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Single-walled carbon nanohorns (SWCNHs), which are sealed on one side with a conical cap and can self-aggregate, are aggregates with spherical morphology ranging from 30 to 100 nm and include dahlia, bud, and seed structures. These SWCNHs are suitable for electromagnetic wave absorption (EMWA) due to their conductivity loss. However, conductivity loss, which is part of three primary loss mechanisms, leads to SWCNHs suffering from impedance mismatching and a narrow effective absorption bandwidth (EAB). In this work, the content of vacancy-type defects in "dahlia-like" nitrogen-doped single-walled carbon nanohorns (NSWCNHs) is regulated by dielectric barrier discharge (DBD) plasma with argon to adjust their polarization and impedance matching. The high-energy argon ions from the plasma impact the bonds between the carbon atoms and adsorbed oxygen, leading to the sputtering of oxygen atoms from the surface and resulting in an increase in surface disorder and defect content. Vacancy-type defects improved polarization loss and optimized impedance matching, leading to the satisfactory EMWA performance of NSWCNHs. The NSWCNHs exhibit an outstanding minimum reflection loss (RLmin) of −57.94 dB when subjected to argon DBD treatment for 5 minutes, achieving this remarkable result at a thickness of 1.9 mm. Additionally, the effective absorption bandwidth (EAB) can cover 4.78 GHz after a treatment period of 1 minute. These results suggest that NSWCNHs have great potential as high-efficiency EMWA materials and demonstrate a new approach for designing high-performance EMWA absorbers. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (AZIBs) have been considered next-generation promising high-energy storage systems due to their cost-effectiveness and high safety. Nevertheless, the instability of the Zn metal anode posed by dendrite growth and volume changes presents a significant hurdle for AZIB commercialization. Here, we introduce a novel approach using a ZnIn2S4 nanoflower-coated carbon cloth (ZISG-CC) with hierarchical spatial channels to guide the nucleation and deposition of Zn, thereby constructing a stable Zn metal anode. The designed ZISG-CC electrode exhibits distinctive features, including an enlarged surface area, enhanced zincophilicity, and in situ formation of a ZnS/In interphase during the initial discharge process. These characteristics facilitate uniform Zn nucleation and the formation of a stable electrolyte–anode interface, enabling excellent reversibility of the Zn anode. As a result, the Zn/ZISG-CC anode demonstrates outstanding charge–discharge cycling performance in a symmetric cell, achieving 550 cycles at 10 mA cm−2/5 mA h cm−2 and 500 cycles at 20 mA cm−2/10 mA h cm−2. Furthermore, the Zn/ZISG-CC‖MnO2-graphene full cell exhibits a high capacity retention of 87.5% after 1000 cycles at 1 A g−1, along with favorable flexibility. This study introduces a novel strategy that utilizes the interaction between the electrode and electrolyte to stabilize the electrolyte–anode interface, enabling advanced Zn anodes in high-performance AZIBs. [ABSTRACT FROM AUTHOR]

Despite the promising potential of zinc-ion batteries (ZIBs) for large-scale energy storage applications, their electrochemical performance is still hindered by zinc dendrites and side reactions. To address these challenges, the optimization of electrolyte composition emerges as a practical and straightforward approach to enhance the coulombic efficiency (CE) and Zn plating/stripping reversibility of ZIBs. Here, mannitol stands out due to its abundance of polar groups and cost-effectiveness, and an electrolyte mixture consisting of 0.02 M mannitol and 2 M ZnSO4 is demonstrated, resulting in an impressive improvement in Zn reversibility compared to the pure ZnSO4 electrolyte. Density functional theory (DFT) calculations and spectroscopic analysis shed light on mannitol's capability to reconstruct the solvation structure of Zn2+ and replace free water molecules. The inhibited dendrite growth on the zinc metal anode is further confirmed through in situ characterization. This work paves the way for the development of long-lifespan ZIBs. [ABSTRACT FROM AUTHOR]

