Anodic Corrosion Research Articles

Simultaneously Regulating Solvation Structure and Interphase by Strong Donor Cosolvent for Stable Zn-Metal Batteries

Aqueous Zn-metal battery has been regarded as the most scalable system for grid-scale energy storage, yet challenges arise from arbitrary dendrite growth and Zn anode corrosion, thus restricting its practical application. Herein, a strong donor cosolvent (hexamethylphosphoramide, HMPA) is introduced to enable highly reversible Zn anode. It is demonstrated that the HMPA can preferentially adsorb on the surface of Zn as well as regulate the solvation structure of Zn2+ by excluding H2O from the solvation sheath and thus weakens the activity of H2O, which contributes to a dense and uniform SEI layer that enables the homogeneous Zn electrodeposition. Owing to the above advantages, the resultant HMPA-containing electrolyte enables highly reversible Zn plating/stripping for thousands of cycles in Zn||Ti and Zn||Zn cells. Consequently, the cycling stability of Zn||V2O5 full cells is also significantly improved with a high capacity of 155 mAh g–1 maintained after 1500 cycles.

A chloride-free electrolyte to suppress the anodic hydrogen evolution corrosion of magnesium anode in aqueous magnesium air batteries

Aqueous magnesium air batteries are promising energy conversion devices because of high theoretical energy density, inherent safety and low cost. However, their practical energy density is significantly limited due to the dramatic hydrogen evolution corrosion of Mg anode in conventional sodium chloride (NaCl) electrolyte. Herein, we suppress the hydrogen evolution reaction on the surface of Mg anode using sodium acetate (NaAc) electrolyte, in which Mg anode exhibits uniform anodic dissolution behavior without the notorious localized corrosion. It is demonstrated that acetate ion (Ac-) averts the localized passive film breakdown of Mg anode in virtue of its large diffusion energy barrier within the film. Therefore, the anodic hydrogen evolution phenomenon amid discharge is evidently repressed. This enables Mg anode to achieve a high utilization efficiency of 84 % at 10 mA cm−2 compared with 59 % in NaCl electrolyte. Mg air battery tests manifest that its specific energy based on the anode weight is boosted from 1370 to 1770 Wh kg−1. Finally, the practicality of NaAc electrolyte is confirmed in a commercial Mg air battery. This work provides a simple and scalable solution for high performance Mg air battery.

Insights into the Corrosion Inhibition Performance of Three 2-Isoxazoline-γ-Lactones for Carbon Steel in Acidic Medium: Linking Molecular and Experimental-Level Information with Microscopic-Scale Modeling

The corrosion inhibition properties of three spiro-isoxazoline derivatives, namely 3,4-diphenyl-1,7-dioxa-2-azaspiro[4.4]non-2-en-6-one (DDA), 3-phenyl-4-(p-tolyl)-1,7-dioxa-2-azaspiro[4.4]non-2-en-6-one (PDA) and 4-(4-methoxyphenyl)-3-phenyl-1,7-dioxa-2-azaspiro[4.4]non-2-en-6-one (MDA) on carbon steel in 1.0 mol/L HCl acid medium were experimentally and computationally investigated. The experimental results showed that the inhibitory efficiency reached remarkable values of 76.26, 80.31, and 82.91%, respectively, for DDA, PDA and MDA at a maximum concentration of 10−3 mol/L. The potentiodynamic polarization curves (PPCs) showed that investigated compounds had a mixed type character, controlling both anodic and cathodic corrosion reactions. In addition, electrochemical impedance spectroscopy (EIS) indicated that the addition of increasing concentration of tested compounds to HCl solutions led to a significant increase in the polarization resistance of the carbon steel, which was accompanied with a simultaneous decrease in the double layer capacitance. On the other hand, the morphological study of the metal surface by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) confirmed the effective protection of the carbon steel by the inhibitors against corrosion through the formation of a protective film on its surface. The adsorption characteristics of investigated compounds on carbon steel were assessed at microscopic level using Density Functional Based Tight Binding (DFTB) simulation, which revealed the formation of covalent bonds between inhibitors’ atoms and Fe atoms. Furthermore, additional insights into the compounds’ reactivity and adsorption configurations on steel surface were obtained from global reactivity descriptors and Monte Carlo simulation. The present work’s outcomes are interesting for further design and performance evaluation of effective organic corrosion inhibitors for acid environments.

