Interfacial Reaction Kinetics Research Articles

Interfacial [S─Cu─C] Bonds Induced π-d Electron Coupling Toward Modulating Charge Transfer for Efficient Solar Water Oxidation.

Regulating the interfacial electric field to achieve rapid charge transfer is crucial for superior photoelectrochemical water splitting. Herein, the ultra-thin hydrogen-substituted graphdiyne (HsGDY) is precisely assembled on the surface of CdS nanorod array (Cu-CdS-HsGDY) by an in situ polymerization strategy. The strong π-d electron coupling is aroused by the delocalized π electrons of HsGDY and the delocalized d electrons of CdS through the interfacial [S─Cu─C] bonds. The strong interfacial electric field can effectively promote the charge localization distribution and reduce the charge transfer resistance. The optimized Cu-CdS-HsGDY photoanode obtain a photocurrent density as high as 4.83 mA cm-2 at 1.23 V versus reversible hydrogen electrode in neutral electrolyte solution under AM 1.5G illumination, which is 6.8 times that of the pristine CdS. Moreover, the photoanode maintains an initial photocurrent density of 84% within 4 h without any assistance of sacrificial agents, which is a rather competitive performance of similar sulfide photoanodes. The mechanism of strong π-d electron coupling on interfacial charge transfer and surface reaction kinetics is investigated by transient spectroscopy measurements, density functional theory calculation, and finite element simulation analysis. This work provides new insights into designing a reasonable interface structure to regulate charge transfer for achieve efficient PEC water splitting.

Designable Electrochemiluminescence Patterning for Renewable and Enhanced Bioimaging.

Electrochemical imaging enables an in-depth analysis of the interface heterogeneity and reaction kinetics of single entities. However, electrode passivation during electrochemical reactions decreases the active sites and harms the long-term stability. Here, we introduce a method using laser-induced photothermal effects to restore the electrochemical activity, which is particularly displayed as enhanced micrometric patterns in electrochemiluminescence (ECL) microscopy. By co-localization characterization and X-ray photoelectron spectroscopy, the mechanism of active site regeneration is validated as the removal of the oxide film for restoring the local surface ECL reactivity under laser irradiation. The surface-confined and voltage-dependent features of ECL allows for easy pattern erasure and rewriting, and it shows good reversibility and anti-counterfeiting potential. This approach overcomes the passivation processes, evidently improves the image quality of single biological entities including Shewanella bacteria and cells, and makes the subtle contour structures more distinct. The renewable electrode interface also enhances the ECL signal of model bead-based bioassays. This approach not only showcases precise control in fabricating micron patterns but also holds promise for enhancing the sensitivity in electrochemical immunoassays and bioimaging.

Designable Electrochemiluminescence Patterning for Renewable and Enhanced Bioimaging

Electrochemical imaging enables an in‐depth analysis of the interface heterogeneity and reaction kinetics of single entities. However, electrode passivation during electrochemical reactions decreases the active sites and harms the long‐term stability. Here, we introduce a method using laser‐induced photothermal effects to restore the electrochemical activity, which is particularly displayed as enhanced micrometric patterns in electrochemiluminescence (ECL) microscopy. By co‐localization characterization and X‐ray photoelectron spectroscopy, the mechanism of active site regeneration is validated as the removal of the oxide film for restoring the local surface ECL reactivity under laser irradiation. The surface‐confined and voltage‐dependent features of ECL allows for easy pattern erasure and rewriting, and it shows good reversibility and anti‐counterfeiting potential. This approach overcomes the passivation processes, evidently improves the image quality of single biological entities including Shewanella bacteria and cells, and makes the subtle contour structures more distinct. The renewable electrode interface also enhances the ECL signal of model bead‐based bioassays. This approach not only showcases precise control in fabricating micron patterns but also holds promise for enhancing the sensitivity in electrochemical immunoassays and bioimaging.

