Interfacial Reaction Research Articles

High-performance PEI-based nanofiltration membrane by Mxene-regulated interfacial polymerization reaction: Design, Fabrication and Testing

Development of cost-effective materials and technologies for lithium extraction in salt-lake brines is of great importance to meeting rising lithium demands. Nanofiltration (NF) process is a feasible solution, however, it has commonly had operational problems such as low permeability. In this study, an MXene-regulated interfacial polymerization (MRIP) method was developed for fabrication of high-performance polyethyleneimine (PEI)-based polyamide (PA) NF membrane. The MXene nanosheets tiled at the water-oil interface, by which a spatio-temporal confinement effect was created; such structure could nicely regulate diffusion of monomers and precisely control PA nanofilm. The MXene-regulated membrane (PA@M) had thinner thickness, larger pore size, and better hydrophilicity. As a result, the permeance of PA@M membrane was significantly increased by more than 300%. Moreover, the membrane had outstanding cation selectivity with >98% rejection for Mg2+ and <20% rejection for Li+. Meanwhile, the selectivity factor of Li+/Mg2+ reached 31.5. Furthermore, a two-stage nanofiltration process by the membrane could reduce the Mg2+/Li+ ratio from 40 to 0.45, suggesting greater suitability of membrane for lithium extraction. The MRIP method offers a promising strategy and method for development of high-performance PA-NF membranes for resource recovery and water purification applications.

Yttrium aluminum garnet fluorescent conversion films for solid-state lighting: interface reaction synthesis strategy and modulation of warm white light.

Traditional preparation of yttrium aluminum garnet (YAG) transparent ceramics involves several steps, including powder preparation, molding process and sintering at high temperature. Herein, a new and simple method was developed to prepare YAG transparent polycrystalline films directly through a novel interface reaction between sapphire and a Y2(OH)x(CO3)y(NO3)(6-x-2y)·nH2O film attached to the sapphire. The prepared YAG:5%Ce transparent polycrystalline film could be combined with a blue chip to obtain fluorescence-converted white LED, with a CCT of 6361 K and a CRI (Ra) of 73.3. Introducing 1%Pr into the YAG:5%Ce system increased the CRI (Ra) to 77.4. When these transparent polycrystalline films were combined with a blue light laser diode (LD), similar spectra were obtained under high power density (4.17 W mm-2) excitation. YAG:5%Ce films produced a white light CCT of 5471 K, LE of 165.1 lm W-1, and Ra of 62.9, while YAG:5%Ce,1%Pr films produced a CCT of 6311 K, LE of 146.5 lm W-1, and Ra increased to 69.7. This study provides a novel "powder-free" and "glue-free" synthesis strategy for preparing fluorescence-converted YAG:Ce,Pr transparent polycrystalline films, which not only overcomes the disadvantages of traditional transparent ceramic preparation methods, such as time consumption, energy consumption, and equipment dependence, but also avoids the problem of aging in traditional fluorescent conversion materials.

Direct Evaluation of the Electrode/Electrolyte Interface with Additives by Single-Particle Electrochemical Measurement.

To achieve high-performance lithium-ion batteries (LIBs), controlling interfacial reactions at the electrode/electrolyte interface is intensely studied by introducing chemical additives into the electrolyte solution. These additives preferentially decompose over other electrolyte components, forming a stable interphase film at the electrode/electrolyte interface, which protects against capacity degradation and overcharging. However, the composite nature of conventional LIB electrodes makes it challenging to directly observe the electrochemical properties and formation process of the passivation film on the active material alone. To address this challenge, we used single-particle electrochemical measurement (SPEM), which uses an open-type measurement cell, enabling the direct observation of resistance component changes within a single particle during the in-situ introduction of additives. In this study, SPEM was applied to a LiCoO2 single particle (LCO-SP) to evaluate changes in electrochemical and resistance properties with the in-situ introduction of an additive solution under a charged state. The electrolyte solution and additive used were 1.0 mol kg-1 ethylene carbonate-LiN(SO2F)2, with LiPO2F2 as the additive avoiding concentration changes of LiN(SO2F)2. In the additive-free system, SPEM and AC impedance measurements revealed a single asymmetric semicircular arc, indicating resistance components related to the internal LCO SP, charge transfer, and the interphase layer at the electrode/electrolyte interface. In the additive-containing system (1.0 wt %), the semicircular arc from AC impedance measurements exhibited a decrease in time constant and slight noise, suggesting changes in the charge transfer process. Upon in-situ introduction of the additive under a charged state, the impedance spectra exhibited two semicircular arcs and an increasing trend in the resistance of their lower frequency component, while maintaining potential, attributed to the growth of the interphase layer at the LCO SP/electrolyte interface. Therefore, SPEM enables direct and precise observation of resistance behavior at the electrode/electrolyte interface on a single particle scale during additive introduction.

