Conformally carbon-coated FeP (FeP@C) nanoplates with a porous feature are synthesized by integrating three simple approaches: hydrothermal growth of Fe₂O₃ nanoplates, the spatial introduction of conformal carbon coating, and chemical conversion of an intermediate into FeP by a low-temperature phosphidation strategy. The introduction of carbon coating not only serves as a buttering to effectively prevent the restacking of nanoplates, but also largely improves electrical conductivity and reinforces the structural robustness of FeP. The obtained FeP@C nanoplates show two-dimensional morphology and possess a large surface-area-to-volume-ratio and abundant inner mesopores with a high specific surface area. As an anode of lithium-ion batteries (LIBs), the prepared FeP@C nanoplates exhibit exceptionally high electrochemical performance, which largely outperforms the Fe₃O₄@C counterpart under identical morphological properties in experimental and simulated results. As a result, the FeP@C nanoplates exhibit a reversible specific capacity of 720 mA h g⁻¹ and a capacity retention rate of 96% after 100 cycles at a current density of 200 mA g⁻¹. Even at a higher current density of 500 mA g⁻¹, it still delivers a stable capacity of 610 mA h g⁻¹ within 400 cycles with negligible capacity fading, which opens venues for long life-time applications of LIBs. Furthermore, the superior rate capability of such anodes is also obtained with a reversible specific capacity of 347 mA h g⁻¹ at 5000 mA g⁻¹. The outstanding lithium ion storage properties of the FeP@C nanoplates may be attributed to the reduced energy barrier for the Li storage reaction, shortened electronic/ionic transfer paths, and the physical buffering effect rooted in the rational integration of the phosphide-based species, plate-like nanostructure and conformal carbon surface modification.

A dragon fruit-like nanostructure consisting of ultrafine CoS₂ nanoparticles uniformly encapsulated in N/S-doped carbon polyhedra exhibits outstanding sodium ion storage performance.

FeCl ₃ -intercalated graphite intercalation compounds are developed as stable anodes for optimized lithium storage based on a strong chemical anchoring effect.

Two isotropic pitches were prepared by air blowing and nitrogen distillation methods using ethylene tar (ET) as a raw material. The corresponding carbon fibers were obtained through conventional melt spinning, stabilization, and carbonization. The structures and properties of the resultant pitches and fibers were characterized, and their differences were examined. The results showed that the introduction of oxygen by the air blowing method could quickly increase the yield and the softening point of the pitch. Moreover, the air-blown pitch (ABP) was composed of aromatic molecules with linear methylene chains, while the nitrogen-distilled pitch (NDP) mainly contained polycondensed aromatic rings. This is because the oxygen-containing functional groups in the ABP could impede ordered stack of pitch molecules and led to a methylene bridge structure instead of an aromatic condensed structure as in the NDP. Meanwhile, the spinnability of the ABP did not decrease even though it contained 2.31 wt % oxygen. In contrast, the ABP had narrower molecular weight distribution, which contributed to better stabilization properties and higher tensile strength of the carbon fiber. The tensile strength of carbon fibers from the ABP reached 860 MPa with fiber diameter of about 10 μm, which was higher than the tensile strength of 640 MPa for the NDP-derived carbon fibers.

This study is focused on a novel high-thermal-conductive C/C composite used in heat-redistribution thermal protection systems. The 3D mesophase pitch-based carbon fiber (CF_MP) preform was prepared using CF_MP in the X (Y) direction and polyacrylonitrile carbon fiber (CF_PAN) in the Z direction. After the preform was densified by chemical vapor infiltration (CVI) and polymer infiltration and pyrolysis (PIP), the 3D high-thermal-conductive C/C (C_MP/C) composite was obtained. The prepared C_MP/C composite has higher thermal conduction in the X and Y directions. After an ablation test, the CF_PAN becomes needle-shaped, while the CF_MP shows a wedge shape. The fiber/matrix and matrix/matrix interfaces are preferentially oxidized and damaged during ablation. After being coated by SiC coating, the thermal conductivity plays a significant role in decreasing the hot-side temperature and protecting the SiC coating from erosion by flame. The SiC-coated C_MP/C composite has better ablation resistance than the SiC-coated C_PAN/C composite. The mass ablation rate of the sample is 0.19 mg·(cm⁻²·s⁻¹), and the linear ablation rate is 0.52 μm·s⁻¹.

In this study, three kinds of round-shaped pitch-based graphite fiber with different microstructural features (crystallinity and carbon layer orientation) were fabricated by melt-spinning, preoxidation, carbonization and graphitization. The morphology, crystalline size and carbon layer orientation of carbon fibers from different pitch precursors and spinning rates were characterized through X-ray diffraction, scanning electron microscopy and transmission electron analyses. The correlation of the electrochemical performance and microstructure of graphite fibers as anode materials for lithium-ion batteries was investigated. The results suggest that large-diameter anisotropic graphite fibers (L-AF3000) with a radial texture of the transverse section are more favorable for lithium intercalation storage. The discharge capacity of L-AF3000 is 319.1 mAh∙g⁻¹ at 0.1 C (current density). Nevertheless, the capacity drops to 209.9 mAh∙g⁻¹ at a high current density of 1 C, and the capacity retention is only 82.2% over 100 cycles at 0.1 C. Small-diameter anisotropic graphite fibers (S-AF3000) with a spiral-shaped wrinkle texture of the transverse section possess discharge capacities of 284.1 mAh∙g⁻¹ at 0.1 C and 260.2 mAh∙g⁻¹ at a high current density of 1 C. Meanwhile, the best capacity retention of the fibers is 101.6% over 100 cycles at 0.1 C. The results suggest that the disordered carbon layers in S-AF3000 can retain the structural integrity of fibers as anode material for lithium-ion batteries and thus obtain excellent cycle stability. In addition, larger crystalline sizes of fibers correspond to higher discharge capacity, and a smaller diameter is beneficial to the fast insertion and extraction of lithium-ion in fibers.