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Vanadium dioxide, as one of superior pseudocapacitive electrode candidates in supercapacitors, suffers from the detrimental dissolution in aqueous electrolytes and poor intrinsic electronic conductivity. Herein, an ultrathin Ni3N shell is deposited on the VO2 surfaces (VO2@Ni3N) to inhibit the inevitable dissolution during charge/discharge processes. Meanwhile, the Ni3N coating layer also provides sufficient electron transport pathways for the rapid surface faradic reactions of VO2, promoting the electrochemical reaction kinetics. The designed VO2@Ni3N anode exhibits significant energy storage ability, especially at large current density (2058 F g−1 at 1 A g−1, 711 F g−1 at 7 A g−1), and the considerable cycling lifespans (capacitance retention of 91.3% after 5000 cycles). The asymmetric supercapacitor presents an energy density of 41.73 Wh kg−1 at a power density of 1176.7 W kg−1. This study may enlighten the design of advanced pseudocapacitive materials for practical electrochemical energy storage technologies. [ABSTRACT FROM AUTHOR]

Regulating lithium deposition and stripping behavior during cycles is critical for constructing high-performance and stable lithium metal anodes (LMAs). Herein, a three-dimensional (3D) flexible hierarchical carbon clothes/carbon nanotube (CC/CNTs) host decorated with uniform lithiophilic Ag nanoseeds is obtained via a facile ultrafast Joule heating (UJH) method. Benefiting from high conductivity and large space for Li storage, the as-prepared CC/CNTs@Ag-Li anode displays favorable cycling efficiency and long-life stability. Moreover, the planted Ag lithiophilic sites can efficiently alleviate the growth of lithium dendrites. The synergistic effect of 3D conductive CC/CNTs and Ag nanoseeds endows the skeleton to guide the uniform deposition of Li during the plating/stripping process. The full cells assembled with LiFePO4 (LFP) cathode and CC/CNTs@Ag-Li anode present a high discharge capacity of 155.9 mA h g−1 at 0.1 C and a good capacity retention of 91.4% after 80 cycles at 1 C. The novel design strategy sheds new light on the synthesis of novel alkali metal anodes for energy storage. [ABSTRACT FROM AUTHOR]

This article, titled "3D Host Design Strategies Guiding 'Bottom-Up' Lithium Deposition: A Review," discusses the advancements, challenges, and future prospects of achieving bottom-up lithium deposition. The authors, Zhen Chen, Minghua Chen, Stefano Passerini, and their colleagues, explore the construction strategies and 3D hosts that can attract and capture lithium ions to promote uniform and dendrite-free lithium deposition. The article draws an analogy to the Monkey King from the Chinese novel "Journey to the West," highlighting the gourd in his hand as a representation of the function of attracting Li+ ions. [Extracted from the article]

Rational synthesis of advanced anode materials is vital in developing high-performance sodium ion batteries. In this work, we report a facile hydrothermal strategy for construction of carbon fibre cloth (CFC) supported MoS2 nanosheet arrays. Interconnected NoS2 nanosheets of 5–10 nm are uniformly grown on the surface of CFC forming arrays structure. Good adhesion and high porosity are obtained in the CFC/MoS2 arrays. When evaluated as anodes of sodium ion batteries, the CFC/NoS2 arrays deliver a high specific capacity of 413 mAh g−1 at a current density of 0·5 A g−1, and 176 mAh g−1 at a current density of 3 A g−1. Additionally, good rate performance and cycling life are proven for the CFC/MoS2 arrays. The good performance is ascribed to the CFC network and arrays architecture. Our synthetic method can be used for fabrication of other advanced metal sulfides anodes for sodium ion batteries. Carbon fibre cloth (CFC) supported MoS2 arrays electrodes are synthesized via a hydrothermal method and exhibit a noticeable electrochemical performance as anode of sodium ion batteries. [ABSTRACT FROM AUTHOR]

