabilities, and displacement efficiency. Our experiments demonstrate distinct immiscible displacement flow patterns in stationary and rotating pipes. In stationary pipes, heavier fluids slump underneath lighter ones, resulting in lift-head and wavy interface stratified flows, driven by gravity. Decreasing M slows the interface evolution and reduces its front velocity, while increasing Re* shortens the thin layer of the interface tail. In rotating pipes, the interplay between viscous, rotational, and capillary forces generates swirling slug flows with stable, elongated, and chaotic sub-regimes. Progressively, decreasing M leads to swirling dispersed droplet flow, swirling fragmented flow, and, eventually, swirling bulk flow. The interface dynamics, such as wave formations and velocity profiles, is influenced by rotational forces and inertial effects, with Fourier analysis showing the dependence of the interfacial front velocity's dominant frequency on Re and Rer. Finally, UDV measurements reveal the existence/absence of countercurrent flows in stationary/rotating pipes, while PLIF results provide further insight into droplet formation and concentration field behavior at the pipe center plane.

Interfacial space confinement engineering toward ultrastable all-climate aqueous zinc ion batteries

The interfacial instability, particularly uncontrollable Zn nucleation and deposition, significantly impeding the commercialization of aqueous zinc ion batteries (ZIBs). Herein, we propose an interfacial space confinement strategy to enable the dendrite-free anode, specifically through constructing a zincophilic buffer layer based on hollow Sn@C. The porous Sn@C contributes to modify the electrical double layer structure, which greatly alleviates the concentration polarization during high-rate plating. In-situ experimental results demonstrate the inhibited H2O-mediated parasitic side reactions and the absence of dendrite deposition morphology. Based on the improved thermodynamics and kinetics, zincophilic buffer layers can deliver low nucleation overpotential (20 mV), ultrastable cycle life (> 5000 h), and excellent zinc utilization rate (62.4%). Importantly, the full batteries with zincophilic buffer layer exhibit excellent electrochemical stability over -40 to 70 °C, pushing forward the construction of advanced all-climate ZIBs.

Reversible silicon anodes enabled by fluorinated inorganic-organic hybrid coating

Silicon anodes deliver batteries with energy densities much higher than those based on today’s dominant graphite anodes. However, they commonly exhibit huge volume variations and unfavorable interface stability, causing a gradually diminishing capacity on extended cycling. Most Si-based batteries consisting Si/C composites in industry can only use a very limited amount of Si (<30 % by weight). Exploiting molecular layer deposition (MLD) technique, a fluorine-rich flexible inorganic–organic hybrid alucone (AlFHQ) shell is controllably deposited onto Si electrodes. Employing ex situ XPS and AFM, the AlFHQ film presents reversible electrochemical evolutions in terms of composition and morphology. The interactions the between Li+ and −O−2,3,5,6-fluorobenzene functional groups help to construct a mechanically-chemically robust LiF-rich hybrid solid electrolyte interphase (SEI) on Si anode, delivering enhanced interfacial stability and integrity of electrode. An optimized coating thickness (≈5 nm) for interfacial stabilization and Li+ transport kinetics is demonstrated, namely, Si@AlFHQ-20. The reported fluorine-rich hybrid modification technique endows (a), stable cycling of Si anode (≈3.8 mAh cm−2) with an ultrahigh initial Coulombic efficiency (ICE) of 92.3 %; (b), enhanced rate capability of 1468 mAh/g at 2.0 A g−1 and good cycling performance; and (c), overall cell (Si@AlFHQ-20//LiCoO2@Al2O3) operational stability for more than 100 cycles under stringent cathode conditions (2.68 mAh cm−2, high cutoff voltage at 4.55 V).

Hydrodynamics of liquid–liquid parallel flow in novel microextractors: Review

Parallel flows on microfluidic platforms enable continuous liquid–liquid operations and inline separation of effluent streams, bearing immense scope in integration of miniaturized separation processes. However, these flows face major challenges including low mass transfer efficiency due to lack of transverse convection and flow instability at low flow rates, which undermine their operating range and utility. The limitations have inspired dedicated research, delving into the fundamentals of fluid flow and transport mechanism and exploring novel configurations of microextractors. The current article summarizes the hydrodynamics of parallel flows and relevant process intensification strategies in microfluidic extractors, evolving from the use of straight to curved and helical geometries, besides elucidating unique secondary flow patterns observed in-state-of-the-art designs. It includes exclusive sections addressing various aspects of parallel flows: (i) flow inception and theoretical modeling of flow fields and phase hold up, (ii) challenges concerning interfacial stability and flow intensification, (iii) curvature effects in planar curved geometries, and (iv) curvature cum torsional effects in unique multi-helical configurations. The theoretical perspective of this review presents a roadmap that can provide further insights into design modifications for developing improved integrated microextractors based on parallel flows.