Influences of heat flow on corrosion behavior and interfacial reaction kinetics

Heat transfer surface of heat exchange devices often suffers from severe corrosion, and their corrosion behavior is dramatically influenced by both surface temperature and heat flow. In this work, a novel heat transfer interface corrosion testing system was designed and built based on a simulation calculation analysis (COMSOL Multiphysics 6.0 software). By the aid of it, effects of different heat flux on corrosion performance of steel Q235 was investigated through mass loss and electrochemical methods in 0.5 mol/L H2SO4 solution at controlled interface temperatures. Results indicate that variations in concentration and temperature impose a great contribution to corrosion rate but not corrosion mechanism. However, heat flow not only changed the concentration of reactants near the interfacial surface but also affected the rate and kinetic mechanism of corrosion. Positive heat flow could reduce corrosion rate of heat transfer surface, while negative heat flow increased corrosion rate. Heat flow significantly altered parameters of the corrosion reaction rate constant (such as pre-exponential factor, activation energy, entropy change, and enthalpy change), and an approximate exponential relationship between corrosion rate and heat flux was proposed.

Regulation of electron delocalization on porous carbon/manganese-iron oxide for enhancing nonradical processes of sulfamethoxazole: Oxidation pathway and mechanism

Transition metal oxide defect engineering can regulate the electronic properties of materials, thereby realizing nonradical reactions during catalytic processes. In this study, porous carbon/manganese-iron oxide (PC@MFO) composites with different Mn/Fe ratios were prepared via in-situ encapsulation strategy. PC@MFO exhibited superior catalytic degradation and stable recycling performance during peroxymonosulfate (PMS) activation to degrade sulfamethoxazole (SMX). After 10 min of reaction, >92 % of SMX was rapidly degraded, with high selectivity, through oxidative SMX removal from a complex aqueous solution. The kinetics of SMX degradation over different as-prepared samples were also investigated. A recycling study and regeneration treatment revealed no clear deactivation between the 1st and 6th cycles, suggesting that PC@MFO is a reusable heterogeneous catalyst for utilization in efficient oxidative SMX removal. Multiple characterization techniques and density functional theory calculations were used to study the mechanism of SMX degradation process. Nonradical oxidation was found to be the dominant reaction in the catalytic reaction, leading to SMX degradation. This was possibly due to the highly conjugated electron delocalization induced by Mn-Fe in the O-octahedra close to the oxygen vacancies, promoting rapid charge transfer and interfacial reaction kinetics. This study expands the understanding for the activation mechanism driven by Mn-Fe spinel oxides in deep-water treatment.

Interface kinetic manipulation enabling efficient and reliable Mg3Sb2 thermoelectrics

Development of efficient and reliable thermoelectric generators is vital for the sustainable utilization of energy, yet interfacial losses and failures between the thermoelectric materials and the electrodes pose a significant obstacle. Existing approaches typically rely on thermodynamic equilibrium to obtain effective interfacial barrier layers, which underestimates the critical factors of interfacial reaction and diffusion kinetics. Here, we develop a desirable barrier layer by leveraging the distinct chemical reaction activities and diffusion behaviors during sintering and operation. Titanium foil is identified as a suitable barrier layer for Mg3Sb2-based thermoelectric materials due to the creation of a highly reactive ternary MgTiSb metastable phase during sintering, which then transforms to stable binary Ti-Sb alloys during operation. Additionally, titanium foil is advantageous due to its dense structure, affordability, and ease of manufacturing. The interfacial contact resistivity reaches below 5 μΩ·cm2, resulting in a Mg3Sb2-based module efficiency of up to 11% at a temperature difference of 440 K, which exceeds that of most state-of-the-art medium-temperature thermoelectric modules. Furthermore, the robust Ti foil/Mg3(Sb,Bi)2 joints endow Mg3Sb2-based single-legs as well as modules with negligible degradation over long-term thermal cycles, thereby paving the way for efficient and sustainable waste heat recovery applications.