Oxygen-permeable and moisture-proof membrane for stable Li-O2/air batteries in humid working environment

The deleterious shuttle of H2O in humid atmosphere causes fatal/irreversible Li-metal anode corrosion and continuous destruction of solid electrolyte interface (SEI) at the Li/electrolyte interface as well as cathode discharge product varies in Lithium-Oxygen/Air batteries (LOBs/LABs), which critically limits their electrochemical performance of LOBs/LABs. Herein, we employ a scalable/flexible polyetetrafluoroethylene@polystylene (PTFE@PS) membrane with excellent oxygen-permeability and moisture-proofing capability to effectively shield Li anode and entire battery systems from H2O corrosion. The stable dual phobicity of PTFE@PS membrane is evidenced by contact angle and penetration experiments, and its ability to block H2O crossover is demonstrated via spectroscopy characterizations of the SEI layer in cycled Li-metal surface. The success of the PTFE@PS membrane has been illustrated by the significantly enhanced cyclability of the Li-metal anodes, depth of full-discharge and cyclability of the LOBs/LABs operated in a humid O2 and practical ambient air atmosphere (RH: 70%). Cycled at limited capacity of 500 mAh/g, the cycle performance of LOBs assembled with PTFE@PS membranes is five times that of that without PTFE@PS membranes. This work reveals how the crossover of H2O damages the Li-metal anode (SEI structure/components) and entire LOBs/LABs, and offers a practically effective approach to improve battery operation stability in humid atmosphere.

Development of High Areal Capacity Electrolytic MnO2–Zn Battery via an Iodine Mediator

The commercialization of electrolytic MnO2–Zn batteries is highly applauded owing to the advantages of cost‐effectiveness, high safety, high energy density, and durable working performance. However, due to the low reversibility of the cathode MnO2/Mn2+ chemistry at high areal capacities and the severe Zn anode corrosion, the practical application of MnO2–Zn batteries is hampered by inadequate lifespan. Leveraging the full advantage of an iodine redox mediator, here we design a highly rechargeable electrolytic MnO2–Zn battery with a high areal capacity. The MnO2–Zn battery coupled with an iodine mediator in a mild electrolyte shows a high discharge voltage of 1.85 V and a robust areal capacity of 10 mAh cm−2 under a substantial discharge current density of 160 mA cm−2. The MnO2/I2–Zn battery with an areal capacity of 10 mAh cm−2 exhibits prolonged stability of over 950 cycles under a high‐capacity retention of ~94%. The scaled‐up MnO2/I2–Zn battery reveals a stable cycle life under a cell capacity of ~600 mAh. Moreover, our constructed MnO2/I2–Zn battery demonstrates a practical energy density of ~37 Wh kg−1 and a competitive energy cost of <18 US$ kWh−1 by taking into account the cathode, anode, and electrolyte. The MnO2/I2–Zn battery, with its remarkable reversibility and reasonable energy density, enlightens a new arena of large‐scale energy storage devices.