To overcome the limitations of both LDHs and MXenes, we develop a self-sacrifice template strategy using a zeolite imidazolate framework-67 (ZIF-67) to derive Co-LDH anchored on an MXene conductive substrate (Co-LDH/MXene). In this process, ZIF-67 grows on the MXene nanosheets, then spontaneously transforms into Co-LDH/MXene in aqueous solution at room temperature. As the LIB anode, it shows a reversible capacity of 854.9 and 398.0 mAh g−1 at 0.1 and 1 A g−1, respectively. This work proposes a feasible synthesis method for the in situ construction of a Co-LDH/MXene hybrid, which may be suitable for other MXenes. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (ZIBs) with exceptional safety and cost-effective features have captured researchers' attention, but the cathode materials available still need to be further explored. Herein, a flower-like W/WO3 hybrid is developed as a cathode of ZIBs. Impressively, the W/WO3-ZIBs exhibit extraordinary rate performance (158 mA h g−1 under 0.1 A g−1) and remarkable cycling performance (96% over 1000 cycles). Additionally, an electrochemical mechanism based on reversible Zn2+ insertion/extraction in W/WO3 is firstly demonstrated, and the impressive flexibility and excellent capabilities of the soft-packaged batteries are also realized. Therefore, this research will pave a novel consideration of metal/metal oxide hybrids in designing cathodes of ZIBs with high electrochemical performance. [ABSTRACT FROM AUTHOR]

To solve the poor cycling stability of zinc ion batteries (ZIBs) caused by the growth of zinc (Zn) dendrites, a novel method of separator modification is proposed. Herein, graphene oxide (GO), which has many outstanding properties, is applied as a modified material to a glass fiber (GF) separator using a simple vacuum filtration method. A stable and dendrite-free Zn anode can be obtained after 500 cycles in a Zn//Zn symmetrical battery when using a modified separator (GF/GO1), which is mainly owing to the preferential growth of the non-protruding crystal planes of the zinc metal and the uniform nucleation of zinc ions under the action of GO. As proof of concept, full Zn//MnO2 batteries with a GF/GO1 separator exhibited a high specific capacity of 126 mA h g−1 at 0.1 A g−1, a high energy density of 327.5 W h kg−1 (power density of 0.517 W kg−1), and a high power density of 20.8 kW kg−1 (energy density of 253.8 W h kg−1), demonstrating significant improvements compared with the unmodified GF separator. Meanwhile, ZIBs with a GF/GO1 separator exhibited excellent long-term stability with less than 25% capacity fade over 500 cycles at a current density of 0.5 A g−1. ZIBs with a GF separator retain only 37% of their initial capacity after 100 cycles. Furthermore, the GF/GO1 separator can also help to improve the cycle performance and rate performance of lithium metal batteries and to achieve a dendrite-free lithium anode. Full batteries of Li//GF/GO1//LiCoO2 show improved rate and cycling capabilities. A higher energy density of 537.1 W h kg−1 at 0.04 kW kg−1 and higher power density of 1.4 kW kg−1 at 264.6 W h kg−1 can be achieved with a GF/GO1 separator, which is better than many Li metal batteries. This modification of the separator provides an effective approach to designing next-generation batteries exhibiting excellent rate and cycling capabilities, and high energy and power densities. [ABSTRACT FROM AUTHOR]

The development of high-activity and earth-abundant non-noble metal electrocatalysts for the oxygen evolution reaction (OER) is highly desirable but is an ongoing challenge facing us now. In this work, a series of Ni-based layered double hydroxide (LDH) electrocatalyst models are constructed, and their OER performance is systematically screened via density functional theory (DFT) calculations. We discover that the exposed O sites on the pristine NiOOH substrate are more catalytically active than the Ni sites and play a vital role in the OER process. Moreover, introducing a second transition-metal heteroatom dopant is an effective strategy to boost the OER catalytic activity of the NiOOH matrix. Specifically, Ni@NiFe-2 exhibits an extraordinary OER performance with an overpotential of 0.21 V and can compete with or even outperform the current best catalysts such as RuO2 and IrO2. Our theoretical findings pave a new way for exploring high-efficiency OER catalysts and also shed light on NiFe-based LDHs as advanced candidates. [ABSTRACT FROM AUTHOR]

