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Abstract Aqueous zinc-ion batteries, in terms of integration with high safety, environmental benignity, and low cost, have attracted much attention for powering electronic devices and storage systems. However, the interface instability issues at the Zn anode caused by detrimental side reactions such as dendrite growth, hydrogen evolution, and metal corrosion at the solid (anode)/liquid (electrolyte) interface impede their practical applications in the fields requiring long-term performance persistence. Despite the rapid progress in suppressing the side reactions at the materials interface, the mechanism of ion storage and dendrite formation in practical aqueous zinc-ion batteries with dual-cation aqueous electrolytes is still unclear. Herein, we design an interface material consisting of forest-like three-dimensional zinc-copper alloy with engineered surfaces to explore the Zn plating/stripping mode in dual-cation electrolytes. The three-dimensional nanostructured surface of zinc-copper alloy is demonstrated to be in favor of effectively regulating the reaction kinetics of Zn plating/stripping processes. The developed interface materials suppress the dendrite growth on the anode surface towards high-performance persistent aqueous zinc-ion batteries in the aqueous electrolytes containing single and dual cations. This work remarkably enhances the fundamental understanding of dual-cation intercalation chemistry in aqueous electrochemical systems and provides a guide for exploring high-performance aqueous zinc-ion batteries and beyond. 

Abstract Oxygen reduction reaction (ORR) is an electrochemical reaction in which dissolved oxygen in an electrolyte is reduced to OH⁻/H₂O when receiving electrons. This reaction plays a crucial role in shaping the efficiency of both metal–air batteries and fuel cells, and precious metals are the dominant catalysts carrying out the ORR in their cathodes. However, how to manipulate the electronic structure of precious metals as active sites to further promote ORR performance and maximize the utilization rate is still under development. Metal oxide serves as suitable and promising support that can strongly interact with precious metals for both activity and durability enhancement. Herein, we present recent research updates on strong precious metal–metal oxide interaction (SPMMOI) utilized in ORR. We start by introducing the background of ORR, the issues to be solved, and its practical applications followed by a thorough discussion of the reaction mechanism and comprehensive evaluation protocols of performance. We then provide a complete understanding of the working principle of SPMMOI and highlight the related advances. Finally, we summarize the merits of the precious metal–metal oxide system and propose the research direction as well as some urgent problems to be addressed in the future. 

Abstract Metal anode instability, including dendrite growth, metal corrosion, and hetero-ions interference, occurring at the electrolyte/electrode interface of aqueous batteries, are among the most critical issues hindering their widespread use in energy storage. Herein, a universal strategy is proposed to overcome the anode instability issues by rationally designing alloyed materials, using Zn-M alloys as model systems (M = Mn and other transition metals). An in-situ optical visualization coupled with finite element analysis is utilized to mimic actual electrochemical environments analogous to the actual aqueous batteries and analyze the complex electrochemical behaviors. The Zn-Mn alloy anodes achieved stability over thousands of cycles even under harsh electrochemical conditions, including testing in seawater-based aqueous electrolytes and using a high current density of 80 mA cm⁻². The proposed design strategy and the in-situ visualization protocol for the observation of dendrite growth set up a new milestone in developing durable electrodes for aqueous batteries and beyond. 

Abstract Uncontrollable dendrite growth is closely related to non‐uniform reaction environments. However, there is a lack of understanding and analysis methods to probe the localized electrochemical environment (LEE). Here the effects of the LEE are investigated, including localized ion concentrations, current density, and electric potential, on metal plating/stripping dynamics and dendrite minimization. A novel in situ 3D microscopy technique is developed to image the morphology dynamics and deposition rate of Zn plating/stripping processes on 3D Zn–Mn anodes. Using the in situ 3D microscope, the electrode morphology changes during the reactions are directly imaged and Zn deposition rate maps at different time points are obtained. It is found that reaction kinetics are highly correlated to LEE and electrode morphology. To further quantify the LEE effects, the digital twin technique is employed that allows the accurate calculation of the electrochemical environments, such as localized ion concentrations, current density, and electric potential, which cannot be directly measured from experiments. It is found that the curvature of the 3D electrode surface determines the LEE and significantly influences reaction kinetics. This provides a new strategy to minimize the dendrite formation by designing and optimizing the 3D geometry of the electrode to control the LEE. 