Dual Breaking of Electron Cloud and Space Structure Symmetry Induced Microscopic Split-phase Interface for High-rate and Long-term Aqueous Zinc Batteries.

Weak dipole interactions between highly symmetric H2O molecules and SO42- species are the root cause of unstable electric double layer (EDL), which triggers the hydrogen evolution reaction and Zn dendrite formation, significantly impeding the commercialization of aqueous zinc-ion batteries. Herein, we designed a microscopic split-phase interface (MSPI) by dual breaking of electron cloud and space structure symmetry to suppress interfacial side reactions and achieve uniform Zn deposition. The structurally asymmetric methylurea (MU) molecules possess both hydrophobic methyl and hydrophilic amino groups, which disrupt the continuity of H-bonding network and the aggregation state of H2O molecules, resulting in peculiar nanoscale core-shell-like clusters. Such a unique structure further evolves into MSPI at the electrode-electrolyte interface, ensuring a continuously stable EDL. The DRT analysis and MD simulation confirmed that MSPI structure is composed of the outer H2O layer and the inner MU layer, which greatly suppress the activity of H2O molecules and accelerate Zn2+ migration. Consequently, the formulated electrolyte exhibited remarkable cycle reversibility over 1500 h at a high current density of 20 mA·cm-2, achieving a record-high cumulative capacity of 30 Ah·cm-2. Additionally, its feasibility was demonstrated by coupling with the I2@AC cathode, achieving an impressive 28,000 cycles at 10 A·g-1.

Diffusion/Modulator Dual-Mediated Solid-Liquid/Vapor Interfacial Synthesis of Crystalline Covalent Organic Framework Membranes.

Constructing oriented crystalline covalent organic framework (COF) membranes with controllable thickness for water purification is highly desirable. Herein, we present a simple and universal protocol to prepare high-quality COF membranes on the inner wall of a glass vessel using a diffusion/modulator dual-mediated solid-liquid/vapor interfacial synthesis strategy. By meticulous control of the solvent and temperature, a thin supersaturated spreading liquid layer was formed on the glass wall surface and served as a confined microreactor for incubating crystal nuclei. This induced the aniline-modulated solid-liquid/vapor interfacial exchange reaction and upward growth of a highly ordered COF membrane. The experiments and theoretical simulations revealed the underlying mechanisms of solid-liquid/vapor interfacial nucleation, growth and crystallization. Using this strategy, we created 13 types of new, free-standing, imine-linked COF membranes with exceptional performances in crystallinity, porosity, stability, processability and adsorption capacity. As an application demonstration, a COF membrane-filled filter was coupled with high-performance liquid chromatography system for the automated removal of multitarget liquid-crystal monomers in real water samples (removal efficiency ≥ 96%). This study enriches the synthesis toolboxes of COF membranes and broadens their application scopes.

Protective Coating of Single-Crystalline Ni-Rich Cathode Enables Fast Charging in All-Solid-State Batteries.

