- Address
- 305-0044 茨城県つくば市並木1-1 [アクセス]
研究内容
出版物2004年以降のNIMS所属における研究成果や出版物を表示しています。
所属学会
日本化学会, The Asian Society for Colloid and Surface Science (ASCASS)
ナノアーキテクトニクス材料研究センター
フラーレンベースの新しいナノ多孔質炭素材料の設計
自己組織化,機能性材料,センシング,エネルギー貯蔵,エネルギー変換,生物学的応用
概要
Fullerenes (C60 or C70) are zero-dimensional functional molecules that undergo supramolecular self-assembly due to their high symmetries and extended π-conjugated systems and form various shape-controlled micro- or nanosized crystalline objects. In NIMS, we have developed method to directly convert these highly crystalline π-electron-rich fullerene nanomaterials into hierarchically porous graphitic carbon materials with high surface area and interconnected pore structures by high-temperature carbonization, which have significant potential as electrode materials in state-or-art electrochemical energy storage supercapacitors.
新規性・独創性
Porous carbon materials obtained from fullerene crystals exhibit a unified shape and size followed by superior electrochemical energy storage performance over conventional carbon materials because of their large surface areas, improved electrical conductivities, well-defined pore size distributions, and hierarchical and interconnected pore architectures.
内容
We have recently demonstrated novel hollow carbon spheres with hierarchically porous architectures by high-temperature carbonization of self-assembled fullerene-ethylenediamine hollow spheres (FE-HS). FE-HS were prepared by using a dynamic liquid-liquid interfacial precipitation (DLLIP) method at ambient conditions of temperature and pressure. High temperature carbonization (at 700, 900, and 1100 °C) of the FE-HS yielded nanoporous (micro/mesoporous) hollow carbon spheres with large surface areas (612 to 1616 m2 g-1) and large pore volumes (0.925 to 1.346 cm3 g-1) dependent on temperature applied. The sample obtained by carbonization of FE-HS at 900 °C (FE-HS_900) displayed optimum surface area and exhibited remarkable electrochemical electrical double-layer capacitance properties in aq. 1 M sulfuric acid due to its well-developed porosity, interconnected pore structure, and large surface area. The symmetric supercapacitor cell assembled using FE-HS_900 attained 164 F g-1 at 1 A g-1 with sustained 50% capacitance at 10 A g-1accompanied by 96% cycle life and 98% coulombic efficiency after 10,000 consecutive charge/discharge cycles.
まとめ
Thermal annealing processes disrupt the fullerenes carbon-only skeleton contained within the self-assembled structures, maintaining the basic morphology of the starting material, accompanied by surface roughening and the emergence of a high porosity carbon network essential to enhance the energy storage, conversion, and sensing performance.