Abstract:

Porous carbon materials have become one research hotspot due to their excellent electrical conductivity, superior stability and low cost. Using phenol, formaldehyde and melamine as raw materials, a high concentration of zinc chloride was used to provide a super-salt environment. After solvothermal reaction, a nitrogen-containing carbon aerogel(NCA) was obtained by pyrolysis at 800℃ in nitrogen. Scanning electron microscope (SEM), Raman and Brunauer-Emmett-Teller (BET) results demonstrate that the NCA sample has hierarchically honeycomb-like structure and its specific surface area reaches 729.6 m2/g. The as-prepared NCA, when tested in three-electrode system as supercapacitor electrode, exhibits a high specific capacitance of 350.7 F/g at 1 A/g and outstanding cycling stability with 97.8 % of the initial capacitance retained after 10000 cycles at 20 A/g in 0.5 mol/L H₂SO₄. Moreover, symmetric supercapacitor based on the NCA electrodes could deliver an impressively high energy density of 26.8 (W·h)/kg at a power density of 800 W/kg. Therefore, NCA is one promising material that can be used in supercapacitors.

Key words: pyrolysis, polymers, nanostructure, carbon aerogel, hypersaline, supercapacitor

摘要：

多孔碳材料因其优异的导电性和稳定性，以及成本低廉等优点而成为当今的研究热点之一。以苯酚、甲醛和三聚氰胺为原料，利用高浓度氯化锌来提供超盐环境，经溶剂热反应后，在氮气中800℃下热解制得了含氮碳气凝胶(NCA)。扫描电子显微镜、拉曼光谱、X射线光电子能谱和氮气吸附等表征结果表明，该含氮碳气凝胶具有分级多孔蜂窝状结构，其比表面积高达729.6 m2/g。采用三电极测试体系测试了含氮碳气凝胶的电化学性能，结果表明，在三电极体系中，以0.5 mol/L H₂SO₄作为电解液，含氮碳气凝胶在电流密度为1 A/g时比电容达到350.7 F/g；在电流密度为20 A/g时，经过10000次充放电后，含氮碳气凝胶的电容保持率仍高达97.8%。在双电极体系中，含氮碳气凝胶在800 W/kg的功率密度下，能量密度可达26.8 (W·h)/kg。上述结果表明，该含氮碳气凝胶是一种非常理想的超级电容器电极材料。

关键词: 热解, 聚合物, 纳米结构, 碳气凝胶, 超盐, 超级电容器