Shuai Zhu,Xin Wang,Yuhui Li,Xiaochi Lu,Liang Cao,Lei Yu,Zhefei Wang
Novel barium feldspar-based microwave dielectric ceramics derived from graphite tailings (BAS-GT) were prepared via the solid-state reaction method. The effects of Sr 2 + substitution on the phase composition, microstructure and microwave dielectric properties of sintered ceramics were investigated. Results demonstrated that the barium feldspar solid solution co-existed with Ca 2 Al 2 SiO 7 when excess Sr 2+ was introduced. The Sr 2+ substitution effectively improved the densification and microwave dielectric properties of the BAS-GT ceramics, especially the quality factor ( Q × f ) and temperature coefficient of resonant frequency ( τ f ), attributed to the optimised phase composition and good sintering behaviour. A component standard for utilising graphite tailings in microwave dielectric ceramics was established. The 10 mol% Sr 2+ substituted BAS-GT ceramic samples sintered at 1150 °C exhibited optimised microwave dielectric properties, with εᵣ = 7.13, Q × f = 28,452 GHz, and τ f = –27.12 ppm/°C, indicating significant potential of these ceramics for applications in 5 G wireless communication technology.
Kaixuan Bian,Yue Meng,Yulong Fu,Lili Feng,Zhi Wang,Junhao Liu,Xuzhong Gong
Spherical graphite tailings (SGT) as the anode electrode for a lithium-ion battery not only improves the utilization value of SGT as solid waste, but also demonstrates the cleaner production of natural flake graphite (NG) compared with artificial graphite. However, SGT anodes present issues regarding rate performance and cycle stability due to the anisotropy structure and the instability of the solid electrolyte interface (SEI). In this work, a composite anode with isotropic structure was prepared by granulation of high-sulfur coal (HSC) and SGT, while an artificial SEI was prepared utilizing polyether amine/polyvinyl pyrrolidone (PEA/PVP) crosslinked polymer. Results showed that the coke from HSC pyrolysis enhanced the isotropy of the composite anode and improved its rate performance. Compared with SGT, the capacity retention rate of the sample (OSGT-50%OHSC) after oxidation - pyrolysis at a high current density of 5.0 A g−1 increased from 7.2% to 25.8%. Additionally, the PEA/PVP artificial SEI strengthened the cycle stability of the anode. After 1000 cycles, the capacity retention rate increased from 22.5% to 70.3%. The artificial SEI effectively avoided direct contact between the anode and the electrolyte, increasing the initial coulombic efficiency from 70.3% to 77.1%.
危险品化学品经营许可证（带存储）