Polymer derived Al-containing silicon carbide (SiC) ceramic fibers as one of the ideal reinforcers for high-temperature ceramic matrix compositeshavesuperiorproperties such as high tensile strength, high modulus, high temperature and oxidation resistance. This review represented development on thepreparation of polymer derived Al-containing SiC ceramic fibers (i.e, synthesis and mechanism of polyaluminocarsilane (PACS), curing method of PACS fibers and controlling defects of Si(Al)C fibers). The advantages and disadvantages of existing PACS synthesis routes and curing processes of PACS fibers were discussed. In addition, this review alsoprospected the future sustainable aspectsto develop new PACS synthesis route and efficient curing method for improving the mechanical properties of Si(Al)C ceramic fibers.

Magnesium slag is a solid waste from the refining process of magnesium metal, facing problems such as low activity and poor volumetric stability. In this study, a CO₂ sequestration fiberboard (CFB) was prepared with magnesium slag and pulp fiber as the raw materials, and the effects of autoclaving curing, carbonation curing and carbonation-autoclaving sequential curing on the properties of CFB and the interfacial microstructure between magnesium slag and pulp fibers were systematically investigated. The results show that the CFB after only autoclaving curing had poor volumetric stability and flexural strength of 4.5 MPa. While the flexural strength and CO₂ uptake of CFB reached 17.3 MPa and 14.4% respectively after 8 hours of carbonation curing. Moreover, the flexural strength of CFB can be further increased to 20.2 MPa by carbonation-autoclaving sequential curing. The microstructure and nanoindentation results show that calcium carbonate crystals, including aragonite and calcite, together with C-S-H filled the pores and enhanced the interfacial micromechanical properties between the pulp fiber and the hardened paste, which is the main reason for the high flexural strength of CFB after carbonation-autoclave curing.

Reaction sintering can effectively reduce the sintering temperature and regulate the properties of porous SiC ceramic membrane supports. This review summarized recent research work on the reaction principle in sintering of porous SiC ceramic membrane support, the type of sintering additives and their mechanisms. The type of solid waste as sintering additives in the preparation of porous ceramic materials was discussed. The existing issues and the future development direction were summarized and prospected, thus providing a guidance for reducing the sintering temperature, cost of porous SiC ceramic membrane supports and recycling of solid waste.

Lithium (Li) metal is considered as the "Holy Grail" anode material for next-generation high-energy density battery system due to its high theoretical capacity and lowest reduction potential. However, the practical application of Li metal anodes (LMAs) is still impeded due to its intrinsic issues, including the uncontrolled Li dendrites growth, unstable solid-electrolyte interface (SEI), and the accumulation of "dead Li". The fluorinated materials can stabilize the Li/electrolyte interface, lead to the uniform Li flux and suppress the growth of Li dendrites, thus becoming one of the research hotspots for LMAs. This review summarized recent progress of the fluorinated inorganic materials on constructing Li metal plated skeletons, developing artificial SEI film, introducing electrolyte additives and employing solid-state electrolytes. The rational design and mechanism of these reported fluorinated inorganic materials for stabilizing LMAs were represented. In addition, we also prospected the future research aspects.

Some environment-friendly and renewable energies are used since the existing problems for energy shortage and environmental pollution are needed to be solved. Hydrogen energy is one of widely used secondary energies with a rich source and low carbon emission, which can be used as a complement to electric/thermal energy, forming a modern energy supply system with a diversified complementary integration. However, hydrogen technology started late in China, and some key materials of water electrolyzers and fuel cells in the hydrogen-electricity energy conversion devices are imported, which is urgent to complete the domestic substitution. Inorganic nonmetallic materials feature a high chemical/electrochemical stability, high strength, and high-temperature resistance. This review represented research progress and highlights in catalysts/supports, ion exchange membranes, carbon-based diffusion layers, graphite bipolar plates, and hydrogen-electricity energy conversion devices. In addition, some problems in the development of novel materials for hydrogen/electric energy conversion were also given, and the future research directions were prospected.

Solid amine adsorbents have broad application prospects in CO₂ capture. However, most of solid amine adsorbent support materials are ordered mesoporous materials, which restrict the industrial application, due to their shortcomings (i.e., complex synthesis process, high cost and great environmental pollution). In recent years, solid waste derived solid amine adsorbents have attracted extensive attention because of their potential cost advantage in support materials. This review summarized recent research progress on solid waste derived support materials in raw material selection, support material synthesis and pore expansion, as well as the preparation of solid waste derived solid amine adsorbents, their adsorption performance and cyclic stability applied in CO₂ capture. In addition, some challenges of solid waste derived solid amine adsorbents were also discussed, and their development trends were prospected as well.