Improving interfacial stability between cathode active material (CAM) and solid electrolyte (SE) is vital for developing high-performance all-solid-state batteries (ASSBs), with compatibility issues among the cell components representing a major challenge. CAM surface coating with a chemically inert ion conductor is a promising approach to suppress side reactions occurring at the cathode interfaces. Another strategy to mitigate mechanical degradation involves utilizing single-crystalline particle morphologies. Their more robust bulk structure and lower tortuosity for charge transport, compared to polycrystalline (PC) CAMs, can significantly enhance cyclability in ASSBs. Herein, we coated a LiNbO3 protective layer onto the free surface of quasi single-crystalline LiNi0.83Co0.12Mn0.05O2 (SC83) particles. Pellet-stack ASSB cells using the LiNbO3@SC83 CAM and argyrodite Li6PS5Cl as SE showed a capacity retention of 88% after 1000 cycles at the 1 C rate, compared to only 71% for the uncoated counterpart and far superior to that of LiNbO3@PC83 (30%). The effectiveness of LiNbO3 coating and the SC-NCM nature in mitigating electro-chemo-mechanical degradation was studied by combining modeling and physical/electrochemical characterizations. We demonstrate that the capacity decay at fast charge is due primarily to the mechanical degradation of CAM particles, while it is strongly determined by CAM|SE interfacial reactions under slow-charging conditions.

Understanding the CMAS corrosion behavior of high‐entropy (La0.2Sm0.2Er0.2Y0.2Yb0.2)2Ce2O7

AbstractCeramic thermal barrier coating (TBC) materials are used to protect the superalloys from the damage of harmful high‐temperature airflow and improve the efficiency of jet and gas turbine engines. However, the long‐term application of TBC materials and the robustness of these materials can be destroyed by aggressive calcium‐magnesium‐alumina‐silicate (CMAS) melt during high‐temperature service. Increasing the configuration entropy of material by doping multiple principal components has become a research hotspot in the design of corrosion‐resistant thermal barrier coating material and has opened an infinite space of chemical composition, structure, and material properties. In this study, high‐entropy (La0.2Sm0.2Er0.2Y0.2Yb0.2)2Ce2O7 was synthesized and its CMAS corrosion behavior was investigated by experimental investigation and first‐principles calculation. The effects of the increase of configurational entropy and the subsequent potential effects on the CMAS corrosion behavior of Ce‐based fluorite oxides have been sufficiently investigated. By compared with control samples, the high‐entropy (La0.2Sm0.2Er0.2Y0.2Yb0.2)2Ce2O7 possesses the minimum infiltration depth of CMAS melts and the denser corrosion reaction layer, indicating the best corrosion resistance. The corrosion resistance mechanism of high‐entropy (La0.2Sm0.2Er0.2Y0.2Yb0.2)2Ce2O7 was studied by first‐principles calculation. The greater stability and resistance to segregation of CMAS melt in the CMAS/(La0.2Sm0.2Er0.2Y0.2Yb0.2)2Ce2O7 system, the poor adsorption capacity for CMAS melt which leads to a weak infiltration ability of CMAS melt; the weakest interfacial chemical reaction at the interface indicated by the smallest value of Griffith rupture work and the least species migration of high‐entropy fluorite oxide can be responsible to the enhanced corrosion resistance. Our work reveals that increasing the configuration entropy can be an effective strategy for TBC material to enhance corrosion resistance.

Preparation of Octacalcium Phosphate Thin Film with Exposing Reactive Crystalline Plane in Biological Fluid.