Heterostructure Engineering of Biphase‐Coupled Ternary Transition Metal Phosphoselenide by Topological Transformation Enabling High Performance for Supercapacitors

AbstractThe exploration of promising electrode materials with structural stability and rapid interfacial reaction kinetics is highly desirable for supercapacitors toward large‐scale applications. Herein, the synthesis of biphase‐coupled CoPSe/NiP0.24Se1.76 with multiple in‐plane heterointerfaces using the in situ topological transformation approach is presented. As a novel ternary metal phosphoselenide (TMPSe) for supercapacitor cathode that is fabricated by synchronous phosphoselenization strategy, it realizes a superior lifespan with cycling compared to conventional transition metal selenides. The depleted anti‐bonding eg* orbitals of transition metal ions (Co/Ni) in the CoPSe/NiP0.24Se1.76, as proved by preliminary theoretical calculations, strengthens the chemical bonding between Co/Ni and coordinating atoms, thereby enhancing the chemical stability. Simultaneously, the CoPSe/NiP0.24Se1.76 in‐plane multi‐heterostructures can not only alleviate the volume change during the charge–discharge process but also expose more active sites, promoting the adsorption of OH− ions, which is conducive to the rapid redox reaction kinetics of the CoPSe/NiP0.24Se1.76, and consequently, it delivers a remarkable reversible capacity and excellent long‐term cycle stability with 97.7% initial capacitance retention over 16 000 cycles. Moreover, the asymmetric supercapacitors with this cathode demonstrate outstanding rate capability and high energy density. This strategy of constructing biphase‐coupled CoPSe/NiP0.24Se1.76 by topological transformation is of great potential application for the high‐performance electrode material.

Role of Oxide-Derived Cu on the Initial Elementary Reaction Intermediate During Catalytic CO2 Reduction.

The catalytic role of oxide-derived Cu (OD-Cu) in promoting CO2 reduction (CO2R) to C2+ products has been appreciated for decades. However, the dynamic evolution of the surface oxidation states, together with their real correlation to the binding of reaction intermediates, remains unclear due to technical challenges. Here, we show the time-resolved spectroscopic signatures of key OD-Cu-CO2•- intermediates during catalytic CO2 reduction through one electron transfer from nanoseconds to seconds time scale. We generated the initial intermediate CO2•- radicals in the bulk solution and monitored the interfacial reaction kinetics with well-defined OD-Cu (Cu(0), Cu(I), and Cu(II)) nanoparticles. Combined with molecular simulations, transient absorption profiles analysis reveals that Cu(I) induced a faster CO2•- radical coupling reaction than Cu(0), whereas Cu(II) is only reduced to Cu(I) by the CO2•- radical. Furthermore, the newly developed multistep cumulative pulse methodology uncovered the transition in chemical states of mixed OD-Cu during radical coupling reactions. This pulse radiolysis study provides compelling evidence for the beneficial role of subsurface oxides in early time catalytic CO2 transformation.

Phase Reconstruction‐Directed Synthesis of Oxalate‐Functionalized Nickel Hydroxide Electrocatalyst for High‐Yield H2O2 Generation at Industrial Currents

AbstractThe electrochemical oxygen reduction reaction (2e− ORR) offers a promising approach for H2O2 production, yet developing highly active, selective, and stable electrocatalysts remains a challenge. In this work, a phase reconstruction strategy is presented to synthesize an oxalate‐adsorbed nickel hydroxide electrocatalyst (Ni(OH)2‐C2O4) through the self‐dissociation of nickel oxalate in an alkaline medium, leading to a notable enhancement in H2O2 yield at elevated current densities. Remarkably, Ni(OH)2‐C2O4 exhibits a 2e− selectivity exceeding 93% across a broad voltage range (0.0 to 0.5 V vs RHE) in 0.1 M KOH, outperforming pristine Ni(OH)2. When deployed as a gas diffusion electrode in a flow cell, the Ni(OH)2‐C2O4 catalyst demonstrates stable operation for 50 h at 200 mA cm−2, with a Faradaic efficiency surpassing 90% and a peak H2O2 yield of 6.2 mol g−1cat h−1. Comprehensive advanced characterizations, including in situ Raman spectroscopy, transient photovoltage spectra, and transient potential scanning spectra, coupled with post‐ORR analyses, reveal that surface‐adsorbed oxalate groups on Ni(OH)2 enhance the interfacial reaction kinetics between active Ni sites and reactants by inducing a charge trapping effect and forming a hydrogen‐bonded network, facilitating robust and high‐yield H2O2 production.