Si protected by metal-organic segments as anodes in Si-air batteries

Silicon-air batteries have attracted attention because of their high theoretical energy densities. However, the practical application of Si-air batteries is limited by the corrosion of silicon anodes. In this work, metal-organic segments (MOSs) coating was used for the first time to protect anodes in silicon-air batteries and the effects of MOS coating on the electrochemical performance of silicon-air batteries have been systematically investigated. The surface morphology of Si@MOS composites can be well-controlled by changing solution concentrations. The potentiodynamic polarization curves and the theoretical calculation prove that the corrosion rate of the silicon anodes can be effectively inhibited by the MOS coating. The critical KOH solution concentration can be reduced from 1.9 M for bare silicon to 1.3 M for Si@MOS composite anode. The Si@MOS composite anode also exhibits a longer discharge time of about 430 h at 0.9 V with a specific capacity 114 mAh g−1, which is much higher than that of bare Si (250 h with a specific capacity of 71 mAh g−1). This work not only demonstrates a surface modification method to protect the Si anode, but also provides a novel idea to improve the performance of Si-air batteries.

Corrosion protection studies of different alloys in 1 M HCl by benzimidazole derivative: Combined molecular dynamic simulations/DFT

Corrosion prevention of metals like Steel, Aluminum, and Copper is an interesting problem in industries, to solve this problem corrosion inhibitors are one of the most effective applications for metal protection against corrosion in aggressive media. The effect of (2E)-3-(6-phenylimidazo[2,1-b][1,3]thiazol-5-yl)-1-(2,4,6-trimethylphenyl)prop-2-en- 1-one (KO38) on the protection of steel, aluminum, and copper in 1 M HCl medium was examined using electrochemical polarization tests to assess inhibition efficiency, also scanning electron microscopy (SEM) to analyze the surface of metals. The maximum protection capacity of KO38 by the method of polarization is between 96% and 97% for the three metals exposed in an acid solution containing 10−4 M. The organic inhibitors can be classified as mixed-type inhibitors since they inhibited both anodic corrosion and cathodic corrosion. The study of the dynamic simulation (DM) helped to visualize the energies of adsorption of the molecule (KO38) on the interfaces of Iron (110), Aluminum (111), and Copper (111), the calculations of quantum chemistry were analyzed by (DFT) at B-3LYP /6–311 G (d, p). The experimental results are in good agreement with the theoretical studies.

Complementary combination of lithium protection strategies for robust and longevous lithium metal batteries

A ten-fold higher specific capacity than commercial graphite anodes makes lithium metal anodes extremely attractive for rechargeable battery applications. However, the safety concerns associated with lithium dendrites represent a major barrier to the practical application of lithium metal batteries. Over the past decades, several mechanisms for the growth of lithium dendrites have been proposed from different perspectives. This has led to a variety of strategies to protect the lithium metal anode, such as preparation of artificial solid electrolyte interphase (SEI) and pseudo-liquid anodes. In this review, we present an overview of protection strategies for lithium metal anodes in terms of preventing lithium dendrite growth and regulating lithium deposition behaviours or healing the existing lithium dendrites. Firstly, the mechanisms of dendrite growth and anode corrosion are summarized and compared to better understand the lithium-ion deposition behaviours, which is critical for theoretically guiding the exploration of highly stable lithium anodes. Subsequently, the potential for integrating different strategies is discussed to combine and make full use of the advantages of each strategy, which can facilitate the development of emerging strategies and the improvement of established ones. The availability of the proposed strategies will further narrow the gap between experimental research and the commercial application of rechargeable lithium metal batteries.

Synergistic Effect of Vanadate and Nanoclay Hybrid Inhibitor on the Self-Corrosion and Discharge Activity of Al Anode in Alkaline Aluminum-Air Batteries

The inherent safety and low cost of aqueous aluminum-air (Al-air) batteries have attracted significant attention. However, their lifespan is constrained due to the formation of passive layers and severe self-corrosion of the Al anode. This work addresses the Al anode issues using an innovative design strategy by adding vanadate and nanoclay to modify the interaction of Al and electrolyte. The results have shown that adding each vanadate, nanoclay, and a hybrid combination of both reduced Al anode corrosion considerably. However, the hybrid additive provided the highest inhibition efficiency of 72.6% compared to 57.6% for vanadium and 69.8% for nanoclay. The anode’s anodic efficiency and capacity density reached 81.4% and 2426 mAh.g−1 using a hybrid inhibitor. Electrochemical and microscopical analysis indicated that the corrosion inhibition of the additives was attributed to a protective film formed on the Al anode surface. Therefore, this technique has the potential for application in Al-air batteries to increase their lifespan by increasing the inhibition efficiency of the Al anode.