In response to the change of energy landscape, sodium‐ion batteries (SIBs) are becoming one of the most promising power sources for the post‐lithium‐ion battery (LIB) era due to the cheap and abundant nature of sodium, and similar electrochemical properties to LIBs. The electrochemical performance of electrode materials for SIBs is closely bound up with their crystal structures and intrinsic electronic/ionic states. Apart from nanoscale design and conductive composite strategies, heteroatom doping is another effective way to enhance the intrinsic transfer characteristics of sodium ions and electrons in crystal structures to accelerate reaction kinetics and thereby achieve high performance. In this review, the recent advancements in heteroatom doping for sodium ion storage of electrode materials are reviewed. Specifically, different doping strategies including nonmetal element doping (e.g., nitrogen, sulfur, phosphorous, boron, fluorine), metal element doping (magnesium, titanium, iron, aluminum, nickel, copper, etc.), and dual/triple doping (such as N–S, N–P, N–S–P) are reviewed and summarized in detail. Furthermore, various doping methods are introduced and their advantages and disadvantages are discussed. The doping effect on crystal structure and intrinsic electronic/ionic state are illustrated and the relationship with capacity and energy/power density is interrogated. Finally, future development trends in doping strategies for advanced SIBs electrodes are analyzed. [ABSTRACT FROM AUTHOR]

Nanostructured tin-based anodes are promising for both lithium and sodium ion batteries (LIBs and SIBs), but their performances are limited by the rate capability and long-term cycling stability. Here, ultrathin SnO nanoflakes arrays are in situ grown on highly conductive graphene foam/carbon nanotubes substrate, forming a unique, flexible, and binder-free 3D hybrid structure electrode. This electrode exhibits an excellent Na+ storage capacity of 580 mAh g−1 at 0.1 A g−1, and to the best of our knowledge, has the longest-reported high-rate cycling (1000 cycles at 1 A g−1) among tin-based SIB anodes. Compared with its LIB performance, the enhanced pseudocapacitive contribution in SIB is proved to be the origin of fast kinetics and long durability of the electrode. Moreover, Raman peaks from the full sodiation product Na15Sn4 at 75 and 105 cm−1 are successfully detected and also proved by density functional theory calculations, which could be a promising clue for structure evolution analysis of other tin-based electrodes. [ABSTRACT FROM AUTHOR]

Transition metal oxides anodes of lithium ion batteries (LIBs) usually suffer from low reaction kinetics with slow charge/ions transfer resulting from severe volume variation. In this work, thin porous copper shell is homogeneously coated on the CoO nanowires forming CoO/Cu hetero-structured arrays. Cu shell not only acts as a conductive network, but also serves as a protective “armor” layer to keep electrode stable upon cycling. Meanwhile, 3D porous architecture with large surface area is well preserved in the CoO/Cu hetero-structured arrays. Due to enhanced electron/ion transfer characteristics and strengthened electrode structure, the as-prepared CoO/Cu hetero-structured arrays exhibit much higher electrochemical reactivity with lower polarization and better reversibility due to the introduction of thin Cu shell. Additionally, enhanced discharge capacity and large-rate performances are also demonstrated in the CoO/Cu hetero-structure arrays when compared with the pure CoO nanowires counterpart. [ABSTRACT FROM AUTHOR]

Customized hierarchical porous metal oxide arrays is of great importance for construction of high-performance electrochemical devices. In this work, we report hierarchical porous (HP)-NiO sheets arrays by a facile hydrothermal method. Interestingly, the obtained NiO sheets arrays show HP systems, and are composed of cat-ear-like sheets main structure and interconnected nanosheets secondary structure. Moreover, the secondary nanosheets are highly porous and consist of cross-linked nanoparticles of 30–100 nm. The electrochemical performances of the HP-NiO sheets arrays are evaluated as anode for Li ion batteries. Compared with the normal NiO sheets arrays, enhanced electrochemical performances are achieved for the HP-NiO sheets, including higher capacity, better cycling life and high-rate capability. The HP-NiO sheets can deliver a specific capacity of 511 mAh g −1 at 3 A g −1 , higher than the normal NiO sheets arrays (374 mAh g −1 at 3 A g −1 ), due to the hierarchical porous array configuration with large surface area, fast ion diffusion path and better accommodation of volume change. [ABSTRACT FROM AUTHOR]

