単壁カーボンナノチューブで並べてパックされたイオン拡散と電気化学容量
Ali Izadi-Najafabadi1, Don N Futaba, Sumio Iijima
1Nanotube Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8565, Japan.
Journal of the American Chemical Society
|December 15, 2010
まとめ
配列炭素ナノチューブは,構造に並行して急速なイオン拡散を可能にし,活性炭を大幅に上回ります. このアニゾトロピックイオン輸送は,特に高い放電速度で,電気化学コンデンサの性能に影響します.
科学分野:
- マテリアルサイエンス 材料科学
- 電気化学 電気化学について
- ナノテクノロジー ナノテクノロジー
背景:
- イオン拡散は,電気化学的エネルギー貯蔵装置にとって非常に重要です.
- 炭素ナノチューブは,強化されたイオン輸送のためのユニークな構造特性を提供します.
- ナノ材料におけるアニゾトロプ的拡散は,デバイスの性能に影響を与える可能性があります.
研究 の 目的:
- 調整された単壁カーボンナノチューブ (SWCNT) 電極でイオン拡散係数を直接測定する.
- SWCNTにおけるイオン拡散のアニゾトロピック性について調査する.
- 電気化学電容器の性能に対するアニゾトロプ的拡散の影響を評価する.
主な方法:
- 配列されたSWCNT電極内のアセトニトリル中のKSCNを用いたイオン拡散の直接測定.
- イオン拡散係数をSWCNT並列と垂直に比較する.
- 電気化学コンデンサのSWCNT電極の性能評価,異なる放電速度で.
主要な成果:
- 調整されたSWCNTに並行したイオン拡散は,理論的な限界に近い速度,活性炭の20倍 (1 × 10−5 cm2/s vs 5 × 10−7 cm2/s) を達成しました.
- SWCNTsに垂直したイオン拡散は,著しく遅かった (8 × 10−7 cm2/s).
- 電気化学コンデンサは低速で同様の性能を示したが,垂直方向のコンデンサは,高速のパラレル方向の14%に対して66%の容量低下を示した.
結論:
- ラインナップされたSWCNTは,非常に効率的なアニゾトロピックイオン輸送を促進します.
- 電極内のSWCNTの方向性は,電気化学装置の性能,特に電力密度および容量保持に決定的な影響を及ぼします.
- ナノチューブのアライメントを最適化することは,SWCNTベースのエネルギー貯蔵システムの可能性を最大化するために不可欠です.
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