Suppression of CO2 induced lithium anode corrosion by fluorinated functional group in quasi-solid polymer electrolyte enabling long-cycle and high-safety Li-CO2 batteries

Given high theoretical energy density and environmental-friendly CO2 fixation ability, rechargeable Li-CO2 battery is explored as a promising energy storage device. However, its cycling stability and safety are challenged by the continuous pulverization of Li anode and the leakage of liquid electrolytes (LEs). Herein, a quasi-solid polymer electrolyte (QSPE) with -CF3 functional groups was designed and in-situ fabricated for Li-CO2 battery. The solidification of electrolyte avoids the leakage of LEs and effectively inhibits the diffusion of the acid CO2 and cathode by-products to etch Li anode. Besides, the introduction of -CF3 can construct a fish scale-like LiF-rich solid electrolyte interface on Li anode, which induces the uniform and dense deposition of Li to inhibit the deeper Li from being further etched. The QSPE also exhibits high ion conductivity (1.98×10−3 S cm−1 at 25°C), enhanced Li+ transport number (0.47), and superb stability (>5.27 V vs. Li/Li+). Consequently, the Li-CO2 battery with QSPE delivers effectively suppressed pulverization of Li anode, extraordinary cyclic stability over 295 cycles (1250 h) at 50 μA cm−2, and lower overpotential (1.05 V) compared to the cells with LE. Moreover, the as-prepared QSPE also demonstrates excellent application potential in other Li metal batteries and flexible electronic devices.

Study on Material Design and Corrosion Resistance Based on Multi-Principal Component Alloying Theory.

This study mainly attempts to develop Mg-based alloy materials with excellent corrosion resistance by means of multi-principal alloying. The alloy elements are determined based on the multi-principal alloy elements and the performance requirements of the components of biomaterials. Mg30Zn30Sn30Sr5Bi5 alloy was successfully prepared by vacuum magnetic levitation melting. Through the electrochemical corrosion test with m-SBF solution (pH7.4) as the electrolyte, the corrosion rate of alloy Mg30Zn30Sn30Sr5Bi5 alloy decreased to 20% of pure Mg. It could also be seen from the polarization curve that when the self-corrosion current density is low, the alloy shows superior corrosion resistance. Nevertheless, with the increase in self-corrosion current density, although the anodic corrosion performance of the alloy is obviously better than that of pure Mg, the cathode shows the opposite situation. The Nyquist diagram shows that the self-corrosion potential of the alloy is much higher than that of pure Mg. In general, under the condition of low self-corrosion current density, the alloy materials display excellent corrosion resistance. It is proved that the multi-principal alloying method is of positive significance for improving the corrosion resistance of Mg alloys.

Coupling Hydrazine Oxidation with Seawater Electrolysis for Energy-Saving Hydrogen Production over Bifunctional CoNC Nanoarray Electrocatalysts.

