With the rapid development of consumer electronics, electric vehicles and energy storage, it is urgent to improve the energy density of secondary energy storage devices represented by lithium-ion batteries. Cathode materials are a key issue to improve the energy density of lithium-ion batteries. Li-rich Mn-based layered oxide cathode materials (LRM) are considered as one of the most promising cathode materials for lithium-ion batteries due to their extremely high theoretical specific capacity (>350 mA·h·g^-1) and reversible specific capacity (>250 mA·h·g^-1). However, the low initial Coulombic efficiency, poor rate performance, and rapid voltage and capacity fading of LRM cathode materials seriously restrict their industrial application. This review introduced the research progress of the crystal structure and electrochemical mechanism of LRM cathode materials, and analyzed the problems of LRM. The modification strategies of LRM cathode materials were comprehensively introduced from the aspects of morphology design control, doping, coating, defect structure design, gradient composition design, layered/spinel heterostructure construction, and electrolyte additives. We provided some ideas and guidance for the future development of LRM cathodes to ultimately promote the practical application of LRM cathode materials.

Natural nano-clay with kaolinite is widely used in photocatalysis. This review represented research progress on the photocatalysis of nanoclay with kaolinite as traditional support, functional support and photocatalyst. A relationship between the structure and photochemical properties of kaolinite was analyzed. In addition, the challenges and future development were also prospected.

Manganese silicate nanomaterials have attracted attention due to their high specific surface area, large pore volume, adjustable pore size and good biocompatibility. Manganese silicate nanomaterials with various morphologies such as hollow nanospheres, solid nanospheres, and core-shell nanospheres are synthesized. Hollow manganese silicate nanomaterials can be applied in cancer diagnosis, cancer therapy, synergistic cancer therapy, etc.. This review mainly introduced the synthesis and applications of manganese silicate nanomaterials. Moreover, the future prospects for development of manganese silicate nanomaterials were discussed.

Precursor continuous silicon carbide (SiC) fiber has a wide application prospect in the fields of aviation, aerospace and nuclear energy. The oxidation behavior and kinetics data of SiC fiber in a high-temperature oxidation environment are rather important for the research of composites. This review summarized the research work on continuous SiC fiber by a precursor method, oxidation type, performance degradation mechanism, oxidation process and oxidation kinetics of SiC fiber, and put forward the future research directions on oxidation behavior of SiC fiber.

Lithium-rich cathode materials have attracted great interests due to their advantages, such as high energy density and wide voltage window. However, their shortcomings like low initial coulombic efficiency and poor cycle performance have hindered their commercial application. Lithium-rich cathode materials Li_1.2Ni_0.13Co_0.13Mn_0.54O_2-xCl_x (x=0, 0.025, 0.050, 0.100) with different molar ratios of chloride ion (Cl^-) doping were prepared by a co-precipitation method. The regulation mechanism of Cl^- doping on the improvement of the electrochemical performance was investigated by X-ray photoelectron spectroscopy, in-situ X-ray diffraction and galvanostatic intermittent titration analysis. Compared with the pristine material, the initial coulombic efficiency of the cathode material with Cl-doping in a molar ratio of 0.05 increases from 72.8% to 81.5% at 0.2 C, and the capacity retention increases from 57.9% to 79.1% after 200 cycles at 1 C. It is indicated that Cl-doping can regulate the electrochemical behavior of O^2- by oxidizing the more into O^n- (n<2) and less production of oxygen gas, thus reducing the structural deterioration. Meanwhile, the larger ion radius of Cl^- can expand the layer spacing, reduce the polarization and accelerate the lithium ions diffusion in the lithium-rich and manganese-based cathode material, thereby enhancing the initial coulombic efficiency and the cycle performance.

Silicon has become the most promising anode material for lithium-ion batteries since its theoretical lithium intercalation capacity is as high as 4 200 mA·h/g. However, its commercial application as a negative electrode for Li-ion batteries is limited due to the huge volume expansion (≥300%) during intercalation and delithiation. In this paper, a C@Si/C silicon-based composite anode was prepared by an electrospinning technique with carbon source precursor coating. The phase structure and microstructure of the material were characterized by X-ray diffraction and scanning electron microscopy. The change of the quality of the obtained material after polyvinypyrrolidone coating with temperature was investigated by thermo-gravimetric analysis. Graphite transformation degree of the silicon-based negative electrode material obtained after carbonization was determined by Raman spectroscopy. The prepared silicon-based anode materials were analyzed by galvanostatic charge-discharge, cyclic voltammetry and alternating current impedance spectroscopy. The results show that the electrochemical performance of the carbon-coated electrospun Si/C fibers is improved compared to the uncoated fibers. At a current density of 0.1 A/g, the first discharge capacity can reach 1 401.4 mA·h/g, the first coulombic efficiency is as high as 70.22%, and the capacity remains at 582.6 mA·h/g after 100 cycles. The results of rate test show that after a large current density test of 1.0 A/g, C@Si/C silicon-based composite anode still has a reversible capacity of 622.2 mA·h/g at a current density of 0.1 A/g.