High performance of lithium ion batteries (LIBs) relies largely on scrupulous design of bespoke active materials. Herein, we report a facile controllable electrospinning method for preparation of Co 3 O 4 nanotubes with diameters of 200–300 nm. The obtained Co 3 O 4 nanotubes are composed of interconnected nanoparticles of 20–40 nm and show polycrystalline feature. As anode materials for LIBs, the resultant Co 3 O 4 nanotubes show higher specific capacity and better cycle stability (856.4 mAh g −1 at 0.25 C and 677.2 mAh g −1 at 1 C up to 60 cycles), as well as enhanced rate capability as compared to Co 3 O 4 nanowire counterparts (805.1 mAh g −1 at 0.25 C and 587.9 mAh g −1 at 1 C). The performance enhancement mainly comes from the multiple advantages of nanotube configuration, such as higher surface areas, faster transportation path for ion/electron. It is expected that the as-prepared Co 3 O 4 nanotubes are also promising active material for supercapacitors, chemical sensors and electrocatalysis. [ABSTRACT FROM AUTHOR]

This paper describes investigations on the coupling discharge process between laser keyhole plasma and arc plasma during laser-arc welding. The characteristics of single arc plasma and hybrid arc plasma in different locations were comparably estimated by spectral diagnosing. Together with the plasma behavior observation, the particle exchanges between laser keyhole plasma and arc plasma were analyzed. During laser-arc welding, the keyhole plasma acts as an excellent connector between arc plasma and workpiece, resulting in a concentration of electron flows. Coupling discharge leads to the difference in the local thermodynamic equilibrium (LTE) state along the column of the hybrid arc plasma. The keyhole part of the hybrid arc plasma possesses the smallest deviation from absolute LTE state, which benefits the transfer from electric energy to heat during welding. [ABSTRACT FROM PUBLISHER]

MoSe 2 with substantial redox sites and large interlayer space (0.64 nm) has been regarded as an attractive alternative for sodium-ion storage. However, the reversible capacity of the MoSe 2 electrode quickly decays due to the degeneration of the layered structure. Herein, dual-layer coated MoSe 2 nanosheets (MoSe 2 @C@MoO x) produced by the hydrothermal reaction and atomic layer deposition are proposed to enhance the entire structural durability. In this design, the middle coating layer of carbon with physically elastic and electronically conductive features can buffer volume expansion in the reaction process, enhance the electronic conductivity of MoSe 2 and MoO x , and boost the reaction kinetics. The outer coating layer of MoO x as a solid-state electrolyte can enhance cyclic stability. Meanwhile, MoO x participates in the Na + storage process, which enhances the reversible capacity of the entire electrode. The MoSe 2 @C@MoO x electrode demonstrates highly initial discharge capacity (645 mA h g−1) and outstanding cyclic stability (520 mA h g−1 after 200 cycles) compared with uncoated or carbon-coated MoSe 2 electrode. Additionally, the Na+ storage mechanism confirmed by ex-situ X-ray diffraction suggested that the Se element is formed after charging instead of the MoSe 2 component. This design may provide a new paradigm of other nanomaterials for energy storage. MoSe 2 has been applied to metal-ion batteries, but it usually exhibited poor cyclic stability due to low electrical conductivity and large volume variations. Herein, MoSe 2 @C@MoO x nanosheets are first obtained through hydrothermal followed by atomic layer deposition (ALD). The enhanced electrochemistry performance of MoSe 2 @C@MoO x owes to the synergetic contribution from the elastic and conductive carbon interlayer structure and the MoO x with the suitable thickness (50 cycles, 50-ALD). [Display omitted] • The elastic and conductive carbon as interlayer can buffer volume variation. • The carbon interlayer can improve conductivity and enhance utilization of MoSe 2 and MoO x. • MoO x ensures the structural integrity and it can participate in the reaction to increase capacity. • MoSe 2 @C@MoO x nanosheets exhibit enhanced rate capability and cycling stability. [ABSTRACT FROM AUTHOR]