Octacalcium phosphate (OCP) has been used as a bone replacement material due to its higher bone affinity. However, the mechanism of affinity has not been clarified. Since the 100 crystalline plane of OCP is closely involved in the biological reactions during osteogenesis, it is important to expose the 100 crystalline plane of OCP to the biological fluid to precisely measure the interfacial reactions. In this study, the OCP plate-like crystals were fixed on a conductive substrate in the form of single-particle deposition, and the thin films with exposing 100 crystalline planes were fabricated. Then, the characteristics of hydration layers in the OCP crystals were enhanced by the exposure of 100 crystalline planes through the thin film formation, and the bioreactivity was found to be associated with the swelling and dissolution of the hydration layer in the biological fluid. Specifically, the OCP crystals were deposited on the gold sensor by electrophoretic deposition (OCP/Au-1). The results showed that the OCP plate-like crystals were selectively deposited on the gold sensor by electrophoresis. Subsequently, it was found that the ultrasonication of OCP/Au-1 resulted in the formation of an OCP crystalline thin film (m-OCP/Au-1) with the single-particle thickness on the gold sensor with exposing 100 crystalline planes. Moreover, the FT-IR spectra of m-OCP/Au-1 showed that the structure of the phosphate ions was rearranged by ultrasonication in the hydration layer, resulting in the regulation of the layered nanostructures, promoting higher crystallinity. Furthermore, the XPS spectra of m-OCP/Au-1 indicated that the hydrogen phosphate ions in the hydration layer were exposed on the 100 crystalline plane of the topmost surface. The prepared m-OCP/Au-1 was stable in citrate buffer, whereas it showed very high reactivity in phosphate buffer as the hydration layer gradually dissolved after the swelling, which was measured by the QCM-D technique. Therefore, the OCP crystalline thin films in this study were found to have higher surface reactivity due to the enhanced exposure of the hydration layer, which is assumed to be the cause of their bone-regeneration-promoting effect (i.e., higher bone affinity). The films in this study were stable at gastric acid pH and dissolved at neutral pH, which could make them useful as the orally administered drug carrier.

Influence of π-π interactions on organic photocatalytic materials and their performance.

Currently, organic photocatalyst-based photocatalysis has garnered significant attention as an environmentally friendly and sustainable reaction system due to the preferable structural flexibility and adjustable optoelectronic features of organic photocatalysts. In addition, π-π interactions, as one of the common non-bonded interactions, play an important role in the structure and property adjustments of organic photocatalysts due to their unique advantages in modulating the electronic structure, facilitating charge migration, and influencing interfacial reactions. However, studies summarizing the relationship between the π-π interactions of organic photocatalysts and their photocatalytic performance are still rare. Therefore, in this review, we introduced the types of π-π interactions, characterization techniques, and different types of organic photocatalytic materials. Then, the influence of π-π interactions on photocatalysis and the modification strategies of π-π interactions were summarized. Finally, we discussed their influence on photocatalytic performance in different photocatalytic systems and analyzed the challenges and prospects associated with harnessing π-π interactions in photocatalysis. The review provides a clear map for understanding π-π interaction formation mechanism and its application in organic photocatalysts, offering useful guidance for researchers in this field.

Diatomite-Based Hybrid Electrolyte for Improving Reversibility of Cathode/Anode Interface Reaction in Zn-MnO2 Batteries.

The cyclic stability of aqueous zinc-manganese batteries (ZMBs) is greatly restricted by the side reaction of the anode and the irreversibility of the cathode. In this work, a solid-liquid hybrid electrolyte mixing by traditional ZnSO4-based electrolyte and diatomite (denoted as Dtm) is proposed that exhibits good compatibility and reversibility in both the anode interface and the cathode interface. The abundant hydroxyl groups at the anode interface disturb the hydrogen bond network of water molecule, which weakens the corrosion of the active water to Zn anode. Moreover, the negatively charged surface of diatomite is able to regulate the electric field at the anode interface to promote the uniform deposition of Zn ion as well as inhibit the formation of Zn hydroxyl sulfate (ZHS) at the anode interface. As a result, Zn||Zn symmetric battery with Dtm achieves a stable cycling for 2500h at 1mA cm-2/1 mAh cm-2, while Zn||MnO2 battery can achieve a stable cycle time of 500 cycles at current densities of 0.2 and 0.5 A g-1 with capacities of 228 and 177.6 mAh g-1, respectively. The Dtm provides new ideas for electrolyte screening for high-performance aqueous ZMBs.

The construction of coupling degradation system low temperature plasma and microbiological denitrification: Interfacial reaction process and synergistic mechanism.

