In order to explore the thermal conductivity of polypropylene(PP)/hexagonal boron nitride(BN) composites,PP composites filled with different proportions of BN were prepared through extrution compounding,injection moul...In order to explore the thermal conductivity of polypropylene(PP)/hexagonal boron nitride(BN) composites,PP composites filled with different proportions of BN were prepared through extrution compounding,injection moulding and compression moulding.The composites were filled with BN particles of 5 and 20 μm respectively,and their mass fractions in composites were considered.Percentage of BN was varied from 0 to 25wt% in steps of 5wt%.The effects of BN filler on mechanical properties of the composites were evaluated.The thermal behaviors were studied using DSC and TGA,and the thermal conductivity was also investigated by Laser Flash Device and the Model of 3D Heat Conduction respectively.The experimental results show that impact strength of PP/BN can be enhanced with the addition of BN,but that composites exhibit lower breaking elongation & tensile strength when compared to unfilled ones.It is found that mass fraction of BN influenced the final thermal stability and degree of crystallization of PP matrix,the degree of crystallization of PP with 15wt% of 20 μm BN can be improved by 25% than neat PP.Meanwhile,crystallization temperatures of PP composites are elevated by about 10 ℃.The thermal conductivity results demonstrate that the maximum value of the thermal conductivity is achieved from PP/BN with 20wt% of 20 μm BN,higher than that of pure PP by 95.65%,close to the simulation one.展开更多
钠离子电池(sodium-ion batteries,SIBs)具有成本低的潜在优势,有望成为替代锂离子电池(lithium ion batteries,LIBs)的储能设备。为提升钠离子电池的性能,开发出适应钠离子脱嵌的负极材料尤为重要。硫化锑(Sb_(2)S_(3))因其理论比容量...钠离子电池(sodium-ion batteries,SIBs)具有成本低的潜在优势,有望成为替代锂离子电池(lithium ion batteries,LIBs)的储能设备。为提升钠离子电池的性能,开发出适应钠离子脱嵌的负极材料尤为重要。硫化锑(Sb_(2)S_(3))因其理论比容量高被认为是较好的钠离子电池负极材料。本文使用简单水热法将Sb_(2)S_(3)与石墨烯复合,制备Sb_(2)S_(3)/石墨烯复合材料(Sb_(2)S_(3)/Gr)。结果表明:Sb_(2)S_(3)/Gr作为钠离子电池负极时,不仅表现出良好的电导率(3.5×10~(-3)S/cm)和钠离子扩散速率(4.853×10~(-13)cm~2/s),而且在0.5 A/g的电流密度下,首圈库伦效率为76.27%,经150次循环后的比容量稳定在488 m A·h/g,表现出较高的比容量。Sb_(2)S_(3)/Gr复合材料表现出了极大的应用潜力,为高性能钠离子电池负极材料的研发提供了一定的参考价值。展开更多
基金Funded by the State Grid Henan Electric Power Company Technology Project(No.521790200018)the 2021 Key Scientific Research Projects of Higher Education Institutions in Henan Province(No.21A430047)the Excellent Team Project of Scientific and Technological Innovation in Henan Province(HNST [2017] No.9)。
文摘In order to explore the thermal conductivity of polypropylene(PP)/hexagonal boron nitride(BN) composites,PP composites filled with different proportions of BN were prepared through extrution compounding,injection moulding and compression moulding.The composites were filled with BN particles of 5 and 20 μm respectively,and their mass fractions in composites were considered.Percentage of BN was varied from 0 to 25wt% in steps of 5wt%.The effects of BN filler on mechanical properties of the composites were evaluated.The thermal behaviors were studied using DSC and TGA,and the thermal conductivity was also investigated by Laser Flash Device and the Model of 3D Heat Conduction respectively.The experimental results show that impact strength of PP/BN can be enhanced with the addition of BN,but that composites exhibit lower breaking elongation & tensile strength when compared to unfilled ones.It is found that mass fraction of BN influenced the final thermal stability and degree of crystallization of PP matrix,the degree of crystallization of PP with 15wt% of 20 μm BN can be improved by 25% than neat PP.Meanwhile,crystallization temperatures of PP composites are elevated by about 10 ℃.The thermal conductivity results demonstrate that the maximum value of the thermal conductivity is achieved from PP/BN with 20wt% of 20 μm BN,higher than that of pure PP by 95.65%,close to the simulation one.
文摘钠离子电池(sodium-ion batteries,SIBs)具有成本低的潜在优势,有望成为替代锂离子电池(lithium ion batteries,LIBs)的储能设备。为提升钠离子电池的性能,开发出适应钠离子脱嵌的负极材料尤为重要。硫化锑(Sb_(2)S_(3))因其理论比容量高被认为是较好的钠离子电池负极材料。本文使用简单水热法将Sb_(2)S_(3)与石墨烯复合,制备Sb_(2)S_(3)/石墨烯复合材料(Sb_(2)S_(3)/Gr)。结果表明:Sb_(2)S_(3)/Gr作为钠离子电池负极时,不仅表现出良好的电导率(3.5×10~(-3)S/cm)和钠离子扩散速率(4.853×10~(-13)cm~2/s),而且在0.5 A/g的电流密度下,首圈库伦效率为76.27%,经150次循环后的比容量稳定在488 m A·h/g,表现出较高的比容量。Sb_(2)S_(3)/Gr复合材料表现出了极大的应用潜力,为高性能钠离子电池负极材料的研发提供了一定的参考价值。
