The MgF 2 and F-terminated groups effectively infiltrated the ion transport channels within UiO-66, thereby regulating the desolvation process and facilitating rapid Li + transport kinetics.

Abstract Proton‐conducting polymer electrolyte membrane water electrolysis (PEMWE) is a promising technology for generating clean and sustainable hydrogen fuels from water. However, PEMWE requires the use of expensive electrocatalysts; the currently available electrocatalysts for the oxygen evolution reaction (OER) depend on noble metals (Ir, Ru). Since noble metals are expensive, commercialization of PEMWE remains elusive. In addition, PEMWE suffers from the very slow kinetics of the OER in acidic media. Thus, the development of noble‐metal‐reduced, highly active, and acid‐compatible oxygen evolution electrocatalysts is needed for the commercialization of PEMWE to be viable. In this regard, perovskite oxides have great potential for application as OER electrocatalysts in acidic media, because their multimetal‐oxide forms can reduce the use of noble metals, and their high structural and compositional flexibility can modulate the electronic structure and OER activity. In this review, current knowledge regarding state‐of‐the‐art perovskite oxides for acidic water oxidation electrocatalysts is summarized. First, the fundamental OER mechanism of electrocatalysts in acidic media is introduced briefly. Second, Ir‐ and Ru‐based perovskite oxides in acidic solutions are provided, focusing on their stability and OER activity. Finally, some challenges facing the development of perovskite oxide‐based electrocatalysts, and a perspective on their future are discussed.

Abstract Hybridized 1D/2D CuGeO 3 /graphene composites are applied as the oxygen–electrode electrocatalysts for Li–O 2 batteries. The CuGeO 3 /graphene composites are synthesized by the crystallographic alignment of CuGeO 3 nanowires on graphene, rendering strong heteroepitaxial coupling between the 1D oxide nanostructures and the 2D electrically conducting graphene. The inherited excellent electrocatalytic activity of the CuGeO 3 /graphene composites leads to lower overpotentials and more stable cycling performance of Li–O 2 cells than CuGeO 3 nanowires and graphene. The relationships between CuGeO 3 nanowires and graphene are studied for the oxygen reduction and oxygen evolution activity in both aqueous and nonaqueous solutions, and the electrocatalytic activity is improved by manipulating the redox pair and sp3/sp2 via surface chemical modification.

In article number 1802319, by Dong-Wan Kim and co-workers, unique 3D architectures of quaternary (Co1−xNix)(S1−yPy)2/Graphene hybrids are developed as high-performance bifunctional electrocatalysts for overall water splitting. By structural and compositional engineering, doughnut-like shaped 3-dimensional architectures of (Co1−xNix)(S1−yPy)2/Graphene are successfully synthesized. (Co1−xNix)(S1−yPy)2/Graphene achieves excellent electrocatalytic hydrogen and oxygen evolution reaction performance as a bifunctional electrocatalyst for overall water splitting.

The MgF 2 and F-terminated groups effectively infiltrated the ion transport channels within UiO-66, thereby regulating the desolvation process and facilitating rapid Li + transport kinetics.

Abstract Proton‐conducting polymer electrolyte membrane water electrolysis (PEMWE) is a promising technology for generating clean and sustainable hydrogen fuels from water. However, PEMWE requires the use of expensive electrocatalysts; the currently available electrocatalysts for the oxygen evolution reaction (OER) depend on noble metals (Ir, Ru). Since noble metals are expensive, commercialization of PEMWE remains elusive. In addition, PEMWE suffers from the very slow kinetics of the OER in acidic media. Thus, the development of noble‐metal‐reduced, highly active, and acid‐compatible oxygen evolution electrocatalysts is needed for the commercialization of PEMWE to be viable. In this regard, perovskite oxides have great potential for application as OER electrocatalysts in acidic media, because their multimetal‐oxide forms can reduce the use of noble metals, and their high structural and compositional flexibility can modulate the electronic structure and OER activity. In this review, current knowledge regarding state‐of‐the‐art perovskite oxides for acidic water oxidation electrocatalysts is summarized. First, the fundamental OER mechanism of electrocatalysts in acidic media is introduced briefly. Second, Ir‐ and Ru‐based perovskite oxides in acidic solutions are provided, focusing on their stability and OER activity. Finally, some challenges facing the development of perovskite oxide‐based electrocatalysts, and a perspective on their future are discussed.

Abstract Hybridized 1D/2D CuGeO 3 /graphene composites are applied as the oxygen–electrode electrocatalysts for Li–O 2 batteries. The CuGeO 3 /graphene composites are synthesized by the crystallographic alignment of CuGeO 3 nanowires on graphene, rendering strong heteroepitaxial coupling between the 1D oxide nanostructures and the 2D electrically conducting graphene. The inherited excellent electrocatalytic activity of the CuGeO 3 /graphene composites leads to lower overpotentials and more stable cycling performance of Li–O 2 cells than CuGeO 3 nanowires and graphene. The relationships between CuGeO 3 nanowires and graphene are studied for the oxygen reduction and oxygen evolution activity in both aqueous and nonaqueous solutions, and the electrocatalytic activity is improved by manipulating the redox pair and sp3/sp2 via surface chemical modification.

In article number 1802319, by Dong-Wan Kim and co-workers, unique 3D architectures of quaternary (Co1−xNix)(S1−yPy)2/Graphene hybrids are developed as high-performance bifunctional electrocatalysts for overall water splitting. By structural and compositional engineering, doughnut-like shaped 3-dimensional architectures of (Co1−xNix)(S1−yPy)2/Graphene are successfully synthesized. (Co1−xNix)(S1−yPy)2/Graphene achieves excellent electrocatalytic hydrogen and oxygen evolution reaction performance as a bifunctional electrocatalyst for overall water splitting.

