Ni3Se2 3D hierarchical mesoporous architectures comprising 2D nanosheets are synthesized through an ionothermal process, delivering exceptional electrochemical performance in supercapacitors.

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Chlorine (Cl)‐based batteries such as Li/Cl2 batteries are recognized as promising candidates for energy storage with low cost and high performance. However, the current use of Li metal anodes in Cl‐based batteries has raised serious concerns regarding safety, cost, and production complexity. More importantly, the well‐documented parasitic reactions between Li metal and Cl‐based electrolytes require a large excess of Li metal, which inevitably sacrifices the electrochemical performance of the full cell. Therefore, it is crucial but challenging to establish new anode chemistry, particularly with electrochemical reversibility, for Cl‐based batteries. Here we show, for the first time, reversible Si redox in Cl‐based batteries through efficient electrolyte dilution and anode/electrolyte interface passivation using 1,2‐dichloroethane and cyclized polyacrylonitrile as key mediators. Our Si anode chemistry enables significantly increased cycling stability and shelf lives compared with conventional Li metal anodes. It also avoids the use of a large excess of anode materials, thus enabling the first rechargeable Cl2 full battery with remarkable energy and power densities of 809 Wh kg−1 and 4,277 W kg−1, respectively. The Si anode chemistry affords fast kinetics with remarkable rate capability and low‐temperature electrochemical performance, indicating its great potential in practical applications.

Metallic group VIB transition metal dichalcogenides (1T-TMDs) have attracted great interest because of their outstanding performance in electrocatalysis, supercapacitors, batteries, and so on, whereas the strict fabrication conditions and thermodynamical metastability of 1T-TMDs greatly restrict their extensive applications. Therefore, it is significant to obtain stable and high-concentration 1T-TMDs in a simple and large-scale strategy. Herein, we report a facile and large-scale synthesis of high-concentration 1T-TMDs via an ionic liquid (IL) assisted hydrothermal strategy, including 1T-MoS2 (the obtained MoS2 sample was denoted as MoS2-IL), 1T-WS2, 1T-MoSe2, and 1T-WSe2. More importantly, we found that IL can adsorb on the surface of 1T-MoS2, where the steric hindrance, π–π stacking, and hydrogen bonds of ionic liquid collectively induce the formation of the 1T-MoS2. In addition, DFT calculation reveals that electrons are transferred from [BMIM]­SCN (1-butyl-3-methylimidazolium thiocyanate) to 1T-MoS2 layers by hydrogen bonds, which enhances the stability of 1T-MoS2, so the MoS2-IL performs with high stability for 180 days at room temperature without obvious change. Furthermore, the MoS2-IL exhibits excellent HER performance with an overpotential of 196 mV at 10 mA cm–2 in acid conditions.

Molybdenum sulfide (MoS2) has extensively attracted attention as a promising nonprecious metal catalyst for the electrochemical hydrogen evolution reaction (HER). Nevertheless, synergistically enhancing the intrinsic conductivity and active sites of MoS2 is the pivotal challenge to build up its hydrogen production performance. Herein, a facile ionic liquid-assisted hydrothermal and subsequent annealing treatment strategy is first reported to synthesize W-doped MoS2 nanosheets supported on carbon cloth (Mo1‑x W x S y /CC). The experimental results prove that the substitutional W doping can effectively activate the catalytic activity of the inert basal plane of MoS2 due to the generation of sulfur vacancies. Density functional theory calculations further confirm that W doping and S vacancies reduce the band gap of MoS2 and promote the adsorption of H atoms, thereby greatly improving the HER performance. The synergistic effects of W doping and S vacancies endow this material remarkable HER performance with a low Tafel slope of 49.3 mV dec–1 and an overpotenial of 165 mV for 10 mA cm–2 in 0.5 M H2SO4 solution. In short, our new strategy provides a simple and efficient pathway to synthesize Mo1‑x W x S y /CC, and it can be applied to the design of other materials possessing multifarious merits.

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Copper-based materials have been extensively developed as electrocatalysts for water oxidation due to their promising efficiency and large abundance. Among them, copper telluride could be a potential electrocatalyst but is rarely reported compared with other copper chalcogenides. In this work, rationally designed copper telluride nanosheet arrays on copper foil are fabricated via a facile ionic liquid (1-butyl-3-methylimidazole chloride, [Bmim]­Cl) assisted hydrothermal process. The ionic liquid serves as the solvent and etching agent, promoting the progress of reaction and affecting the morphology of products and the corresponding oxygen evolution reaction (OER) performance. The resulting layer-structure electrocatalysts provide a larger specific surface area and more exposed surface atoms as well as a tight interface with good adhesion to the substrate, thereby accelerating charge transfer and mass diffusion. Based on the above-mentioned advantages, the copper telluride electrode exhibits favorable catalytic OER activity and long-term stability in alkaline media. This work not only expands the variety of OER electrocatalysts but also provides a practicable approach to developing active and stable non-noble materials toward electrochemical water-splitting systems.