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Comprehensive Summary: Room‐temperature sodium‐sulfur (RT‐Na/S) batteries display attractive potential in large‐scale energy‐storage, but their practical application was still restricted by the serious dissolution of polysulfides. Herein, supported by the constructing of interface engineering, the metal sulfide‐carbon nanocomposite can be prepared with considerable electrochemical properties. Utilizing the double‐helix structure of carrageenan‐metal hydrogels as precursors, in‐situ metal sulfide (MxSy) nanostructure/3D carbon aerogels (3D CAs) can be successfully constructed. Importantly, with the assistance of the vulcanization process, 3D carbon architecture was maintained in the composites and acted as a skeleton to optimize their structural stability. As the cathode of RT‐Na/S batteries, ZnS/S@C and NiS2/S@C delivered an excellent cycling stability and rate performance (179.8 mAh·g−1 at 20 A·g−1 after 10000 cycling for ZnS/S@C, 220.3 mAh·g−1 at 10 A·g−1 after 3000 cycling for NiS2/S@C). The detailed investigation of mechanism revealed that the powerful adsorption for Na2S4 originated from 3D metal sulfide‐carbon structure. The well‐designed architecture of sulfide‐carbon composites servers as an electrocatalyst to alleviate the shuttle effect of polysulfides, resulting in the long‐term electrochemical stability. Given this, the work is expected to provide promising insights for designing advanced cathode materials for RT‐Na/S batteries. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Room‐temperature sodium‐sulfur (RT‐Na/S) batteries display attractive potential in large‐scale energy‐storage, but their practical application was still restricted by the serious dissolution of polysulfides. Herein, supported by the constructing of interface engineering, the metal sulfide‐carbon nanocomposite can be prepared with considerable electrochemical properties. Utilizing the double‐helix structure of carrageenan‐metal hydrogels as precursors, in‐situ metal sulfide (MxSy) nanostructure/3D carbon aerogels (3D CAs) can be successfully constructed. Importantly, with the assistance of the vulcanization process, 3D carbon architecture was maintained in the composites and acted as a skeleton to optimize their structural stability. As the cathode of RT‐Na/S batteries, ZnS/S@C and NiS2/S@C delivered an excellent cycling stability and rate performance (179.8 mAh·g−1 at 20 A·g−1 after 10000 cycling for ZnS/S@C, 220.3 mAh·g−1 at 10 A·g−1 after 3000 cycling for NiS2/S@C). The detailed investigation of mechanism revealed that the powerful adsorption for Na2S4 originated from 3D metal sulfide‐carbon structure. The well‐designed architecture of sulfide‐carbon composites servers as an electrocatalyst to alleviate the shuttle effect of polysulfides, resulting in the long‐term electrochemical stability. Given this, the work is expected to provide promising insights for designing advanced cathode materials for RT‐Na/S batteries. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs), featuring ordered nanopores with numerous accessible redox sites, have drawn much attention as promising electrode materials for rechargeable batteries. Thus far, however, COF‐based battery electrodes have exhibited limited capacity and unsatisfactory cycling stability due to the unwanted side reactions over their large surface area. Herein, a fluorine‐rich covalent organic framework (F‐COF) as an electrode material with improved stability and performance for potassium‐ion batteries is developed. The fluorinated COF not only stabilizes intercalation kinetics of K+ ions but also reinforces its electron affinity and conductivity, improving the reversibility of bond transitions during discharge–charge cycles. As a result, F‐COF affords a high specific capacity (95 mAh g−1 at fast rates up to 5 C) and excellent cycling stability (5000 cycles with ≈99.7% capacity retention), outperforming the pristine COF‐based electrodes devoid of F atoms. Notably, the experimental capacity of F‐COF approaches its theoretical value, confirming that a large proportion of electroactive sites are being actively utilized. Altogether, this work addresses the significant role of F atoms in improving the K+‐ion storage capability of COFs and provides the rational design principles for the continued development of stable and high‐performance organic electrode materials for energy storage devices. [ABSTRACT FROM AUTHOR]

