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Lithium-rich layered oxide materials (LLOs) are widely studied due to its high reversible capacity. However, the stability during cycling and initial coulombic efficiency should be improved. Herein, we applied ball milling based facile calcination modification methods by combining doping fluorine and coating with Al 2 O 3 to synthesis modified Li[Li 0.20 Ni 0.133 Co 0.133 Mn 0.534 ]O 2 cathode materials for lithium-ion batteries. Characterization results of XRD, SEM and TEM show that fluorine doping could largely stabilized materials structure. Al 2 O 3 coating is proved to improve LLOs' stability during cycling. The formation of Al-F-O-H type species proved by X-ray photoelectron spectra lead to improved discharge capacity and cycle performance. This work provides insight on the cost-effective production of high quality LLOs and helps determine appropriate modifications to improve the commercial utilization of LLOs. [ABSTRACT FROM AUTHOR]

• Symmetrical W/Si3N4/W functionally graded materials (FMGs) were fabricated. • The layer numbers and MgO content affected the structure and thermal stress of FGMs. • The W/Si3N4/W FGMs exhibited high flexural strength and electrical resistivity. • The W/Si3N4/W FGMs can be used as sealing materials of liquid metal batteries. [Display omitted] Si 3 N 4 ceramics have shown promising application prospects as the sealing materials for liquid metal batteries (LMBs). However, the joining of Si 3 N 4 to the metal shell of LMBs is rather difficult because of the non-wetting property and mismatch of their thermal expansion coefficients (CTEs). Herein, to solve the above issue, W/Si 3 N 4 functionally graded materials (FGMs) were designed and fabricated via the spark plasma sintering (SPS) process. The effects of layer numbers and layer components on the phase composition, structure, and thermal stress of the FGMs were systematically investigated using both experimental and simulation methods. W/Si 3 N 4 FGMs, with optimal layer numbers, were then utilized for fabricating symmetrical W/Si 3 N 4 /W FGMs. The thermal stress of the products can be effectively reduced by adjusting the MgO content of the central Si 3 N 4 layer. As a result, the optimal product displayed good interface bonding between two adjacent layers and also exhibited high flexural strength (943.9 MPa) and electrical resistivity (2.0 × 1012 Ω cm). This route for the fabrication of symmetrical W/Si 3 N 4 /W FGMs exhibits the advantage of high efficiency, and the products with excellent properties can be used as sealing materials for LMBs. [ABSTRACT FROM AUTHOR]

As a widely used electrode material, carbon cloth possesses the advantages of a stable self-supporting structure and fast electron conduction rate. Sodium vanadate has gradually attracted the attention of researchers owing to its unique layered tunnel-like structure. In this work, in-situ growth of NaV 6 O 15 on carbon fiber with a 3D porous tunnel-like structure for cathode material of aqueous zinc ion batteries is reported. NaV 6 O 15 nanorods are uniformly dispersed on the surface of carbon cloth fibers and coated perfectly, which intertwined to form rich 3D porous tunnels. The as-prepared NaV 6 O 15 @C has a reversible capacity of 487.7 mAh·g−1 at 0.1 A·g−1, which is 2.6 times that of pure NaV 6 O 15 -A. The coulomb efficiency (CE) is always maintained at 100 %, which proposed a scheme for the design of higher capacity cathode materials. • Carbon cloth coated by NaV 6 O 15 nanorods was designed for zinc ion battery cathode. • NaV 6 O 15 @C shows a 3D tunnel structure and provides a rich adsorption site. • NaV 6 O 15 @C has a high specific capacity, which is 2.6 times that of pure NaV 6 O 15. [ABSTRACT FROM AUTHOR]

The study of infrared stealth-compatible, electromagnetic wave-transparent technology is currently receiving a lot of attention due to the functional specificity of the equipment, such as radomes. In this study, a new method of layered spraying was used to construct three-layer composite coatings, in which each layer was sprayed with a different formulation of paint. By adjusting the content of aluminum powder in each layer and keeping the content of carbon fiber (CF) at 4 wt%, the three-layer composite coatings achieved a balance of dielectric property, antistatic performance, and low infrared (IR) emissivity. The A3-A0-A0 composite coating, which matched the parameters for low IR emissivity and low dielectric property, had an IR emissivity of 0.498, a dielectric constant at 9.375 GHz of 6.23, and a dielectric loss of 0.038. The findings demonstrate that the aluminum powder content of the topmost layer had the sole significant impact on the three-layer composite coatings' IR emissivity, although the dielectric constant was strongly associated with the coating's overall aluminum powder content. The novel three-layer composite coating offers a brilliant concept for the study and development of materials that are compatible with wave transmission and infrared stealth. • A unique layering spraying procedure was used to make three-layer composite coatings. • The infrared emissivity depends on the amount of aluminum powder at the top. • Dielectric constant is correlated with the coating's overall powder concentration. • Low IR emissivity and wave transmission compatibility were attained. • Excellent performance, affordable, and easy to prepare. [ABSTRACT FROM AUTHOR]

With the increasing utilization of microwaves in the gigahertz range, the preparation of high-performance microwave absorbing materials is technologically essential. In this research, porous carbon and iron composites derived from iron metal-organic frameworks (Fe-MOFs) were easily synthesized via solvothermal reactions and in situ pyrolysis processes. The porous carbon matrix and iron create a synergistic effect of dielectric loss and magnetic loss, which optimizes the impedance matching and improves the microwave absorbing performance. When the matching thickness is only 1.5 mm, the reflection loss and the effective absorbing bandwidth reach − 37.63 dB and 4.4 GHz, respectively. Meanwhile, It's worthwhile to explore MOFs-derived carbon-based composite absorbers with high room for improvement. This research provides a new method for the preparation of high-performance microwave absorbing materials with thin thickness. • The Fe/C composite derived from Fe-MOFs was prepared successfully. • The porous structure and the synergy of dielectric and magnetic loss contribute to microwave absorption. • The RL min of FC-900 reaches − 37.63 dB when the matching thickness is only 1.5 mm, and the effective absorption bandwidth reaches 4.4 GHz. • Multiple attenuation mechanisms of the Fe/C composite are clarified. [ABSTRACT FROM AUTHOR]