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As concerns about the safety of lithium‐ions batteries (LIBs) increases, aqueous zinc‐ion batteries (ZIBs) with a lower cost, higher safety, and higher co‐efficiency have attracted more and more interest. However, finding suitable cathode materials is still an urgent problem in ZIBs. In recent years, a lot of significant works have been reported, including manganese‐based cathodes, vanadium‐based cathodes, Prussian blue analog‐based materials, and sustainable quinone cathodes. In this review, some typical cathode materials are introduced. The detailed storage mechanisms and methods for improving the reaction kinetics of the zinc ions are summarized. Finally, the issues, challenges, and the research directions are provided. [ABSTRACT FROM AUTHOR]

To improve the cycling stability and rate performance of SnO 2 –based anode materials applied in lithium ions batteries (LIBs), SnO 2 /graphene oxide (SnO 2 /GO) composite was synthesized by hydrothermal method. The SnO 2 /GO composite material exhibits much more excellent lithium ions storage capacity and cycling stability. The reversible capacity is 612.2 mAhg −1 with the coulombic efficiency of 98.8%, after 100 cycles. Especially, at a high discharge-charge current density (1000 mAg −1 ), the SnO 2 /GO composite showed an outstanding structure stability and rate performance (204.2 mAhg −1 ). Such excellent performance could be attributed to the existence of GO. With the assistance of GO, the composite material achieves more stable structure and high electron conductivity. [ABSTRACT FROM AUTHOR]

A hybrid of multi-walled carbon nanotubes (MWCNTs) anchored with SnS nanosheets is synthesized through a simple solvothermal method for the first time. Interestingly, SnS can be controllably deposited onto the MWCNTs backbone in the shape of nanosheets or nanoparticles to form two types of SnS/MWCNTs hybrids, SnS NSs/MWCNTs and SnS NPs/MWCNTs. When evaluated as an anode material for lithium-ion batteries, the hybrids exhibit higher lithium storage capacities and better cycling performance compared to pure SnS. It is found that the SnS NSs/MWCNTs hybrid exhibits a large reversible capacity of 620mAhg−1 at a current of 100mAg−1 as an anode material for lithium-ion batteries, which is better than SnS NPs/MWCNTs. The improved performance may be attributed to the ultrathin nanosheet subunits possess short distance for Li+ ions diffusion and large electrode-electrolyte contact area for high Li+ ions flux across the interface. It is believed that the structural design of electrodes demonstrated in this work will have important implications on the fabrication of high-performance electrode materials for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Keywords: aqueous batteries; cathode materials; manganese; quinone cathodes; storage mechanisms; vanadium; Zn-ion batteries EN aqueous batteries cathode materials manganese quinone cathodes storage mechanisms vanadium Zn-ion batteries 1 1 1 01/18/21 20210113 NES 210113 B Aqueous zinc ion batteries (ZIBs) b are the most promising rechargeable batteries for the grid energy storage and industrial energy storage for its lower cost and higher safety. The cathode materials consist of Mn-based materials, V-based materials, Prussian blue analogous (PBAs), Quinone and the others materials. Aqueous batteries, cathode materials, manganese, quinone cathodes, storage mechanisms, vanadium, Zn-ion batteries. [Extracted from the article]

Sn chalcogenides, including SnS, Sn2S3, and SnS2, have been extensively studied as anode materials for lithium batteries. In order to obtain one kind of high capacity, long cycle life lithium batteries anode materials, three-dimensional (3D) flower-like hierarchitectures constructed by SnS/SnS2 heterostructure nanosheets with thickness of ~20 nm have been synthesized via a simple one-pot solvothermal method. The obtained samples exhibit excellent electrochemical performance as anode for Li-ion batteries (LIBs), which deliver a first discharge capacity of 1277 mAhg−1 and remain a reversible capacity up to 500 mAhg−1 after 50 cycles at a current of 100 mAg−1. [ABSTRACT FROM AUTHOR]