The degradation of antibiotic wastewater by low-temperature plasma and the removal of excess nitrogen by biological denitrification with Pseudomonas stutzeri (P. stutzeri) reducing secondary pollution has rarely been reported. In this study, iron and phenolic resin doped carbon-based porous nanofiber membranes are prepared (named RFe2-CNF) by electrostatic spinning technique, where the optimization of structure and composition endows low-temperature plasma system better catalyst performance than that of without catalyst (a 58% increase). Microbiological treatment experiments show that the plasma-degraded solution inhibits the denitrification of the P. stutzeri, but overall shows a strong denitrification effect (93.1%). In the coupling process of advanced oxidation technology and microbial denitrification technology, the possible interfacial reaction process, synergistic degradation mechanism, and products toxicity analysis are studied in detail. In addition, LC-MS and DFT are used to derive possible degradation pathways of pollutants. This work provides a new strategy to improve the degradation performance meanwhile reducing secondary pollution by low-temperature plasma-coupled microbiological treatment.

Hydrogen Tunneling and Conformational Motions in Nonadiabatic Proton-Coupled Electron Transfer between Interfacial Tyrosines in Ribonucleotide Reductase.

Ribonucleotide reductase (RNR) is essential for DNA synthesis and repair in all living organisms. The mechanism of E. coli RNR requires long-range radical transport through a proton-coupled electron transfer (PCET) pathway spanning two different protein subunits. Herein, the direct PCET reaction between the interfacial tyrosine residues, Y356 and Y731, is investigated with a vibronically nonadiabatic theory that treats the transferring proton and all electrons quantum mechanically. The input quantities to the PCET rate constant expression are computed with a combination of density functional theory and molecular dynamics simulations. The calculations highlight the importance of hydrogen tunneling in this PCET reaction. Compression of the distance between the proton donor and acceptor oxygen atoms of the interfacial tyrosine residues is essential to facilitate hydrogen tunneling by increasing the overlap between the reactant and product proton vibrational wave functions. This compression occurs by thermal conformational fluctuations of these interfacial tyrosine residues. N733 and R411 are identified as key residues that can hydrogen bond to Y731 and Y356, respectively, and thereby compete with the hydrogen-bonding interaction between Y731 and Y356 required for direct PCET. Understanding the roles of hydrogen tunneling and conformational motions in this interfacial PCET reaction, as well as identifying other residues that may impact the kinetics, is important for targeted protein engineering efforts to modulate RNR activity.

Sensitivity-enhanced hydrogel digital RT-LAMP with in situ enrichment and interfacial reaction for norovirus quantification in food and water.

Low levels of human norovirus (HuNoV) in food and environment present challenges for nucleic acid detection. This study reported an evaporation-enhanced hydrogel digital reverse transcription loop-mediated isothermal amplification (HD RT-LAMP) with interfacial enzymatic reaction for sensitive HuNoV quantification in food and water. By drying samples on a chamber array chip, HuNoV particles were enriched in situ. The interfacial amplification of nucleic acid at the hydrogel-chip interface was triggered after coating HD RT-LAMP system. Nanoconfined spaces in hydrogels provided a simple and rapid "digital format" to quantify single virus within 15 min. Through in situ evaporation for enrichment, the sensitivity level was increased by 20 times. The universality of the sensitivity-enhanced assay was also verified using other bacteria and virus. Furthermore, a deep learning model and smartphone app were developed for automatic amplicon analysis. Multiple actual samples, including 3 lake waters, strawberry, tap water and drinking water, were in situ enriched and detected for norovirus quantification using the chamber arrays. Therefore, the sensitivity-enhanced HD RT-LAMP is an efficient assay for testing biological hazards in food safety monitoring and environmental surveillance.

Design Strategies for Practical Zinc‐Air Batteries Toward Electric Vehicles and beyond

AbstractZinc‐air batteries (ZABs) offer promising forthcoming large‐scale high‐density storage systems and the cost‐effectiveness of electrode materials, specifically in solid‐state and liquid electrolytes. However, the uncontrolled diffusion and utilization of irreversible zinc components and cell design principles limit practical applications with severe capacity fade and interfacial reactions. In this perspective article, the aim is to shed lights on the underlying mechanisms of solid electrolytes and interfaces alongside the current status and prospective research insights. Formulations of ampere‐hour (Ah)‐scale cylindrical/pouch cells are discussed for 100–500 Wh kg−1 cell‐level energy metrics under realistic operations. The electrode/electrolyte interface dynamics, scale‐up readiness, testing protocols, and key performance metrics are also suggested for transforming lab‐scale research into practical production.