[Display omitted] The rapid development of electric vehicles has promoted researchers to explore the field of high-capacity batteries. Two-dimensional (2D) materials have been proven to have ultra-high storage capacity due to their unique structural advantages. A first-principles approach was applied here to verify the feasibility of the novel AlB 2 monolayer as an anode material with ultra-high storage capacity for Li/Na-ion batteries. The Li capacity of AlB 2 monolayer is up to 3308.6 mAh/g. Meanwhile, the Na capacity up to 1654.3 mAh/g. It is worth noting that the diffusion barrier of the monolayer is extremely low (Li: 0.50 eV; Na 0.26 eV). The results show that AlB 2 monolayer is a kind of anode material for high energy storage, which provides a new choice for the development of long-life battery. [ABSTRACT FROM AUTHOR]

Captured by the low-cost and high theoretical specific capacity, Na-S systems have garnered much attention. However, their intermediate products (dissolved polysulfide) are always out of control. Considering the excellent space confinements and conductivity, they have been regarded as promising candidates. Herein, the hollow spheres with suitable thickness shell (~20 nm) are designed as hosting materials, accompanied by in-depth complexing. Benefitting from the abundant micro-pores (mainly about conical-type and slits-type pores < 1.0 nm), the active S4 molecules are successfully filled in the pores through vacuum tube sealing technology, effectively avoiding the process from solid S8 to liquid Na2S6. As cathode for Na-S systems, their capacity could remain at 920 mAh g−1 at 0.1 C after 100 cycles. Even at 10.0 C, the capacity still remained at about 310 mAh g−1 after 7000 cycles. Supported by the detailed kinetic behaviors, the improvement of ions diffusion behaviors is noted, bringing about the effective thorough redox reactions. Moreover, the enhanced surface-controlling behaviors further induces the evolution of rate properties. Therefore, their stable phase changing is further confirmed through in situ resistances. Thus, the work is anticipated to offer significant design for hosting carbon materials and complexing manners.

[Display omitted] • A stable 2D T -BN structure was found before and after the adsorption of Li + and Na +. • The pure T -BN sheet showed semiconducting nature, with a bandgap of 1.184 eV. • A high specific capacity was found for both LIBs and NIBs, suggesting an excellent ion storage property. • Lower positive values of OCV confirmed the practicability of T -BN as a promising anode material. An allotrope of graphene named T -graphene has been reported as a promising anode material for the development of the storage capacity of alkaline ion batteries (AIBs). Herein, by first-principles calculations, we have explored the anodic properties of the boron nitride analogue of T -graphene named T -BN. We demonstrate that T -BN hosts stable ion adsorption for both Li- and Na-ion with good structural features. We also found that T -BN has a small bandgap of 1.184 eV, which naturally reduces to zero as ions are adsorbed within the nanosheet. As a result, the theoretical storage capacities are as high as 959.95 mAh/g, and 719.97 mAh/g for Li and Na adsorbed T -BN, respectively, which are much higher than commercial graphite anode. We further show that T -BN has good electrical conductivity, whether it is before and after ion adsorption. Lastly, low open circuit values indicate the superiority of this material as an appealing anode for Li- and Na-ion storage batteries. [ABSTRACT FROM AUTHOR]