Using the first-principles calypso algorithm for crystal structure prediction, we have predicted two orthorhombic Cmcm and Amm2 structures of ZrB4, which are energetically much superior to the previously proposed WB4-, CrB4-, and MoB4-type structures and stable against decompression into a mixture of Zr and B at ambient pressure. The two orthorhombic structures consist of a hexagonal B ring and ZrB12 units connected by edges and one hexagonal B ring in Cmcm and Amm2 structure, respectively. The calculated large shear modulus (e.g., 229 GPa) and high hardness (42.8 GPa for Cmcm and 42.6 GPa for Amm2) reveal that they are potentially superhard materials. The high hardness is attributed to a stacking of B–Zr–B “sandwiches” layers linked by strong covalent B–B bonding. [ABSTRACT FROM AUTHOR]

Single-walled carbon nanohorns (SWCNHs), which are sealed on one side with a conical cap and can self-aggregate, are aggregates with spherical morphology ranging from 30 to 100 nm and include dahlia, bud, and seed structures. These SWCNHs are suitable for electromagnetic wave absorption (EMWA) due to their conductivity loss. However, conductivity loss, which is part of three primary loss mechanisms, leads to SWCNHs suffering from impedance mismatching and a narrow effective absorption bandwidth (EAB). In this work, the content of vacancy-type defects in "dahlia-like" nitrogen-doped single-walled carbon nanohorns (NSWCNHs) is regulated by dielectric barrier discharge (DBD) plasma with argon to adjust their polarization and impedance matching. The high-energy argon ions from the plasma impact the bonds between the carbon atoms and adsorbed oxygen, leading to the sputtering of oxygen atoms from the surface and resulting in an increase in surface disorder and defect content. Vacancy-type defects improved polarization loss and optimized impedance matching, leading to the satisfactory EMWA performance of NSWCNHs. The NSWCNHs exhibit an outstanding minimum reflection loss (RL min ) of -57.94 dB when subjected to argon DBD treatment for 5 minutes, achieving this remarkable result at a thickness of 1.9 mm. Additionally, the effective absorption bandwidth (EAB) can cover 4.78 GHz after a treatment period of 1 minute. These results suggest that NSWCNHs have great potential as high-efficiency EMWA materials and demonstrate a new approach for designing high-performance EMWA absorbers.

Aqueous zinc-ion batteries (ZIBs) with exceptional safety and cost-effective features have captured researchers' attention, but the cathode materials available still need to be further explored. Herein, a flower-like W/WO 3 hybrid is developed as a cathode of ZIBs. Impressively, the W/WO 3 -ZIBs exhibit extraordinary rate performance (158 mA h g -1 under 0.1 A g -1 ) and remarkable cycling performance (96% over 1000 cycles). Additionally, an electrochemical mechanism based on reversible Zn 2+ insertion/extraction in W/WO 3 is firstly demonstrated, and the impressive flexibility and excellent capabilities of the soft-packaged batteries are also realized. Therefore, this research will pave a novel consideration of metal/metal oxide hybrids in designing cathodes of ZIBs with high electrochemical performance.

Rational design and synthesis of a new silicon carbide/titanium carbide@silicon oxide/titanium dioxide (SiC/TiC@SiO x /TiO 2 ) porous core-shell nanostructured material could significantly enhance the specific capacity, rate capability, and cycle stability of electrodes. The results demonstrate that the specific capacities are 387, 300, 252, 210, 174 and 151 mA h g -1 at 100, 200, 500, 1000, 1500 and 2000 mA g -1 , respectively. The newly designed electrode still exhibits a larger specific capacity of 217 mA h g -1 at 1000 mA g -1 after the 1000th cycle.

Using the first-principles calypso algorithm for crystal structure prediction, we have predicted two orthorhombic Cmcm and Amm2 structures of ZrB4, which are energetically much superior to the previously proposed WB4-, CrB4-, and MoB4-type structures and stable against decompression into a mixture of Zr and B at ambient pressure. The two orthorhombic structures consist of a hexagonal B ring and ZrB12 units connected by edges and one hexagonal B ring in Cmcm and Amm2 structure, respectively. The calculated large shear modulus (e.g., 229 GPa) and high hardness (42.8 GPa for Cmcm and 42.6 GPa for Amm2) reveal that they are potentially superhard materials. The high hardness is attributed to a stacking of B-Zr-B "sandwiches" layers linked by strong covalent B-B bonding.