Secondary batteries have been widespread in the daily life causing an ever-growing demand for long-cycle lifespan and high-energy alkali-ion batteries. As an essential constituent part, electrode materials with superior electrochemical properties play a vital role in the battery systems. Here, an outstanding electrode of yolk-shell ZnS@C nanorods is developed, introducing considerable void space via a self-sacrificial template method. Such carbon encapsulated nanorods moderate integral electronic conductivity, thus ensuring rapid alkali-ions/electrons transporting. Furthermore, the porous structure of these nanorods endows enough void space to mitigate volume stress caused by the insertion/extraction of alkali-ions. Due to the unique structure, these yolk-shell ZnS@C nanorods achieve superior rate performance and cycling performance (740 mAh g-1 at 1.0 A g-1 after 540 cycles) for lithium-ion batteries. As a potassium-ion batteries anode, they achieve an ultra-long lifespan delivering 211.1 mAh g-1 at 1.0 A g-1 after 5700 cycles. The kinetic analysis reveals that these ZnS@C nanorods with considerable pseudocapacitive contribution benefit the fast lithiation/delithiation. Detailed transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses indicate that such yolk-shell ZnS@C anode is a typical reversible conversion reaction mechanism accomplished by alloying processes. This rational design strategy opens a window for the development of superior energy storage materials. [ABSTRACT FROM AUTHOR]

[Display omitted] The distinctive pomegranate-like Nb 2 O 5 /Carbon@ N -doped carbon (Nb 2 O 5 /C@NC) composites are fabricated using hydrothermal method integrated with nitrogen doped carbon coating procedure. For the SIBs anode, the Nb 2 O 5 /C@NC composites present superior rate character and sustainable capacity (117 mAh g−1 upon 1000 cycles at 5 A g−1). The in-situ X-ray diffraction (XRD) is utilized to research its sodium storage mechanism. Furthermore, for PIBs, the Nb 2 O 5 /C@NC composites present sustainable capacity (81 mAh g−1 upon 1000 cycles at 1 A g−1). The outstanding performance of Nb 2 O 5 /C@NC composites is ascribed to its unique architecture, in which Nb 2 O 5 nanocrystals embedded in porous carbon can restrain agglomeration of Nb 2 O 5 nanocrystals, enhance electron/ion diffusion kinetics, and ensure electrolyte accessibility, and moreover, NC shell layer can provide effective active sites and further increase ions/electrons transfer. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries have ultra–high energy density and are considered to be one of the most promising energy storage systems among all battery systems. However, due to various thorny problems, their commercial production has not yet been realized. The current experimental research normally lacks a systematic investigation into the conversion mechanism of the sulfur cathode from the electronic structure level. Actually, there is still a lack of powerful theoretical guidance for the design of high–performance Li–S batteries and the selection of modified materials still seems blind. In this article, with the chelated Fe‐polyvinyl pyrrolidone as the precursor, a series of Fe–based materials (e.g., Fe3O4@C, FeS@C, Fe3N@C) are synthesized as modified layers for battery separators, and the performance differences between them are systematically studied. It is found that the d–p band center model developed based on the d band center can reasonably combine the reaction potential of Li2S4 and performance differences. Simultaneously, the interaction between Li2S6 and the adsorption interface is simulated by ab initio molecular dynamics. This current work sheds light on promising material design for superior Li–S batteries both from a theoretical and experimental perspective. [ABSTRACT FROM AUTHOR]

Recently, Li‐ion batteries (LIBs) have attracted extensive attention owing to their wide applications in portable and flexible electronic devices. Such a huge market for LIBs has caused an ever‐increasing demand for excellent mechanical flexibility, outstanding cycling life, and electrodes with superior rate capability. Herein, an anode of self‐supported Fe3O4@C nanotubes grown on carbon fabric cloth (CFC) is designed rationally and fabricated through an in situ etching and deposition route combined with an annealing process. These carbon‐coated nanotube structured Fe3O4 arrays with large surface area and enough void space can not only moderate the volume variation during repeated Li+ insertion/extraction, but also facilitate Li+/electrons transportation and electrolyte penetration. This novel structure endows the Fe3O4@C nanotube arrays stable cycle performance (a large reversible capacity of 900 mA h g−1 up to 100 cycles at 0.5 A g−1) and outstanding rate capability (reversible capacities of 1030, 985, 908, and 755 mA h g−1 at 0.15, 0.3, 0.75, and 1.5 A g−1, respectively). Fe3O4@C nanotube arrays still achieve a capacity of 665 mA h g−1 after 50 cycles at 0.1 A g−1 in Fe3O4@C//LiCoO2 full cells. [ABSTRACT FROM AUTHOR]

