as a particularly promising and appealing technology because it has the potential to be both environmentally friendly and low cost. [2] This application creates demand for non-noble-metal-based electrocatalysts to substitute for the currently used highcost Pt catalysts; however, the development remains extremely challenging.High-entropy materials (HEMs) with unique microstructures and unprecedented physicochemical and mechanical properties have attracted a great deal of research interest in many different applied research fields. [3,4] High-entropy alloys (HEAs), as a prominent and already wellestablished group of HEMs, are generally defined as containing five or more principal components alloyed into a crystalline solid-solution phase with unexpected stability and chemical complexity. Many HEAs have demonstrated superior properties relative to traditional alloys, including unprecedented fracture toughness at cryogenic temperatures, [5] ultra-high mechanical performance overcoming the trade-off between strength and ductility, [6] and excellent catalytic selectivity and activities. [7] Largely because of their proximal arrangement of Electrochemical water splitting offers an attractive approach for hydrogen production. However, the lack of high-performance cost-effective electrocatalyst severely hinders its applications. Here, a multinary highentropy intermetallic (HEI) that possesses an unusual periodically ordered structure containing multiple non-noble elements is reported, which can serve as a highly efficient electrocatalyst for hydrogen evolution. This HEI exhibits excellent activities in alkalinity with an overpotential of 88.2 mV at a current density of 10 mA cm −2 and a Tafel slope of 40.1 mV dec −1 , which are comparable to those of noble catalysts. Theoretical calculations reveal that the chemical complexity and surprising atomic configurations provide a strong synergistic function to alter the electronic structure. Furthermore, the unique L1 2 -type ordered structure enables a specific site-isolation effect to further stabilize the H 2 O/H* adsorption/desorption, which dramatically optimizes the energy barrier of hydrogen evolution. Such an HEI strategy uncovers a new paradigm to develop novel electrocatalyst with superior reaction activities.As society seeks to drastically reduce the future usage of fossil fuels, molecular hydrogen is widely recognized as one of the most sustainable and regenerative alternative energy resources. [1] When considering the wide range of hydrogen production methods, electrochemical water splitting has been identifiedThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.

It is a challenge to prepare organic electrodes for sodium-ion batteries with long cycle life and high capacity. The highly reactive radical intermediates generated during the sodiation/desodiation process could be a critical issue because of undesired side reactions. Here we present durable electrodes with a stabilized α-C radical intermediate. Through the resonance effect as well as steric effects, the excessive reactivity of the unpaired electron is successfully suppressed, thus developing an electrode with stable cycling for over 2,000 cycles with 96.8% capacity retention. In addition, the α-radical demonstrates reversible transformation between three states: C=C; α-C·radical; and α-C− anion. Such transformation provides additional Na+ storage equal to more than 0.83 Na+ insertion per α-C radical for the electrodes. The strategy of intermediate radical stabilization could be enlightening in the design of organic electrodes with enhanced cycling life and energy storage capability.

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A biopolymer-chitosan based Supramolecular Hydrogel type solid state Electrolyte (SHE) is prepared via a simple and fast cross-linking between chitosan and Li/Ag. The obtained SHE itself shows high thermal stability and excellent flexible and mouldable properties. When integrated in an asymmetric supercapacitor with MnO as the positive electrode and active carbon as the negative electrode, it can survive more than 10 000 cycles with the areal capacity of 10 mF cm at the 1.8 mA cm current density.

