Biomass is an ideal source for the preparation of electrode materials due to its abundant distribution, renewability, and low price. Carbon materials constructed by nitrogen doping can greatly improve the performance of electrode materials, provide additional pseudocapacitance, and expand the application of supercapacitors in practice. Nitrogen-doped walnut shell (WS) carbon materials were prepared by chemical cross-linking and KOH activation using WS and gamma-polyglutamic acid as raw materials. The effects of the ratio for carbon and nitrogen source compounds and activation temperature on the morphology, pore structure, graphitization of the carbon materials, and their electrochemical properties were systematically investigated. Nitrogen-doped WS carbon materials possessed a unique 2D lamellar structure and a high specific surface area (1932 m(2) g(-1)). The addition of heteroatoms increased the polarizability and conductivity of the carbon material and introduced additional pseudocapacitance as a result of the good electrochemical performance. At a current density of 0.5 A g(-1), the specific capacitance of materials can reach 342.0 F g(-1) with a capacitance retention rate of 73% (20 A g(-1)). After 8000 cycles, the capacitance loss is only 8%, providing excellent electrochemical performance.

能源枯竭和环境污染问题日益严重,新型可持续能源的开发迫在眉睫.超级电容器作为电化学能量存储设备,具有容量大、功率密度高、循环寿命长等优势,逐渐成为研究热点.纤维素是自然界中广泛存在的一种天然高分子化合物,具有绿色、环保、可持续、成本低的特点,制备的碳材料有独特的孔结构和大的比表面积,使其在超级电容器方面的应用成为一个主要研究方向.通过对碳材料的孔结构调控和表面改性,或与电容较高的其他材料进行复合,可以明显提高碳材料比电容和能量密度,使超级电容器电化学性能提高.本文总结了近年来国内外纤维素基碳材料制备方法、性能调控及其在超级电容器方面的应用进展.最后,对纤维素基碳材料未来的研究方向和发展进行了展望.

Novel composites with excellent mechanical properties were prepared by polyether polyurethane( PEU) and silver nanoparticles/polyurethane( nmAg@ PU). The composites were investigated through Fourier Transform Infared Spectroscope( FTIR),UV-vis Spectrum,Thermal Gravity Analysis( TGA),Transmission Electron Microscopy( TEM) and Differential Scanning Calorimetry( DSC). The results indicated that the composites had good thermostability and silver nanoparticles was attached covalently on the composites without obvious agglomeration. In addition,the degree of microphase separation of the composites had little difference with PEU. In summary,the material had the potential applied to the field of biomedical materials.