Recent Research on the Optimization of Interfacial Structure and Interfacial Interaction Mechanisms of Metal Matrix Composites: A Review

Interfaces in metal matrix composites (MMCs) are crucial in determining the mechanical properties and functionality of MMCs. This article reviews recent scientific advances and issues related to MMC interfaces from four different perspectives: interfacial structural design, interfacial defect control, thermodynamics and kinetics of interfacial reactions, and interfacial microstructure properties‐based numerical simulation. The influence of interfacial microstructural features on interfacial strength–toughness trade‐offs and their functionality is given special attention. The interfacial problem is still one of the main challenges to be solved in the composite system, which is mainly reflected in the following aspects: interfacial microstructure–deformation mechanisms in complex systems, precise control of interfacial defects and interfacial reaction products, and the efficient and cost‐effective application of numerical simulation techniques. The integrated computation and intelligent design (artificial intelligence) of composites through multiscale computational simulation with the guidance of “interface design‐property prediction” will be the key area of MMC interface research in the future.

A Kinetic Model for Oxide–Carbonitride Inclusion Heterogeneous Nucleation and Precipitation during Superalloy Solidification

Complex oxide–carbonitrides (MgO-Ti(CN), Al2O3-Ti(CN), and MgO·Al2O3-Ti(CN)) are the most common non-metallic inclusions presented in cast and wrought superalloys. In this work, a coupled kinetics model was proposed to predict the complex oxide–carbonitride inclusion’s precipitation behavior during the solidification of superalloys. This model takes into account thermodynamics, micro-segregation, heterogeneous nucleation in the inter-dendritic liquid, and growth controlled by the diffusion of solute elements and kinetics of interfacial reaction. The results demonstrated that both the cooling rate and nitrogen content take significant effects on the final size of complex oxide–carbonitride inclusions, as the former controls the total growth time and the latter determines the initial precipitation temperature. In comparison, the particle size of primary oxides shows a negligible impact on the final size of complex inclusions. The practice of an industrial vacuum arc remelting confirmed that the inclusion size variation predicted by the present model is reasonably consistent with the experimental results.

Direct mechanochemical synthesis of nano-LiAlH4 promoted by 0.696 wt% TiCl4 catalyst surface-modified Al powder

LiAlH4, known for its high hydrogen capacity and metastable nature, is a promising hydrogen source under mild conditions. However, its reversible regeneration from stable binary dehydrogenation phases (LiH/Al) is thermodynamically and kinetically hindered. By constructing a homogeneous and highly dispersed molecular layer of TiCl4 on the surface of the Al reactant to enhance the kinetics of the multiphase interfacial reaction, we achieved the direct mechanochemical synthesis of nano-LiAlH4, bypassing the intermediate phase Li3AlH6. Using the strong Lewis acidity of Ti4+, TiCl4 was chemically adsorbed onto the surface of the Al powder through Ti-O-Al bonds, with a loading capacity of only 0.696 wt%. The obtained TiCl4 surface-modified Al powder and LiH were hydrogenated by ball milling for 10 h under hydrogen pressure to synthesize nano-LiAlH4, which was then dehydrogenated at room temperature. This indicates that the crucial effects of the catalytic sites were dispersed on the reactant surface to ensure the local environment of the multiphase absorption/desorption hydrogen reaction interface and promote the reaction kinetics.

Interfacial characteristics and thermal stability of polymer-derived SiCf/Ti composite fabricated by powder hot isostatic pressing

The novel SiCf/Ti composite is prepared by hot isostatic pressing (HIP) with polymer-derived (PD) SiC fiber and powder titanium alloy as raw materials in this work. The interfacial characteristics and thermal stability of the PD SiCf/Ti composite have been systematically investigated. The interfacial properties of the PD SiCf/Ti composites are quantified to discuss the interfacial reaction mechanisms and kinetics. The results show that with the proposed HIP process, the powder matrix can be near-fully dense, and the matrix and SiC fiber are well bonded with a uniform interfacial layer. The major interfacial products are C-Ti compounds and Si-Ti compounds, which are formed by atomic diffusion reaction. During subsequent thermal exposure conditions, the interfacial layer growth is temperature-dependent and diffusion-controlled, following the parabolic relation and Arrhenius law. The frequency factor k0 is 102–103 times lower than that in the chemical vapor deposition (CVD) SiCf/Ti composites, showing better interfacial thermal stability. After thermal exposure, the element diffusion becomes significant, and the microhardness of the near-interface zone is noticeably greater than the matrix microhardness because of the atomic diffusion of C. The microhardness of both the matrix and near-interface zone reaches the highest value after 900 °C/9 h thermal exposure. It is concluded that the PD SiCf/Ti composites with good thermal stability can be successfully fabricated by powder HIP.