Seawater electrolysis is a promising method to produce H2 without relying on scarce freshwater resource, but its high energy consumption and inevitable accompany of competitive chlorine oxidation reaction (ClOR) are still great technological challenges. Herein, a metal-organic framework(MOF)-templated pyrolysis strategy to prepare uniform cobalt/nitrogen-codoped carbon nanosheet arrays on carbon cloth (CC@CoNC) as highly-efficient but low-cost bifunctional electrocatalysts for hydrazine-assisted seawater electrolysis is explored. The optimized CoNC nanosheet arrays can be used as an efficient bifunctional electrocatalyst to catalyze hydrazine oxidation reaction and hydrogen evolution reaction, remarkably reducing the energy consumption and nicely overcome the undesired anodic corrosion problems caused by ClOR. Impressively, a hydrazine-assisted water electrolysis system is successfully assembled by using the optimized CC@CoNC as both cathode and anode, which only needs an ultra-low cell voltage of 0.557V and an electricity consumption of 1.22kW h per cubic meter of H2 to achieve 200mA cm-2 . Furthermore, the optimized CC@CoNC can also show greatly improved stability in the hydrazine-assisted seawater electrolysis system for H2 production, which can work steadily for above 40h at ≈10mA cm-2 . This study may offer great opportunities for obtaining hydrogen energy from infinite ocean resource by an eco-friendly method.

Coordination Inversion of the Tetrahedrally Coordinated Ru4f Surface Complex on RuO2(100) and Its Decisive Role in the Anodic Corrosion Process

The c(2 × 2) reconstruction of RuO2(100) leads to unusual and flexible surface functionality in the form of a tetrahedrally coordinated Ru4f surface complex with distinct chemical properties that are important for the anodic activity and stability in water electrolysis. We employ first-principles methods based on density functional theory calculations to elucidate the hybridization of this Ru4f surface species and its rich coordination chemistry. Under oxygen evolution reaction (OER) conditions, the consecutive breaking of structural Ru4f–O back bonds is shown to proceed via the back side attack of Ru4f (akin to the Walden inversion) by dissociative water adsorption and the release of two proton/electron pairs. This inversion step of the coordination environment of a surface transition metal cation is considered to be the key step in the anodic dissolution process. Oxygen evolution over Ru4f on RuO2(100)–c(2 × 2) competes with its dissolution. From ab initio thermodynamics, the inherent OER activity over Ru4f is shown to be lower than that of Ru surface sites on the unreconstructed RuO2(100), while the dissolution propensity of the Ru4f surface complex is higher. This finding calls into question the frequently stated hypothesis that higher activity is correlated with a lower stability of the active center.

An Advanced Alkaline Al-Air Fuel Cell Using l-Ascorbic Acid Interface Layer upon Al Anode via Gradient Anti-corrosion

Al metal is considered as an excellent anode material for metal-air fuel cells thanks to the advantages in terms of capacity and energy density. However, the anodic parasitic corrosion has brought great obstacles to the performance breakthrough of Al-air fuel cells. Herein, we innovatively develop an advanced organic interface layer on an Al anode via gradient anti-corrosion, wherein low-cost, nontoxic, and high-ionized l-ascorbic acid is used to modify two basic research systems, 4 M KOH and 4 M KOH electrolyte containing 0.3 M ZnO. The results show that the relative anti-corrosion efficiency of Al and Zn@Al anodes can be gradually enhanced with the increase of l-ascorbic acid concentration. The optimal modification concentration of l-ascorbic acid is 0.35 M. The capacity and anode utilization of the cell increase to 479.50 mAh/g and 16.09% at 20 mA/cm2 after the l-ascorbic acid modification of 4 M KOH, respectively, while an excellent capacity of 2208.39 mAh/g and an anode utilization of 74.09% can be achieved for the cell using an l-ascorbic acid interface layer on a Zn@Al anode at the same current density. The density functional theory reveals that the groups of O–C═C–O and C═O in the layer molecules tend to accept the electrons provided by the Al and Zn@Al surfaces and release more adsorption energy than free H2O. l-ascorbic acid molecules are adsorbed on the anode surface as a stable interface layer, achieving Al self-corrosion inhibition and promoting the sustainable development of Al-air fuel cells.

Highly Stable Garnet Fe2 Mo3 O12 Cathode Boosts the Lithium-Air Battery Performance Featuring a Polyhedral Framework and Cationic Vacancy Concentrated Surface.