CH₄ concentration of underground drainage coal mine methane is rather low, which is of the explosion risk and difficult to be used. Therefore, a safe and high-efficiency power generation method of low concentration coal mine methane (LC-CMM) was proposed based on the solid oxide fuel cell (SOFC). The deoxygenation and methane enrichment experiment based on the pressure swing adsorption (PSA) was conducted to eliminate the explosion risk of LC-CMM, the large-scale SOFC single cell experiment using the LC-CMM was carried out, and the multi-physics coupling model of SOFC was developed. The results show that the CH₄ concentration can be increased by 1.36 times, the deoxygenation ratio can reach 84.5% through the PSA experiment, and the produced gas can meet the requirement of safe and efficient power generation of SOFC. The power density of large-scale single cell using LC-CMM can reach 110.2 mW/cm², but the anodic carbon deposition occurs after the long-term discharging, thus causing the SOFC performance degradation. The results of numerical simulation show that the decrease of discharging voltage, the increase of volume ratio between O₂ and CH₄ of fuel and the decrease of fuel inlet rate can decrease the carbon deposition, but reducing the power generation performance of SOFC.

To solve the problem of a narrow pore applicability of zeolite molecular sieves with MFI topology (TS-1), a core-shell mesoporous composite molecular sieve xMCM-41@TS-1 was synthesized by an in-situ crystallization method. The results show that xMCM-41@TS-1 has a well-crystallized microporous core and mesoporous shell with regular pores, thus effectively improving the reaction mass transfer efficiency, reducing the diffusion resistance, and promoting the effective utilization of active titanium centers. Also, the core-shell mesoporous composite structure is beneficial to shortening the diffusion path of the material, so that the carbon deposition precursor in the microporous can diffuse to the surface in time. According to the catalytic performance results, the catalytic activity of xMCM-41-41@TS-1 in butadiene epoxidation and cyclohexane oxidation can reach 3 times and 2 times greater than that of TS-1, respectively, and the cycle stability is greater than that of TS-1.

In order to construct a high-efficiency paper catalysts for soot removal, it is very important to design different active elements and realize the synergistic effects with the matrix fibers. A series of La_1-xK_xMnO₃ (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) nanofiber catalysts were prepared via electrospinning. The oxidation performance of the catalyst for soot particles was examined by temperature programmed oxidation reaction. The defect effects induced by doping K⁺ ions in the LaMnO₃ lattice on their catalytic performance evaluated by soot temperature-programmed oxidation were investigated by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and temperature programmed reduction analysis. The results show that all the nanofiber catalysts have a perovskite structure, while K₂Mn₄O₈ as a new phase appears in the samples as x ≥ 0.3. The amount of active oxygen in the sample is affected by K⁺ ions replacing La³⁺ ions and Mn³⁺ ions transferring into Mn⁴⁺ ions. The replacement of A-site ions increases the degree of oxygen defects in the system, while the transformation of Mn³⁺ ions into Mn⁴⁺ ions determining the number of oxygen vacancies as a new phase can occur at a great content of K⁺ ions doped in the system. The sample La_0.6K_0.4MnO₃ has an optimum catalytic activity at T₅₀ of 347 ℃. The paper-structured catalyst prepared with a nanofiber to matrix fiber ratio of 1∶1 has a good catalytic activity at T₅₀ of 478 ℃.

In the field of catalysis, ZnO nanorods have attracted much attention because of their small size effect in the radial direction and the macroscopic characteristics of bulk materials in the longitudinal direction. In this paper, ZnO nanorods were synthesized by an improved solvothermal method, and Zn²⁺ ions and NaOH were added by a step-by-step method. The samples were characterized by X-ray diffraction and scanning electron microscopy. The mechanism of PEG-assisted synthesis of ZnO nanorods and the effect of NaOH addition on the morphology of ZnO nanorods were investigated. The desulfurization performance of ZnO nanorods with different length to diameter ratios was analyzed. The results show that the molecular weight of PEG has a significant effect on the morphology of ZnO nanorods. ZnO nanorods with a length of 3-4 µm and a diameter of approximately 250 nm can be synthesized under mild solvothermal conditions when the molecular weight of PEG is 20000. Also, the step-by-step method of adding NaOH is better than the one-step method of adding NaOH. NiO is loaded on the synthesized ZnO nanorods as a desulfurizer. The desulfurization rate of ZnO nanorods desulfurizer with a large length to diameter ratio can achieve 98.2%, and the desulfurizer has a better regeneration performance.