Ni/C porous nanofibers (NiCPNFs) have been fabricated by electrospinning and a series of subsequent heat treatment cycles. Transmission electron microscope (TEM) and brunauer-emmett-teller measurement (BET) results exhibit that NiCPNFs with a diameter of 300 nm have numerous different size pores. In the meanwhile, nickel nanoparticles (NiNPs) are evenly embedded in porous carbon nanofibers. Moreover, Raman and vibrating sample magnetometer (VSM) results indicate that NiCPNFs possess lower graphitization, lower magnetization (M S) and higher coercivity (H C). The electromagnetic properties of samples show that NiCPNFs have excellent microwave absorbing performance. An absorbing frequency bandwidth with reflection loss (RL) value exceeding −10 dB can reach 12.8 GHz (3.7–12.3 GHz and 13.8–18.0 GHz) when the matching thicknesses are only 2.5–5.5 mm. In addition, the more excellent effective absorbing bandwidth (RL ≤ − 20 dB) reaches 5.4 GHz in the range of 4.2–9.6 GHz. Particularly, the maximum reflection loss (RL) value can reach - 69.5 dB at 7.8 GHz with a thickness of 3.2 mm. Investigations reveal that the participation of porous carbon material in NiCPNFs could obviously improve the microwave absorbing ability of this novel composite material, especially in the C band frequency range (4–8 GHz). • Ni/C porous nanofibers with lower graphitization are fabricated by electrospinning. • Ni/C porous nanofibers show significant improvement in permittivity. • The maximum reflection loss value of NiCPNFs can reach - 69.5 dB at 7.8 GHz. • A good absorbing frequency band (RL ≤ − 10.0 dB) of 12.8 GHz is obtained. [ABSTRACT FROM AUTHOR]

Abstract A hybrid anode based on SnS x composited with reduced graphene oxide (RGO) is the most promising alternative material for the next generation lithium-ion batteries. In this work, we synthesized a novel amorphous SnS x /RGO (a-SnS x /RGO) by a facile hydrothermal method. A-SnS x /RGO exhibits an excellent lithium-ion storage capacity. After 100 cycles the discharge and charge capacity are 562.5 and 546.6 mAhg−1 at a current density of 100 mAg−1. It also exhibits a superior rate performance. When the current density increased to 1000 mAg−1 the reversible capacity was 357.8 mAhg−1. This superior lithium-ion storage performance is attributed to the amorphous structure and the existence of RGO. The amorphous structure could reduce the volume change effect during the discharge and charge process. Graphene with high specific surface area acted as the frame in composite material and can reduce lithium ions' diffusion length and time. What is the most interesting is the existence of strong coupling effect in A-SnS x /RGO which make the interface reaction more faster and more easier. This amorphous material provide a new way for optimizing the cycling stability and improving the rate performance, which is important for the development of high performance electrode materials [ 1 ]. [ABSTRACT FROM AUTHOR]

Well dispersed core/shell structure Fe nanopowders (FeNPs) produced by high energy ion beam evaporation (HEIBE) are added to polyacrylonitrile/N, N-Dimethylformamide (PAN/DMF) solution containing vegetable oil to prepare Fe/C porous nanofibers (FeCPNFs) by electrospinning as electromagnetic microwave absorption material. The FeCPNFs have 3D cross-linked network structure with low graphitization degree. The permittivity and permeability behaviors of the composites made from FeCPNFs and wax are studied in the frequency range of 2.00–18.00 GHz. Mainly due to impedance matching, electric loss, magnetic loss, attenuation constant and “geometrical effect” the FeCPNFs have good microwave absorption properties. The reflection loss (RL) of FeCPNFs can reach − 56.6 dB at matching frequency (4.96 GHz) and matching thickness (4.29 mm). The RL value can also reach −26.1 dB at 11.68 GHz, and effective absorption bandwidth (RL ≤ − 10.0 dB) is 3.00 GHz with a thickness of 2.00 mm. Moreover, under the matching frequency and matching thickness a good absorption performance (RL ≤ − 15.0 dB) from 2.00 GHz to 18.00 GHz is obtained. [ABSTRACT FROM AUTHOR]

