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Aqueous zinc-ion batteries (ZIBs) have attracted increasing attention due to their low cost and high safety. MoS2 is a promising cathode material for aqueous ZIBs due to its favorable Zn2+ accommodation ability. However, the structural strain and large volume changes during intercalation/deintercalation lead to exfoliation of active materials from substrate and cause irreversible capacity fading. In this work, a highly stable cathode was developed by designing a hierarchical carbon nanosheet-confined defective MoSx material (CNS@MoSx). This cathode material exhibits an excellent cycling stability with high capacity retention of 88.3% and ∼ 100% Coulombic efficiency after 400 cycles at 1.2 A·g−1, much superior compared to bare MoS2. Density functional theory (DFT) calculations combined with experiments illustrate that the promising electrochemical properties of CNS@MoSx are due to the unique porous conductive structure of CNS with abundant active sites to anchor MoSx via strong chemical bonding, enabling MoSx to be firmly confined on the substrate. Moreover, this unique hierarchical complex structure ensures the fast migration of Zn2+ within MoSx interlayer. [ABSTRACT FROM AUTHOR]

A hierarchical nanostructure composed of NiMn-layered double hydroxide (NiMn-LDH) microcrystals grafted on carbon nanotube (CNT) backbone is constructed by an in situ growth route, which exhibits superior supercapacitive performance. The resulting composite material (NiMn-LDH/CNT) displays a three-dimensional architecture with tunable Ni/Mn ratio, well-defined core-shell configuration, and enlarged surface area. An electrochemical investigation shows that the Ni3Mn1-LDH/CNT electrode is rather active, which delivers a maximum specific capacitance of 2960 F g-1 (at 1.5 A g-1), excellent rate capability (79.5% retention at 30 A g-1), and cyclic stability. Moreover, an all-solid-state asymmetric supercapacitor (SC) with good flexibility is fabricated by using the NiMn-LDH/CNT film and reduced graphene oxide (RGO)/CNT film as the positive and negative electrode, respectively, exhibiting a wide cell voltage of 1.7 V and largely enhanced energy density up to 88.3 Wh kg-1 (based on the total weight of the device). By virtue of the high-capacity of pseudocapacitive hydroxides and desirable conductivity of carbon-based materials, the monolithic design demonstrated in this work provides a promising approach for the development of flexible energy storage systems. [ABSTRACT FROM AUTHOR]

A well‐designed hierarchical nanostructure composed of NiMn‐layered double hydroxide (NiMn‐LDH) microcrystals grafted on a carbon nanotube (CNT) backbone is constructed by M. Wei and co‐workers using an in situ growth route, which shows superior supercapacitive performance. On page 2938, an all‐solid‐state asymmetric supercapacitor (SC) with good flexibility is fabricated using the NiMn‐LDH/CNT film and reduced graphene oxide (RGO)/CNT film as the positive and negative electrodes, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Aluminum-doped α-Ni(OH)2 microspheres with flowerlike hierarchical structure (H-Al-α-Ni(OH)2) were successfully synthesized via a facile hydrothermal method with the assistance of ionic liquid (1-butyl-3-methyl imidazolium tetrafluoroborate, [BMIM]BF4). The XRD pattern and elemental analysis confirm that aluminum species incorporates into the lattice of α-Ni(OH)2; SEM and TEM images reveal that the as-prepared microspheres are composed of numerous frizzy nanoflakes shell attaching vertically to the core. The resulting H-Al-α-Ni(OH)2 sample exhibits a specific surface area of 91.2m2/g and a mesopore distribution (2–20nm) based on the BET measurements. Furthermore, the hierarchical H-Al-α-Ni(OH)2 modified electrode displays a couple of well-defined reversible redox peaks (ΔE p =67mV and I a/I c =0.91) and a fast direct electron transfer rate constant (k s =3.32s−1), owing to the high dispersion of active species as well as abundant mass transfer channels which facilitate the mass/electron transfer. In addition, the modified electrode presents a significant electrocatalytic performance towards the oxidation of hydrazine with a linear response range (5.0×10−6–1.0×10−4 M), high sensitivity (144μA/μM cm2), low detection limit (0.8μM) as well as good stability. The hierarchical α-Ni(OH)2 with largely enhanced electrochemical behavior demonstrated in this work can be used in electrochemical sensor and electroanalysis. [Copyright &y& Elsevier]