Synthesis of carbon dots with tailored heteroatomic structure for achieving ultrahigh effectiveness in persulfate activation

Carbon dots (CDs) are normally feature with zero-dimensional structure, excellent solubility, good biosafety, and exceptional photoelectronic properties, thus, awakening the homogeneous-like photocatalytic potency of CDs in peroxymonosulfate (PMS) activation can afford new idea for water body remediation. Herein, we presented a facile nitrogen and sulfur co-doping strategy for the development of high-performance CDs-based photocatalysts. Through the deep investigation on the structure-activity relationship, we proposed that the incorporated pyridinic N within CDs structure could serve as efficient Lewis basic sites for PMS confinement. Importantly, the co-existence of oxidized sulfur groups and specific nitrogen speciation (pyridine N and pyrrolic N) induced unique “push-pull” effect on the photogenerated carriers within the surface state of S,N co-doped CDs. The unique synergy sites and surface hydrophilic nature conferred the CDs exceptional photocatalytic effectiveness, presenting a remarkable PMS consumption ratio of 7.62 per gram of the CDs photocatalyst within just 20 min. Profited from the improved kinetics of interfacial reactions, the CDs-photocatalyzed oxidation system that consisted largely of sulfate radicals can completely degrade rhodamine B within 12.5 min, and hold great potential in long-term operation without needing to regenerate CDs catalyst.

Thermodynamics and kinetics of cation partitioning between plagioclase and trachybasaltic melt in static and dynamic systems: A reassessment of the lattice strain and electrostatic energies of substitution

Most of the solidification history of magmas beneath active volcanoes takes place in chemically and physically perturbed plumbing systems where the growth of crystals is collectively governed by a range of kinetic processes related to the dynamics of crustal reservoirs and eruptive conduits. In this context, we have experimentally investigated the partitioning of major, minor, and trace cations between plagioclase and trachybasaltic melt under conventional static (no physical perturbation) and dynamic (melt stirring) crystallization regimes. Slow interface reaction kinetics are established between the advancing crystal surface and the adjacent melt, as the result of the combined control of a small degree of effective undercooling, prolonged diffusive relaxation, and convective homogenization. The kinetic aspects of plagioclase growth influence the partitioning of trace cations during transport of structural units across the crystal-melt interface, with consequent departure from macroscopic equilibrium in the system. The type and number of charge–balanced and −imbalanced configurations produced by the accommodation of trace cations into the coordination polyhedron can be thermodynamically rationalized in terms of lattice strain and electrostatic partitioning energetics. However, the overall solution energy accompanying trace cation kinetic substitutions cannot be entirely deconvoluted from major component activities in both melt and plagioclase phases. The emerging view that slow interface kinetic processes may lead to strong compositional dependence for the partition coefficient in dynamic subvolcanic environments contrasts markedly with the conventional idea that the energetics of cation partitioning are dominantly controlled by the effect of isothermal changes in the bulk system.

Enhanced Li-ion battery performance based on multisite oxygen vacancies in WO3-x@rGO negative electrode

While transition-metal oxides have emerged as promising candidates for lithium energy storage, several issues are remained to be addressed such as low conductivity, rate performance, and recyclability. In this study, a three-dimensional interconnected sheet-like heterostructure of WO3-x coated with reduced graphene oxide (rGO) was synthesized using the hydrothermal method. This structure significantly enhanced the conductivity of WO3-x. By combining the heterojunction with oxygen vacancies (OV), the active sites are enlarged, promoting the effective movement of ions and electrons at the interface between the WO3-x and rGO. The prepared anode exhibits a high specific capacity of 1202.6 mAh/g at 0.1 A g−1, with a cycling retention rate of 96 % after 100 cycles. Meanwhile, even at 5 A g−1, it still maintains a capacity of 305 mAh/g after 500 cycles. Theoretical calculations reveal that the presence of the composite heterogeneous structure enables WO3-x@rGO to possess appropriate adsorption energy, lower work function, and reduced barriers. This arrangement provides abundant active sites, promoting the rapid penetration of the electrolyte and enhancing the interface reaction kinetics, which is consistent with the experimental results. This study offers a new strategy for Li-ion anode materials.