The silicon suboxide (SiO) anode material is considered to be a promising anode material of Lithium-ion batteries (LIBs), because of its high theoretical capacity. However, there are severe problems for SiO, including the huge volume change (200%), the low electrical conductivity and the low first Coulombic efficiency. In order to solve those problems, a ternary composite ((SiO x /G/SnO 2)@C) (G denotes graphite) with carbon coating layer is prepared by ball milling, spray drying and sintering. In the composite, graphite as one part of the active materials, can improve the Coulombic efficiency and control volume change of SiO x. To further restrain the high-volume change of SiO x , the carbon coating layer is designed. In particular, owing to the presence of SnO 2 , a better electrochemical performance for (SiO x /G/SnO 2)@C is obtained. The results show that the first charging capacity of (SiO x /G/SnO 2)@C can reach 382.6 mAh g−1 at current density of 100 mA g−1 and the Coulombic efficiency is improved from 62.2% to 74.9%. After 110 cycles, the charging capacity is 424.6 mAh g−1 and the capacity retention rate is 103.9%. In addition, after 90 cycles of rate performance test, (SiO x /G/SnO 2)@C exhibited the highest capacity retention of 104.7%. [ABSTRACT FROM AUTHOR]

Zn-doped AlN nanostructures were synthesized via a catalyst-free chemical vapor deposition method under different growth temperatures. The surface morphologies and size of nanostructures are significantly affected by the growth temperature. The undoped sample shows an ultraviolet emission band at 360 nm, which is attributed to the transition from O N to V A l defect complex to the O N level. With increasing temperature, the doped samples exhibit two new emissions centered at 282 and 320 nm. The band at 320 nm is related to the nitrogen vacancies, and the band at 282 nm can be ascribed to the transition from nitrogen vacancies with three positive charges to neutral Zn acceptors. These results indicate that temperature increase favors the Zn incorporation which strongly affects the growth and luminescence of samples. [ABSTRACT FROM AUTHOR]

Li-S Batteries: Unraveling the Catalytic Activity of Fe-Based Compounds toward Li2Sx in Li-S Chemical System from d-p Bands (Adv. Ab-initio molecular dynamics, catalytic mechanisms, Li-S batteries, separators Keywords: ab-initio molecular dynamics; catalytic mechanisms; Li-S batteries; separators EN ab-initio molecular dynamics catalytic mechanisms Li-S batteries separators 1 1 1 07/19/21 20210715 NES 210715 In article number 2100673, Jun Liu and co-workers use chelated Fe-polyvinyl pyrrolidone as a precursor to synthesize a series of Fe-based composite materials as the modified layer of Li-S battery separators through subsequent simple annealing. [Extracted from the article]

The cathode, a crucial constituent part of Li-ion batteries, determines the output voltage and integral energy density of batteries to a great extent. Among them, Ni-rich LiNixCoyMnzO2 (x + y + z = 1, x ≥ 0.6) layered transition metal oxides possess a higher capacity and lower cost as compared to LiCoO2, which have stimulated widespread interests. However, the wide application of Ni-rich cathodes is seriously hampered by their poor diffusion dynamics and severe voltage drops. To moderate these problems, a nanobrick Ni-rich layered LiNi0.6Co0.2Mn0.2O2 cathode with a preferred orientation (110) facet was designed and successfully synthesized via a modified co-precipitation route. The galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) analysis of LiNi0.6Co0.2Mn0.2O2 reveal its superior kinetic performance endowing outstanding rate performance and long-term cycle stability, especially the voltage drop being as small as 67.7 mV at a current density of 0.5 C for 200 cycles. Due to its unique architecture, dramatically shortened ion/electron diffusion distance, and more unimpeded Li-ion transmission pathways, the current nanostructured LiNi0.6Co0.2Mn0.2O2 cathode enhances the Li-ion diffusion dynamics and suppresses the voltage drop, thus resulting in superior electrochemical performance. [ABSTRACT FROM AUTHOR]