time-consuming, entailing hazardous chemicals or harsh fabrication conditions, and not universal for large-scale application. [4] For example, Hu and co-workers used phosphomolybdic acid (PMo) to initiate the polymerization of polypyrrole for 12 h, which was then subjected to an annealing process to finally obtain the pomegranatelike N, P-doped Mo 2 C@C nanospheres. [3g] The poisonous nature of the pyrrole monomer reactant and the prolonged polymerization process limits practical applications of this method. Besides, ions exchange resin was used to absorb the molybdenum source for more than 20 h, and the composite was then annealed to give rise to Mo 2 C nanoparticles wrapped in the carbon matrix. [5] The adsorptive process is really time-consuming and the utilization of the molybdenum salts is extremely low. As a result, it remains a great challenge to directly and controllably synthesize highly efficient TMC-based electrodes for lithium-ion batteries.Moreover, in view of large volume change of TMCs during the repeating lithiation/delithiation process, porous structure with sufficient void space had been considered as an effective path to mitigate the strike of volume expansion. Previous reports show that interconnected porous nanosheets, arranging into highly separated and permeable porous networks, have Layered stacking and highly porous N, P co-doped Mo 2 C/C nanosheets are prepared from a stable Mo-enhanced hydrogel. The hydrogel is formed through the ultrafast cross-linking of phosphomolybdic acid and chitosan. During the reduction of the composite hydrogel framework under inert gas protection, highly porous N and P co-doped carbon nanosheets are produced with the in situ formation of ultrafine Mo 2 C nanoparticles highly distributed throughout the nanosheets which are entangled via a hierarchical lamellar infrastructure. This unique architecture of the N, P co-doped Mo 2 C/C nanosheets tremendously promote the electrochemical activity and operate stability with high specific capacity and extremely stable cycling. In particular, this versatile synthetic strategy can also be extended to other polyoxometalate (such as phosphotungstic acid) to provide greater opportunities for the controlled fabrication of novel hierarchical nanostructures for next-generation high performance energy storage applications.

Si-based nanostructure composites have been intensively investigated as anode materials for next-generation lithium-ion batteries because of their ultra-high-energy storage capacity. However, it is still a great challenge to fabricate a perfect structure satisfying all the requirements of good electrical conductivity, robust matrix for buffering large volume expansion, and intact linkage of Si particles upon long-term cycling. Here, we report a novel design of Si-based multicomponent three-dimensional (3D) networks in which the Si core is capped with phytic acid shell layers through a facile high-energy ball-milling method. By mixing the functional Si with graphene oxide and functionalized carbon nanotube, we successfully obtained a homogeneous and conductive rigid silicon-based gel through complexation. Interestingly, this Si-based gel with a fancy 3D cross-linking structure could be writable and printable. In particular, this Si-based gel composite delivers a moderate specific capacity of 2711 mA h g at a current density of 420 mA g and retained a competitive discharge capacity of more than 800.00 mA h g at the current density of 420 mA g after 700 cycles. We provide a new method to fabricate durable Si-based anode material for next-generation high-performance lithium-ion batteries.

Developing noble‐metal‐free based electrocatalysts with high activity, good stability, and low cost is critical for large‐scale hydrogen production via water splitting. In this work, hollow FeP nanoparticles densely encapsulated in carbon nanosheet frameworks (donated as hollow FeP/C nanosheets), in situ converted from Fe‐glycolate precursor nanosheets through carbonization and subsequent phosphorization, are designed and synthesized as an advanced electrocatalyst for the hydrogen evolution reaction. FeP hollow nanoparticles are transformed from intermediate Fe3O4 nanoparticles through the nanoscale Kirkendall effect. The two‐dimensional architecture, densely embedding FeP hollow nanoparticles, provides abundant accessible active sites and short electron and ion pathways. The in situ generated carbon nanosheet frameworks can not only offer a conductive network but also protect the active FeP from oxidation. As a result, hollow FeP/C nanosheets exhibit excellent electrocatalytic performance for the hydrogen evolution reaction in 0.5 m H2SO4 with a quite low overpotential of 51.1 mV at 10 mA cm−2, small Tafel slope of 41.7 mV dec−1, and remarkable long‐term stability. The study highlights the in situ synthesis of two‐dimensional metal phosphide/C nanocomposites with highly porous features for advanced energy storage and conversion.

Here we report a new type of white light-emission material that is free of rare earth metals, fabricated by conveniently compositing carbon dots (CDs) with Zr(iv)-based metal–organic frameworks (MOFs).