• PC 6 monolayer exhibits large storage capacity of 1496.23/1301.07/780.63 mA·h·g−1 for Li/Na/K ion. • Small diffusion barriers and relatively low open-circuit voltages are found for the anode of PC 6 monolayer. • The saturation adsorption systems of PC 6 can maintain good stability even at the temperature of 400 K. The development of two-dimensional (2D) materials in anode has been believed as a significant research direction to promote the innovation of alkali metal-ion batteries. Lately, PC 6 monolayer, a neoteric material, has stimulated people's research enthusiasm owing to its outstanding thermodynamic and electrical natures. In this paper, by employing the first-principles calculation method based on density function theory, the feasibility of PC 6 monolayer acting as an anode in alkali metal-ion batteries has been systematically evaluated. The simulation results indicate that, when acting as anode material, the PC 6 monolayer can not only provide effective adsorption interaction for metal ions which is beneficial for inhibiting the formation of clusters, but also can furnish satisfactory storage capacity (1496.23 mA·h·g−1 for Li, 1301.07 mA·h·g−1 for Na, and 780.63 mA·h·g−1 for K). Meanwhile, PC 6 monolayer can supply appropriate average open-circuit voltages (0.48/0.40/0.64 V for Li/Na/K), which are all within the ideal voltage range of anode material. Importantly, the appraised diffusion behaviors further reflect the isotropic property and wonderful migration performance (0.42/0.46/0.29 eV for Li/Na/K) of PC 6 monolayer for metal ions. Remarkedly, the ab initio molecular dynamics simulations results illustrate that these saturated adsorption systems have excellent deformation resistance at a high temperature of 400 K. These exciting performances endow the PC 6 monolayer with promising application prospects as an anode in alkali metal-ion batteries. [ABSTRACT FROM AUTHOR]

Si microwire array anodes have been prepared by an economical, microelectronics compatible method based on macropore etching. In the present report, evidence of the scalability of the process and the areal capacity of the anodes is presented. The anodes exhibit record areal capacities for Si-based anodes. The gravimetric capacity of longer anodes is comparable to the one of shorter anodes at moderate lithiation/delithiation rates. The diffusion limitation of the lithium ions through the electrolyte in depth among the wires is the limiting factor for cycling longer wires at high rates. PACS: 82.47.Aa; 82.45.Vp; 81.16.-c [ABSTRACT FROM AUTHOR]

[Display omitted] • The YS-Fe 2 N@NC is an effective carrier of sulfur and Na-polysulfides (NaPSs). • The S/YS-Fe 2 N@NC shows excellent electrochemical performance under lean conditions. • The reaction mechanism of NSB was studied by using in/ex-situ characterizations. • The mechanism results are strong evidence for the catalytic conversion of NaPSs. Room temperature sodium-sulfur (RT-Na-S) battery represents an advanced energy storage technology because of low cost and large theoretical energy density. However, RT-Na-S battery technology is facing severe challenges such as dissolution of sodium polysulfide, loss of active material on the surface of anode, serious shuttle effect and poor cycle stability. Herein, we synthesis hollow polar iron nitride nanoparticle encased N-doped carbon yolk shell (YS-Fe 2 N@NC) as sulfur carrier. The synergistic effect of YS-Fe 2 N@NC as well as wide void can be effectively trap polysulfides and improve the conductivity of sulfur-based cathode. The reversible reaction mechanism of Na-S battery is studied by in/ex-situ characterizations, catalytic behaviour of YS-Fe 2 N@NC and Density functional theory (DFT) calculations. The as made S/YS-Fe 2 N@NC composite exhibit promising specific capacity of 1123 mAh g−1 at the rate of 1C for the initial cycle, good rate capability (845 mAh g−1 at 2C) and ultra-stable cycling performance with an ultra-low capacity decay of 0.0724% per cycle. The present work highlights the importance of introducing the Fe 2 N to catalyse the conversion reactions of polysulfide within NC shell for boosting the RT-Na-S battery in term of high storage capacity, rate capability and stability. [ABSTRACT FROM AUTHOR]

This paper presents the development of a microwave puffed wood (MPW) with novel and unique structural features in its internal structure that are based on natural wood (NW). The focus of the research was on the comprehensive visualization of the structural characteristics of MPW from the macroscopic to the microscopic scale followed by an exploration of its impregnation capabilities. The results showed that the volume of MPW increased by about 9% compared to NW due to the presence of a large number of cracked cavities. The CT images indicated that there was a significant difference between the macroscopic cracks produced by microwave processing and the natural cracks in the wood. The mercury intrusion test results showed that macro-pores increased while the micro-pores decreased in the MPW compared to in the NW. The MPW showed good fluid permeability and liquid absorption performance. The phenolic resin penetration rate of the MPW was about 20 times that of the NW, and the material absorption was more than 2 times that of the NW. The crack space enabled the MPW to serve as a fluid transportation and a storage warehouse. MPW is a super container based on natural materials. It has broad potential in more fields, such as in wood composite materials. [ABSTRACT FROM AUTHOR]