Lithium-air batteries (LABs), owing to their ultrahigh theoretical energy density, arerecognized as one of the next-generation energy storage techniques. However, it remains a tricky problem to find highly active cathode catalyst operating within ambient air. In this contribution, a highly active Fe2 Mo3 O12 (FeMoO) garnet cathode catalyst for LABs is reported. The experimental and theoretical analysis demonstrate that the highly stable polyhedral framework, composed of FeO octahedrons and MO tetrahedrons, provides a highly effective air catalytic activity and long-term stability, and meanwhile keeps good structural stability. The FeMoO electrode delivers a cycle life of over 1800h by applying a simple half-sealed condition in ambient air. It is found that surface-rich Fe vacancy can act as an O2 pump to accelerate the catalytic reaction. Furthermore,theFeMoOcatalystexhibitsasuperiorcatalyticcapabilityforthedecompositionofLi2 CO3 .H2 O in the air can be regarded as the main contribution to the anode corrosion andthe deterioration of LAB cells could be attributed to the formation of LiOH·H2 O at the end of cycling. The present work provides in-depth insights to understand the catalytic mechanism in air and constitutes a conceptual breakthrough in catalyst design for efficient cell structure in practical LABs.

The Integration of Biopolymer-Based Materials for Energy Storage Applications: A Review.

Biopolymers are an emerging class of novel materials with diverse applications and properties such as superior sustainability and tunability. Here, applications of biopolymers are described in the context of energy storage devices, namely lithium-based batteries, zinc-based batteries, and capacitors. Current demand for energy storage technologies calls for improved energy density, preserved performance overtime, and more sustainable end-of-life behavior. Lithium-based and zinc-based batteries often face anode corrosion from processes such as dendrite formation. Capacitors typically struggle with achieving functional energy density caused by an inability to efficiently charge and discharge. Both classes of energy storage need to be packaged with sustainable materials due to their potential leakages of toxic metals. In this review paper, recent progress in energy applications is described for biocompatible polymers such as silk, keratin, collagen, chitosan, cellulose, and agarose. Fabrication techniques are described for various components of the battery/capacitors including the electrode, electrolyte, and separators with biopolymers. Of these methods, incorporating the porosity found within various biopolymers is commonly used to maximize ion transport in the electrolyte and prevent dendrite formations in lithium-based, zinc-based batteries, and capacitors. Overall, integrating biopolymers in energy storage solutions poses a promising alternative that can theoretically match traditional energy sources while eliminating harmful consequences to the environment.

Anodic Behavior of Hafnium in Anhydrous Electrodissolution-Coupled Hafnium Alkoxide Synthesis

The electrodissolution-coupled hafnium alkoxide (Hf(OR)4, R is alkyl) synthesis (EHS) system, which has significant environmental and economic advantages over conventional thermal methods, serves as a promising system for green and efficient Hf(OR)4 electro-synthesis. The EHS system is operated based on the simultaneous heterogeneous reactions of hafnium dissolution and ethanol dehydrogenation, as well as the spontaneous solution-based reaction of Hf4+ and OR−. Employing green ethanol and Hf as feedstocks, the anodic hafnium corrosion/dissolution electrochemical behavior of the Et4NCl or Et4NHSO4 based anhydrous system was investigated through electrochemical measurements combined with SEM observations. The results demonstrated that the Et4NCl-based anhydrous ethanol system exhibited an efficient mechanism of passive film pitting corrosion breakdown and metal hafnium dissolution, while the Et4NHSO4-based anhydrous ethanol system reflected the weak corrosion mechanism of the anodic hafnium under the passive film. The polarization resistance of the Et4NCl system was dramatically lower than that of the Et4NHSO4 system, which indicated that the Et4NCl system had superior anodic hafnium corrosion performance compared to the Et4NHSO4 system. Overall, the investigation of the electrochemical behaviors of anodic hafnium corrosion/dissolution provides theoretical guidance for the efficient operation of EHS electrolysis.