Inorganic/organic hybrid interfacial internal electric field modulated charge separation of resorcinol-formaldehyde resin for boosting photocatalytic H2O2 production

The strategy of inorganic/organic semiconductor material hybridization is of great significance for the development of highly active photocatalysts. Resorcinol-formaldehyde (RF) resin with a special donor-acceptor (D-A) structure shows excellent performance in the photocatalytic production of H2O2. However, the lack of an internal driving force for the separation and transfer of photogenerated electrons and holes in RF resin greatly limits the performance of H2O2 production. Herein, an inorganic/organic hybrid core-shell structure ZnS@RF photocatalyst was prepared by directionally induced coating of RF resin shells of different thicknesses on the surface of monodisperse ZnS nanospheres. Consequently, the photocatalytic H2O2 performance of ZnS@RF with the optimal RF resin shell thickness reaches 367.9 μmol L−1, which is 69 and 2 times that of ZnS and HRF, respectively. Density functional theory (DFT) calculations and related characterization results collectively demonstrate that the excellent photocatalytic H2O2 production performance of ZnS@RF photocatalyst is mainly attributed to the internal electric field (IEF) formed at the hybrid interface of ZnS and RF heterojunction and the optimization of RF shell thickness, which significantly enhances the separation and transfer of photogenerated carriers and modulates the interfacial catalytic reaction kinetics. This work opens up an avenue for designing inorganic/organic hybrid heterojunction photocatalyst materials with excellent photocatalytic activity.

MoS2/SnS heterostructure composite for high-performance lithium-ion battery anodes

Layered metal sulfides are potential anode materials for lithium-ion batteries (LIBs) because their unique structure makes them suitable for Li+ de-intercalation. As a typical 2D layered material, MoS2 is a potential anode material for LIBs due to the weak van der Waals forces between the layers, which facilitates the de-intercalation of Li+ and supports multiple Li+. However, when MoS2 is used as anodes for LIBs material, rapid capacity decay hinders the application. Coupling two different materials to form a heterogeneous structure is an effective way to solve the above problems. In this work, one-pot hydrothermal method is proposed to construct MoS2/SnS heterostructure composites. The electrochemical properties are significantly enhanced, which could be attributed to the presence of heterogeneous structures, leading to increase the electrode charge transfer rate and interfacial reaction kinetics. The results show that the discharge capacity of the MoS2/SnS-1.5 electrode is about 1492.1 mAh/g at 500 mA/g. Furthermore, assembled MoS2@SnS-1.5||LiCoO2 full cell displays a high discharge capacity of 226.1 mAh/g after 50 cycles at 500 mA/g. This facile method provides the application value of layered metal sulfides as LIBs anode materials.

Exploring the Relationship between Interfacial Chemistry and Thermal Safety of a Flame Retarding Semisolid Electrolyte