High storage capacity and recording-access rate are two critical factors that the current optical storage technology pursues. Efforts on shortening the laser wavelength, increasing the numerical aperture of objective, and increasing the optical drive speed have been made to reach this end. However, these methods have run their full course because of many existing difficulties on the physical and manufacturing aspect. People have to explore innovative ways to satisfy the requirement of both mass data and high rate. Multidimensional optical storage and holographic recording are two promising technologies to increase the capacity of memory and recording rate by orders of magnitude. We report on the fast bits recording in bisazobenzene functional polymer film by femtosecond laser holographic recording. The mechanism of the photo-induced anisotropy of the material is reviewed and discussed. The demonstration of multidimensional holographic recording is presented. Some influence factors in the holographic processing are discussed. [ABSTRACT FROM PUBLISHER]

• The feasibility of a new 2-D material (NP monolayer) as battery electrodes is systematically studied. • It has relatively low open-circuit voltages and ion diffusion barriers. • It shows very high capacities for Li/Na (595.8/1787.5 mA h g−1). • NP is a superior anode material with high storage capacity and ultrafast ion diffusion. The performance of electrode materials is known as one of the most crucial determinations for ion batteries. Here, based on first-principles calculations, we report that a new two-dimensional (2-D) material namely NP monolayer, can be served as a potential electrode material for Li-/Na-ion batteries with high storage capacity and fast diffusion rate. Our results show that the maximum theoretical storage capacity of Li on the NP monolayer is 595.8 mA h g−1, and that of Na reaches up to 1787.5 mA h g−1. Especially for Na, this value is higher than the capacity of most known 2-D anode materials. Meanwhile, the Li/Na diffusion barrier (49 meV/184 meV) is quite small, which can enable fast diffusion rate. The open-circuit voltage (1.49–0.52 V for Li and 1.41–0.2 V for Na) of the NP monolayer is also quite low as an anode material. In addition, the NP monolayer possesses good kinetic and thermodynamic stability, as well as metallic conductivity during the adsorption. Consequently, the NP monolayer can be the potential candidate as the electrode material for Li-/Na-ion batteries. [ABSTRACT FROM AUTHOR]

The rationalized atomic/clusters of Fe/Se/Al are dispersed on N-doped amorphous carbon fibers through electrospinning and direct selenization (DS) processes. The developed product of DS-Fe/Se/Al@NC-650 nanofibers are presented as anode material of SIBs, exhibiting the storage capacity of 432 mAh g−1 at 100 mA g−1 and 99% stability through 700 cycles. • Atomic dispersion of Fe/Al/Se element into carbon framework can enhance the performance of SIBs. • Direct selenization promotes the atomic/cluster dispersions into carbon fibers. • The DS-Fe/Se/Al@NC-650 nanofibers are presented as anode material for stable SIBs. The greater availability of sodium with large storage capacity motivates the fabrication of advanced electrodes materials for sodium ion batteries (SIBs) to promote in potential market of smart appliances. Multiple metals atomic dispersion into carbon framework can enhance the adsorption property of sodium for high performance SIBs. In this work, rationalized atomic/clusters of Fe/Se/Al are dispersed on N-doped amorphous carbon fibers through electrospinning and direct selenization (DS) processes. The developed product of DS-Fe/Se/Al@NC-650 nanofibers are employed as anode materials of SIBs, exhibitinga high specific capacity of 432 mAh g−1 at 100 mA g−1 a desirable cycling stability with a capacity retention of 99 % after 700 cycles. Such an excellent storage capacity initiates through synergistic effects of the uniformly distributed Fe/Se/Al and the interconnected nitrogen-doped carbon network. For the apprehension of capacity and stability of DS-Fe/Se/Al@NC-650 nanofibers for SIBs, the theoretical calculations were carried out and provide strong evidences which proves the electron/ion transport in experimental results. [ABSTRACT FROM AUTHOR]