Investigation on AC corrosion of aluminum alloy sacrificial anode in the artificial simulated seawater environment

The alternating current (AC) density induced by submarine cables, which are parallel to submarine pipelines, has nonnegligible effects on the sacrificial anode system of submarine pipeline. The objective of this work is to clarify the AC corrosion of aluminum alloy sacrificial anode. The weight loss tests show that the corrosion rate of aluminum alloy increases with the increase in AC density, whereas the corrosion pits are obvious and dense. The calculated AC current efficiency for aluminum alloy is obviously higher than that for carbon steel under the same condition. The analyses of polarization characteristics and local environment reveal that the activity of aluminum alloy increases under the combined action of alloying elements and AC interference. Furthermore, the surface characteristics verify that Al and the alloying elements (Zn or In) in the solid solution with aluminum are oxidized during the anodic half cycles of AC density. And the alkaline environment created by the cathodic reaction in the cathodic half cycles is beneficial to the dissolution of aluminum alloy. In the condition of high AC density, the vigorous gas evolution is observed on coupon surface, resulting in the formation of larger corrosion pits due to the intrinsic effects of the adsorbed hydrogen and hydrogen bubbles. These results provide a guidance to understand the mechanism of AC corrosion for aluminum alloy exposed to artificial simulated seawater environment.

High-Performance Bifunctional Porous Iron-Rich Phosphide/Nickel Nitride Heterostructures for Alkaline Seawater Splitting.

Seawater is the most abundant natural water resource in the world, which is an inexhaustible and low-cost feedstock for hydrogen production by alkaline water electrolysis. It is appearling to develop robust and stable electrocatalysts for alkaline seawater electrolysis. However, the development of seawater electrolysis is seriously impeded by anodic chloride corrosion and chlorine evolution reaction, and few non-noble electrocatalysts show prominent catalytic performance and excellent durability. Here, a heterogeneous electrocatalyst constructed by in situ growing highly dispersed iron-rich bimetallic phosphide nanoparticles on metallic Ni3 N (Fe2-2 x Co2 x P/Ni3 N), which exhibits outstanding bifunctional catalyticactivities for alkaline seawater splitting, is reported. The optimal (Fe0.74 Co0.26 )2 P/Ni3 NandFe2 P/Ni3 N electrocatalysts demand only 113 and 212 mV to afford 100 mA cm-2 for hydrogen and oxygen evolution reactions (HER and OER) in 1 m KOH, respectively, thus substantially expediting overall water/seawater electrolysis at 100 mA cm-2 with 1.592/1.645 V. Particularly, Fe2 P/Ni3 N displays an unprecedented overpotential of 302 mV at 500 mA cm-2 , which represents the best alkaline seawater oxygen evolution activity among the ever-reported non-noble electrocatalysts; and thus substantially expedites overall water/seawater splitting at 500 mA cm-2 with 1.701/1.768 V, surpassing most of the reported non-noble lectrocatalysts. This work provides a new approach for developing high-performance electrocatalysts for seawater splitting.

In Situ Interfacial Passivation in Aqueous Electrolyte for Mg-Air Batteries with High Anode Utilization and Specific Capacity.

Mg-air batteries are a promising new generation of batteries because they can operate in neutral electrolytes that are safe and nontoxic. However, the high corrosion and low utilization of Mg anodes in Mg-air batteries result in low specific capacity and severe self-discharge. In this study, an Mg(OTf)2 -based aqueous electrolyte is developed, which addresses these issues by reducing the contact of the Mg anode with water molecules from the hydrophobic -CF3 groups and forming an MgF2 protective layer. The assembled Mg-air batteries exhibit specific capacities of up to 1920 mAh g-1 Mg (87.32 % utilization based on the Mg anode). In addition, the resting time of the corresponding Mg-air batteries was 123 times longer than that of Mg-air batteries with pure NaCl electrolytes under the same conditions.