Simultaneous regulation of grain size and interface of single-crystal ultrahigh-nickel LiNi0.9Co0.055Mn0.045O2 via one-step Li2ZrO3 coating.

Single-crystal ultrahigh-nickel LiNixCoyMn1-x-yO2 (NCM) materials are recognized for significant potential in the development of high-performance lithium-ion batteries, primarily owing to their higher energy density and superior cycling performance compared to polycrystalline counterparts. However, these materials require high calcination temperatures, suffer from significant lithium/nickel mixing, and face challenges in composition control. Although high-activity oxide precursors prepared via spray pyrolysis can reduce calcination temperatures, the smaller particle size of the resulting NCM materials intensifies interfacial side reactions. In this study, we addressed these challenges by coating LiNi0.9Co0.055Mn0.045O2 (NCM90) with Li2ZrO3 through low-temperature annealing, which integrates grain size regulation and interface modification in one step. Morphology and structure analysis show that the applied coating increased the particle size from 0.3μm to 0.75 μm, preserved a more reversible crystalline structure in the lithium-deficient state, and reduced the volumetric shrinkage of NCM during cycling. The initial discharge capacity (212mAh/g at 0.1 C) and 100 cycle capacity retention (88%) of the optimal material (Li2ZrO3 loading of 0.16wt%) significantly exceeded those of unmodified NCM90 and C-NCM90 prepared from a commercial precursor. This proposed "two birds with one stone" strategy offers a promising approach for developing single-crystal ultrahigh-nickel cathode materials and, consequently, high-performance lithium-ion batteries.

Cellulose Elementary Fibrils as Deagglomerated Binder for High-Mass-Loading Lithium Battery Electrodes

Amidst the ever-growing interest in high-mass-loading Li battery electrodes, a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways. Here, we propose cellulose elementary fibrils (CEFs) as a class of deagglomerated binder for high-mass-loading electrodes. Derived from natural wood, CEF represents the most fundamental unit of cellulose with nanoscale diameter. The preparation of the CEFs involves the modulation of intermolecular hydrogen bonding by the treatment with a proton acceptor and a hydrotropic agent. This elementary deagglomeration of the cellulose fibers increases surface area and anionic charge density, thus promoting uniform dispersion with carbon conductive additives and suppressing interfacial side reactions at electrodes. Consequently, a homogeneous redox reaction is achieved throughout the electrodes. The resulting CEF-based cathode (overlithiated layered oxide (OLO) is chosen as a benchmark electrode active material) exhibits a high areal-mass-loading (50mgcm-2, equivalent to an areal capacity of 12.5mAhcm-2) and a high specific energy density (445.4Whkg-1) of a cell, which far exceeds those of previously reported OLO cathodes. This study highlights the viability of the deagglomerated binder in enabling sustainable high-mass-loading electrodes that are difficult to achieve with conventional synthetic polymer binders.

Hierarchical Interface Enabled by a Guest-Anionic Chemistry for High-Rate Aqueous Zinc-ion Batteries.

The poor reversibility of the zinc anode caused by interfacial side reactions and dendritic growth poses significant constraints on the practical application of aqueous zinc-ion batteries. Herein, a co-solute, acesulfame potassium, with strongly polar, zincophilic guest anions is introduced into a conventional low-concentration aqueous electrolyte. This regulation enhances the electrolyte's ionic conductivity and accelerates the desolvation process of zinc ions at the electrode/electrolyte interface.Furthermore, the introduced acesulfame anions give rise to the formation of a stable solid electrolyte interface with a hierarchical crystalline-amorphous bilayer structure that effectively suppresses side reactions and allows for uniform zinc ion diffusion-deposition. Results show that the zinc anode in the designed electrolyte possesses remarkable reversibility, achieving stable operation under a ultrahigh current density of 40 mA cm-2 and 67.6 % depth of discharge, surpassing most previous reports. Zn//I2 full cells assembled with this electrolyte exhibit high rate capability (135.0 mAh g-1 at 20 A g-1) and remarkable lifespan (96.3% capacity retention after 40,000 cycles at 10 A g-1). A large-sized Zn//I2 pouch cell is also demonstrated, delivering a total capacity of 170 mAh with 78.8% capacity retention after 600 cycles at 3.3 mA cm-2, highlighting the potential of the guest-anionic chemistry in practical applications.

