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The inherently intermittent and regional nature of renewable energy generation drives the growth of large-scale electrical energy storage systems. Aqueous Zn-based batteries matched with conversion-type cathodes have attracted increasing attention owing to their cost effectiveness, abundant reserves, intrinsic safety, and relatively long lifetime. Halogens with unique electron configurations possess an abundance of chemical valence states, high redox potential, and relatively high theoretical capacity and have shown great promise as cathode materials. However, many intractable challenges need to be resolved, such as the shuttle effect and slow kinetics. In this review, redox mechanisms and fundamental challenges associated with aqueous zinc–halogen batteries are summarized first. Subsequently, the research issues and progress related to halogen cathode materials are discussed. Finally, we present a forward-looking perspective for promising aqueous zinc–halogen batteries. By furnishing a nuanced understanding of recent advancements and challenges in this field, the review aspires to offer valuable guidance to researchers, ultimately facilitating the practical application of aqueous zinc–halogen batteries. [ABSTRACT FROM AUTHOR]

Strong yet ductile alloys have long been desired for industrial applications to enhance structural reliability. This work produced two (CoCrNi)93.5Al3Ti3C0.5 medium-entropy alloys with exceptional strength–ductility combinations, via short/medium (3 min/30 min) annealing times after hot-rolling. Three types of intergranular precipitates including MC, M23C6 carbides, and L12 phase were detected in both samples. Noticeably, the high-density of intragranular L12 precipitates were only found in the medium-time annealed sample. Upon inspection of the deformed substructure, it was revealed that the plane slip is the dominant deformation mechanism of both alloys. This is related to the lower stacking fault energy, higher lattice friction induced by the C solute, and slip-plane softening caused by intragranular dense L12 precipitates. Additionally, we noted that the stacking fault and twinning act as the mediated mechanisms in deformation of the short-time annealed alloy, while only the former mechanism was apparent in the medium-time annealed alloy. The inhibited twinning tendency can be attributed to the higher energy stacking faults and the increased critical twinning stress caused by intragranular dense L12 precipitates. Our present findings provide not only guidance for optimizing the mechanical properties of high/medium-entropy alloys, but also a fundamental understanding of deformation mechanisms. [ABSTRACT FROM AUTHOR]

Aqueous zinc–iodine (Zn‐I2) battery is one of the most promising candidates for large‐scale energy storage due to its cost‐effectiveness, environmental friendliness, and recyclability. Its practical application is hindered by challenges including polyiodide "shuttle effect" in the cathode and anode corrosion. In this study, a zinc pyrrolidone carboxylate bifunctional additive is introduced to simultaneously tackle the issues of the polyiodide and Zn anode. It is revealed that the pyrrolidone carboxylate anions decrease the polyiodide concentration by preferential coordination between the pyrrolidone carboxylate anions and I2 based on the Lewis acid‐base effect, suppressing the shuttle effect and therefore improving the conversion kinetics for the iodine redox process. Meanwhile, the pyrrolidone carboxylate anions adsorbed on the Zn anode inhibit Zn corrosion and promote non‐dendritic Zn plating, contributing to impressive Coulombic efficiency and long‐term cycling stability. As a result, the Zn‐I2 full battery with the bifunctional zinc pyrrolidone carboxylate additive realizes a high specific capacity of 211 mAh g−1 (≈100% iodine utilization rate), and an ultralong cycling life of >30 000 cycles with 87% capacity retention. These findings highlight the significant potential of zinc pyrrolidone carboxylate as a transformative additive for aqueous Zn‐I2 batteries, marking a critical advancement in the field of energy storage technologies. [ABSTRACT FROM AUTHOR]

The rational modification of electronic structures to create catalytically active sites has been proved to be a promising strategy to efficiently facilitate the urea oxidation reaction (UOR). Herein, a well-defined nanosheet arrays catalyst of Ni(OH)2 doped with dual cations of Co and Mn on Ni foam (NF) (Co/Mn–Ni(OH)2) is synthesized through a simple hydrothermal process. Benefiting from the advantages of unique structures and modified binding strengths, it is found experimentally that the obtained Co/Mn–Ni(OH)2 catalyst only requires a potential of 1.38 V to deliver a current density of 100 mA cm−2 and exhibits a small Tafel slope of 35 mV dec−1, outperforming single-component-incorporated Ni(OH)2. Moreover, the catalyst has shown excellent stability for 25 h at a current density of 50 mA cm−2. Additionally, first-principles calculations demonstrate that the co-incorporation of Co and Mn remarkably lowers the adsorption barrier of CO(NH2)2* on the catalyst surface, and accelerates the dissociation of the CO(NH2)2* intermediate into CO* and NH* intermediates, which synergistically improve the UOR reaction kinetics. This work provides a generic paradigm for designing advanced and effective catalysts toward the UOR. [ABSTRACT FROM AUTHOR]

The precipitation and transformation of carbides in steel are gaining more interest since they are closely related to the properties of steel. Herein, the precipitation and transformation of carbides during tempering of the 7Cr14 martensitic stainless steel subjected to high‐temperature solution treatment (HTST) are investigated. The results indicate that the precipitation of M3C (300–333 °C) and M23C6 (612–645 °C) carbides occurs during tempering of the HTST steel. The effective precipitation activation energies of M3C and M23C6 carbides are 120 ± 7 and 272 ± 13 kJ mol−1, respectively. The precipitation processes of M3C and M23C6 carbides are dominated by C and Cr atomic diffusion, respectively. Moreover, it is found that two transformation processes occur during tempering with increasing temperature, namely, M3C carbides dissolve in the matrix and then M23C6 carbides precipitate along the boundaries of martensitic laths, and the plate‐like M3C carbides decompose into several globular or rod‐like M23C6 carbides that arrange in a chain‐like morphology. [ABSTRACT FROM AUTHOR]