Abstract Developing low‐cost, highly active, and stable bifunctional electrocatalysts is a challenging issue in electrochemical water electrolysis. Building on 3D architectured electrocatalysts through structural and compositional engineering is an effective strategy to enhance catalytic activities as well as stability and durability. Herein, 3D architectures of quaternary Co‐Ni‐S‐P compounds coupled with graphene ((Co 1− x Ni x )(S 1− y P y ) 2 /G) electrocatalysts are proposed, in which nanosheets are self‐assembled to form 3D architectures with round and flat doughnut‐like shapes, toward overall water splitting. Benefiting from the 3D architectures and Ni, P substitution, (Co 1− x Ni x )(S 1− y P y ) 2 /G exhibits superior electrocatalytic activities with low overpotentials of 117 and 285 mV at 10 mA cm −2 and Tafel slopes of 85 and 105 mV dec −1 for hydrogen and oxygen evolution reactions, respectively, in alkaline media. In addition, minimal increases in overpotential are observed, even after the 10 000th voltammetric cycle and continuous chronopotentiometric testing over 50–100 h, confirming the high stability and durability of (Co 1− x Ni x )(S 1− y P y ) 2 /G. When used as both cathode and anode, (Co 1− x Ni x )(S 1− y P y ) 2 /G achieves excellent overall water splitting performance with a cell potential as low as 1.65 V, reaching a current density of 10 mA cm −2 with no obvious decay after 50 h, demonstrating that (Co 1− x Ni x )(S 1− y P y ) 2 /G is an efficient bifunctional electrocatalyst for overall water splitting.

Aqueous zinc-ion batteries (AZIBs) are considered suitable devices for large-scale energy storage systems. Vanadium sulfides have gained wide attention as AZIB cathode materials owing to their low cost, high specific capacity, and fast Zn-ion insertion/extraction ability. However, a thorough examination of their actual operation as AZIB cathodes remains lacking. In this study, we synthesized three types of vanadium sulfides/reduced graphene oxide (VxS8/rGO, x = 2, 5, and 6), fabricated electrodes from these materials, and systemically explored their Zn-ion storage mechanisms and kinetics. All three VxS8/rGO electrodes required an electrochemical activation step, which involved charging over 1.8 V (vs. Zn/Zn2+), to obtain high reversible discharging–charging capacity. The V5S8/rGO and V6S8/rGO electrodes exhibited structural and morphological evolution during electrochemical activation and maintained 70% of their capacities for 700 cycles at a current density of 5 A g−1. The V2S8/rGO electrode maintained its initial state during repeated discharge–charge cycling and, thus, exhibited exceptional long-term cycling stability with 99% capacity retention for 700 cycles at the same current density. These findings highlight the importance of an in-depth study of vanadium sulfide materials requiring electrochemical activation to achieve high-power- and energy–density AZIBs.

• We focus on the recent development of Mg-based alloys for Li metal batteries. • Various strategies for synthesizing Mg alloy system-based Li anodes are discussed. • Perspectives for designing an advanced Mg-based Li metal anode are presented. Lithium metal has been considered the ultimate anode material in Li rechargeable batteries because of its exceptionally high theoretical specific capacity (3860 mAh g −1 ) and extremely low redox potential (−3.04 V vs. standard hydrogen electrode). However, the uncontrollable formation of dendritic Li during Li plating/stripping cycling processes generates electrochemically disconnected Li chunks from the electrode, which consumes an active Li source in the electrolyte, thus degrading the electrolyte and leading to low Coulombic efficiency and safety concerns in Li rechargeable batteries. Therefore, the development of stable Li-metal anodes (LMAs) is required for highly reversible Li plating/stripping on the anode side. In this regard, magnesium metal and Mg-based alloys have attracted considerable attention as new LMAs because of their good compatibility with Li and high lithiophilicity. In this review, we introduce the recent advances and strategies for Mg-metal- and Mg-based alloy materials to achieve high durability in next-generation Li-ion batteries and all-solid-state batteries. In addition, we discuss the challenges in the development of Mg-based alloys and their future perspectives. The comprehensive understanding of Mg-metal- and Mg-based alloy materials for LMAs in this review will offer the reader the inspiration to establish an effective strategy for future research.

ABSTRACT Proton exchange membrane water electrolysis (PEMWE) requires Pt‐based hydrogen evolution reaction (HER) electrocatalysts, which makes current systems costly. Low‐cost alternatives have struggled to meet the requirements of both electrocatalytic activity and durability at high‐current density operations. Here, we developed phosphorus‐modified nickel with ruthenium nanoclusters self‐supported on carbon paper (P–NiRu/CP) as efficient HER electrocatalysts. By leveraging metal–organic framework precursors and optimizing the phosphidation process, a dynamic interface between Ru, Ni, and P exhibited optimized hydrogen adsorption/desorption energies and facilitated hydrogen mobility, promoting efficient Tafel recombination. The P–NiRu/CP exhibited an overpotential of 22 mV at 10 mA cm −2 and a Tafel slope of 29 mV dec −1 , outperforming benchmark Pt/C. Computational studies revealed that the dynamic interface in P–NiRu/CP enhanced the electrocatalytic activity. When employed as the cathode in a PEMWE single cell (with commercial IrO 2 as the anode) operating with pure deionized water, P–NiRu/CP achieved 2.05 V at 3.0 A cm −2 with stable operation over 500 h, highlighting P–NiRu/CP as a cost‐effective, durable, and scalable electrocatalyst for sustainable hydrogen production.