A Robust Dual-Layered Solid Electrolyte Interphase Enabled by Cation Specific Adsorption-Induced Built-In Electrostatic Field for Long-Cycling Solid-State Lithium Metal Batteries.

Solid-state lithium (Li) metal batteries (SSLMBs) are considered as one of the most promising next-generation battery technologies due to their high energy density and intrinsic safety. However, interfacial issues such as side reactions and Li dendrite growth severely hinder the practical application of SSLMBs. In this contribution, we proposed a cationic built-in electrostatic field to drive the generation of an anion-derived dual-layered solid electrolyte interphase (SEI). The specific adsorption of tributylmethyl-phosphonium bis(trifluoromethanesulfonyl)imide (TMPB) cations onto negatively charged Li anode surface significantly prevents interfacial side reactions between vulnerable polyethylene oxide (PEO) and Li metal. More importantly, the formed cationic built-in electrostatic field induces the targeted trapping of Li-salt anions onto the Li metal surface, leading to the generation of an anion-derived dual-layered SEI, composed of a mechanically flexible organic-rich surface layer and a Li-ion conductive inorganic-rich bottom layer. As a result, the Li||Li cell demonstrated an extended lifespan of over 1900 hours with the reduced polarization voltage. The Li||LiFePO4 full cell also exhibited excellent cycling stability, maintaining an average Coulombic efficiency of 99.69% over 200 cycles at 0.5 C. This work provides valuable insights into mitigating interfacial degradation and promoting uniform Li deposition through surface electrostatic field regulation.

Study of the Cathode/Electrolyte Interface in an All-Sulfide-Solid-State Battery Using Lithium-Rich Transition Metal Sulfide.

All-solid-state lithium batteries (ASSBs) are among the most promising energy storage technologies, particularly for electric vehicles, due to their enhanced safety. However, performances of these systems are still hindered by interfacial side reactions at electrode/electrolyte interfaces, especially when sulfide electrolytes are used, and additional issues of mechanical nature. In this work, an ASSB system composed of an argyrodite (Li5.7PS4.7Cl1.3) electrolyte, a lithium-rich sulfide cathode (Li1.2Ti0.8S2) operating at moderate voltage, and a lithium metal anode is investigated. The positive electrode/electrolyte interface is scrutinized during several battery cycles using X-ray photoelectron spectroscopy (XPS) via two complementary approaches (ex situ and in situ). We show that both titanium and sulfur species contribute to the electrochemical process without any detectable degradation of the electrolyte after 20 cycles and without the use of any protective coating. These results suggest that the electrochemical performances of such an all-sulfide system are not limited by the cathode/electrolyte reactivity, opening a promising route for the development of specific cathode materials adapted to sulfide electrolytes.

Undoped ruthenium oxide as a stable catalyst for the acidic oxygen evolution reaction

Reducing green hydrogen production cost is critical for its widespread application. Proton-exchange-membrane water electrolyzers are among the most promising technologies, and significant research has been focused on developing more active, durable, and cost-effective catalysts to replace expensive iridium in the anode. Ruthenium oxide is a leading alternative while its stability is inadequate. While considerable progress has been made in designing doped Ru oxides and composites to improve stability, the uncertainty in true failure mechanism in acidic oxygen evolution reaction inhibits their further optimization. This study reveals that proton participation capability within Ru oxides is a critical factor contributing to their instability, which can induce catalyst pulverization and the collapse of the electrode structure. By restricting proton participation in the bulk phase and stabilizing the reaction interface, we demonstrate that the stability of Ru-oxide anodes can be notably improved, even under a high current density of 4 A cm‒2 for over 100 h. This work provides some insights into designing Ru oxide-based catalysts and anodes for practical water electrolyzer applications.