Abstract To produce efficient ORR catalysts with low Pt content, PtNi porous films (PFs) with sufficiently exposed Pt active sites were designed by an approach combining electrochemical bottom‐up (electrodeposition) and top‐down (anodization) processes. The dynamic oxygen‐bubble template (DOBT) programmably controlled by a square‐wave potential was used to tune the catalyst morphology and expose Pt active facets in PtNi PFs. Surface‐bounded species, such as hydroxyl (OH^*, *=surface site) on the exposed PtNi PFs surfaces were adjusted by the applied anodic voltage, further affecting the dynamic oxygen (O₂) bubbles adsorption on Pt. As a result, PtNi PF with enriched Pt(111) facets (denoted as Pt_3.5 %Ni PF) was obtained, showing prominent ORR activity with an onset potential of 0.92 V (vs. RHE) at an ultra‐low Pt loading (0.015 mg cm⁻²). 

Abstract The Zn‐air battery (ZAB) is attracting increasing attention due to its high safety and preeminent performance. However, the practical application of ZAB relies heavily on developing durable support materials to replace conventional carbon supports which have unrecoverable corrosion issues, severely jeopardizing ZAB performance. Herein, a novel porous FeCo glassy alloy is developed as a bifunctional catalytic support for ZAB. The conducting skeleton of the porous glassy alloy is used to stabilize oxygen reduction cocatalysts, and more importantly, the FeCo serves as the primary phase for oxygen evolution. To demonstrate the concept of catalytic glassy alloy support, ultrasmall Pd nanoparticles are anchored, as oxygen reduction active sites, on the porous FeCo (noted as Pd/FeCo) for ZAB. The Pd/FeCo exhibits a significantly improved electrocatalytic activity for oxygen reduction (a half‐wave potential of 0.85 V) and oxygen evolution (a potential of 1.55 V to reach 10 mA cm⁻²) in the alkaline media. When used in the ZAB, the Pd/FeCo delivers an output power density of 117 mW cm⁻²and outstanding cycling stability for over 200 h (400 cycles), surpassing the conventional carbon‐supported Pt/C+IrO₂catalysts. Such an integrated design that combines highly active components with a porous architecture provides a new strategy to develop novel nanostructured electrocatalysts. 

Abstract Electrode stabilization by surface passivation has been explored as the most crucial step to develop long‐cycle lithium‐ion batteries (LIBs). In this work, functionally graded materials consisting of “conversion‐type” iron‐doped nickel oxyfluoride (NiFeOF) cathode covered with a homologous passivation layer (HPL) are rationally designed for long‐cycle LIBs. The compact and fluorine‐rich HPL plays dual roles in suppressing the volume change of NiFeOF porous cathode and minimizing the dissolution of transition metals during LIBs cycling by forming a structure/composition gradient. The structure and composition of HPL reconstructs during lithiation/delithiation, buffering the volume change and trapping the dissolved transition metals. As a result, a high capacity of 175 mAh g⁻¹(equal to an outstanding volumetric capacity of 936 Ah L⁻¹) with a greatly reduced capacity decay rate of 0.012% per cycle for 1000 cycles is achieved, which is superior to the NiFeOF porous film without HPL and commercially available NiF₂‐FeF₃powders. The proposed chemical and structure reconstruction mechanism of HPL opens a new avenue for the novel materials development for long‐cycle LIBs. 

Abstract A crucial step toward clean hydrogen (H₂) energy production through water electrolysis is to develop high‐stability catalysts, which can be reliably used at high current densities for a long time. So far, platinum group metals (PGM) and their oxides, for example, Pt and iridium oxide (IrO₂) have been well‐regarded as the criterion for hydrogen and oxygen evolution reactions (HER and OER) electrocatalysts. However, the PGM catalysts usually undergo severe performance decay during the long‐term operation. Herein, the in situ growth of iron phosphosulfate (Fe₂P₂S₆) nanocrystals (NCs) catalysts on carbon paper synthesized by combing chemical vapor deposition with solvent‐thermal treatment is reported to show competitive performance and stability as compared to the state‐of‐the‐art PGM catalysts in a real water electrolyzer. A current density of 370 mA cm⁻²is achieved at 1.8 V when using Fe₂P₂S₆NCs as bifunctional catalysts in an anion exchange membrane water electrolyzer. The Fe₂P₂S₆NCs also show much better stability than the Pt‐IrO₂catalysts at 300 mA cm⁻²for a continuous 24 h test. The surface generated FeOOH on Fe₂P₂S₆is the real active site for OER. These results indicate that the Fe₂P₂S₆NCs potentially can be used to replace PGM catalysts for practical water electrolyzers. 

This review revisits critical descriptors to assess the performance of Zn–air batteries. The recent progress of inorganic nanoporous metal films as self-standing air electrodesfor Zn–air batteries is systematically summarized and analyzed.