The safety-related performance of LIBs still remains as a major issue even after more than three decades of commercialization.1 When typical electrolytes composed of flammable organic liquid solvents vaporize and decompose exothermically during thermal runaway, they pose serious risk to human health and infrastructure.2 Conventional lithium-ion batteries (LIBs) are energy storage devices which function as electrochemical systems subject to highly dynamic heterogeneous reaction phenomena. As a result, the tolerance levels of tangible harm to users and surrounding environments may be amplified considerably as scale and pervasiveness of technology increases. Beyond consumer devices, large-scale energy storage to complement renewable power generation technologies is instrumental to the goal of decarbonization via electrification and thus global goals for carbon neutrality in the 21st century. Renewable power generation benefits substantially from decoupling the spatial and temporal points of energy generation from that of demand.Recent efforts in academia and industry alike have endeavored to replace volatile and flammable conventional liquid electrolytes (composed of classes of compounds such as carbonates or ethers) with intrinsically nonflammable liquid electrolytes (composed of fluorinated and phosphorus-containing organic solvents).3–5 Simultaneously, solid-state electrolytes have been touted as an avenue to not only wholly replace the liquid component of the cell to improve safety, but also as a higher-energy density next-generation battery electrolyte.6 However, these strategies are often examined as materials-level design choices for improving “built-in” safety and not as changes to a dynamic and multiscale electrochemical system.In this study, we find that the intrinsic safety of a system is highly dependent on the interfacial degradation pathways of the electrode-electrolyte configuration, which acts as a direct complement to the thermal behavior which may result in thermal runaway. Through detailed multimodal calorimetry and characterization of the interfacial composition, this work subsequently brings the question of flammability into focus as a downstream consequence of the interfacial reaction kinetics. This is accomplished through the combined efforts of thermal analyses as well as X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy accompanied with electron crystallography analyses, and nuclear magnetic resonance studies of the ionic transport behavior through the polymeric electrolyte. Through these efforts, design principles centered around holistic assessment of the lifespan of materials and their electrochemical and thermal interactions are developed towards the greater goal of improving the safety and resilience of LIBs and their devices against the wide spectrum of abuse scenarios created by their expanding application space.(1) Feng, X.; Ren, D.; He, X.; Ouyang, M. Mitigating Thermal Runaway of Lithium-Ion Batteries. Joule 2020, 4 (4), 743–770. https://doi.org/10.1016/j.joule.2020.02.010.(2) Wang, Q.; Jiang, L.; Yu, Y.; Sun, J. Progress of Enhancing the Safety of Lithium Ion Battery from the Electrolyte Aspect. Nano Energy 2019, 55, 93–114. https://doi.org/10.1016/j.nanoen.2018.10.035.(3) Cao, X.; Xu, Y.; Zhang, L.; Engelhard, M. H.; Zhong, L.; Ren, X.; Jia, H.; Liu, B.; Niu, C.; Matthews, B. E.; Wu, H.; Arey, B. W.; Wang, C.; Zhang, J.-G.; Xu, W. Nonflammable Electrolytes for Lithium Ion Batteries Enabled by Ultraconformal Passivation Interphases. ACS Energy Letters 2019. https://doi.org/10.1021/acsenergylett.9b01926.(4) Wang, J.; Yamada, Y.; Sodeyama, K.; Watanabe, E.; Takada, K.; Tateyama, Y.; Yamada, A. Fire-Extinguishing Organic Electrolytes for Safe Batteries. Nat Energy 2018, 3 (1), 22–29. https://doi.org/10.1038/s41560-017-0033-8.(5) Zheng, Q.; Yamada, Y.; Shang, R.; Ko, S.; Lee, Y.-Y.; Kim, K.; Nakamura, E.; Yamada, A. A Cyclic Phosphate-Based Battery Electrolyte for High Voltage and Safe Operation. Nat Energy 2020, 5 (4), 291–298. https://doi.org/10.1038/s41560-020-0567-z.(6) Janek, J.; Zeier, W. G. A Solid Future for Battery Development. Nat Energy 2016, 1 (9), 1–4. https://doi.org/10.1038/nenergy.2016.141

Microstructural evolution and corrosion behavior of deformed GH3536 alloy fabricated by laser metal deposition for bipolar plates in PEMFC

The influences of cold rolling deformation on the microstructures and corrosion behavior of laser metal deposition processed GH3536 alloy were investigated through electron backscattered diffraction and electrochemical tests. The results indicate that the deformed sample within a 15 % of reduction exhibits an excellent corrosion resistance in the simulated PEMFC solution, which can be mainly attributed to a small amount of deformation providing more nucleation sites for Cr to form compact Cr2O3 passive films. In addition, an appropriate compressive residual stress reduces point defect concentrations in passive films and limits interfacial reaction kinetics. In comparison, the corrosion resistance of GH3536 alloy obviously decreases with an increase in deformation reduction from 15 % to 50 %. Apart from a strong increase in activation energy, high-density dislocations after a severe deformation will enhance the surface activity and result in the lattice distortion in the passive film, which deteriorates the corrosion resistance of cold-rolled GH3536 alloy samples.