Selenides have a higher reversible capacity and a suitable working potential. However, their large volume change during cycling and low conductivity restrict their practical applications. In this paper, FeSe₂/Ti₃C₂T_x composites were synthesized as anode materials for sodium-ion batteries by a simple hydrothermal method. Fe²⁺ were firstly coordinated with ethylene diamine tetraacetie acid to form chelates, and then FeSe₂/Ti₃C₂T_x composites were synthesized via the electrostatic interaction between Ti₃C₂T_x and Fe²⁺ chelates after the hydrothermal reaction. FeSe₂/Ti₃C₂T_x has an open 'flower petal' structure, and Ti₃C₂T_x in the composite provides an intense conductive network for the material and relieves volume expansion. According to the results of the electrochemical test, Ti₃C₂T_x electrode has a capacity of 455 mA·h/g after 150 cycles at 0.5 A/g, while the capacity of FeSe₂ electrode at the same current density is only 335 mA·h/g after 100 cycles, and the capacity decays rapidly in the subsequent cycles. It is indicated that FeSe₂/Ti₃C₂T_x electrode has superior electrochemical sodium storage performance and cycling stability.

Graphitic carbon nitride (g-C₃N₄) is a typical sp² π conjugated polymer semiconductor material with a variety of unique physical and chemical properties. However, g-C₃N₄ obtained by a conventional calcination method has some shortcomings such as small specific surface area, a few exposed active sites, and a poor dispersibility in aqueous solution, restricting its practical application. Compared with bulk g-C₃N₄, g-C₃N₄ nanosheets obtained by different exfoliation processes have attracted much attention in the fields of energy, catalysis and sensing due to their high specific surface area, short carrier path, abundant active sites and large band gap. g-C₃N₄ has some disadvantages of nanosheet agglomeration, high energy consumption, long time consumption and low yield in the exfoliation preparation process. It is thus necessary to develop a green and cost-effective method for the preparation of g-C₃N₄ nanosheets. This paper reviewed the exfoliation mechanisms of top-down liquid exfoliation, chemical exfoliation and thermal exfoliation. The structure, composition, lamellar thickness and specific surface area of g-C₃N₄ nanosheets obtained by three methods were compared. In addition, some applications in photocatalysis were introduced, and the future development of g-C₃N₄ nanosheets was also prospected.

The double perovskite oxides are widely investigated as cathode materials for solid oxide fuel cell (SOFC) due to their superior ionic electron conductivity. In this work, Pr_0.9Ca_0.1Ba_1-xCa_xCo₂O_5+δ (0≤x≤0.3, PCBC) was prepared by a modified complexing sol-gel process. Based on the electrical conductivity results, Ca ion co-doping can effectively improve the conductivity of the material. The electrochemical performance results indicate that the cathode with x of 0.2 has the optimum oxygen catalytic activity, and the polarization impedance is only 0.069 Ω·cm² at 700 ℃. The oxygen vacancy formation energy, density of states, as well as O s and O p band center of PrBaCo₂O_5+δ, Pr_0.75Ca_0.25BaCo₂O_5+δ, and Pr_0.75Ca_0.25Ba_0.75Ca_0.25Co₂O_5+δ materials were calculated based on the GGA-PBE function. It is indicated that Pr-site doped with Ca can reduce the oxygen vacancy formation energy, while Ba-site doped with Ca can increase the oxygen vacancy formation energy. The calculation results of O p band center show that the strategy of Ba-site doped with Ca can effectively increase the oxygen reduction activity. The co-doping strategy of double perovskite can improve the thermal expansion, conductivity, electrochemical performance, and long-term stability of the material.

The applications such as electric vehicles require a high energy density in lithium-ion batteries. LiNi_0.9Co_0.1O₂ has attracted much attention, which has a potential to be next-generation cathode material due to its high specific capacity and reasonable cost. However, some related issues such as Li/Ni mixing, microcracks and surface side reactions caused by H2-H3 phase transformation result in a poor cycling stability for LiNi_0.9Co_0.1O₂. In this paper, the microstructures of LiNi_0.9Co_0.1O₂ by W⁶⁺ doping were regulated by an effective method to adjust the surface energy of the primary particles and transform the disordered and irregular-shape primary particles into the well-ordered radially-aligned elongated shape particles. This microstructure feature can suppress the stress accumulation and the formation of micro-cracks in LiNi_0.9Co_0.1O₂, and provide abundant diffusion channels for Li⁺, thus improving the cycling stability and rate performance of LiNi_0.9Co_0.1O₂ cathode materials. The discharge capacities of 1% (in mole fraction) W-doped LiNi_0.9Co_0.1O₂ are 231.2 mA·h/g at 0.1 C and 213.3 mA·h/g at 0.5 C, respectively, with a high capacity retention of 93% after 150 cycles. This microstructure regulation strategy provides an effective approach for improving the cycling stability of LiNi_0.9Co_0.1O₂ Ni-rich cathode materials.