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固い炭素アノドにおける局所構造とナトリウム貯蔵の相関:ペア分布関数解析と固体NMRからの洞察

  • 0Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, U.K.
Journal of the American Chemical Society +

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2021年8月25日

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2021年8月25日

PubMedで要約を見る

まとめ

この要約は機械生成です。

この研究は,ナトリウムイオン電池の硬い炭素にナトリウムイオンがどのように蓄積されているかを明らかにしています. メタリックナトリウムクラスターは欠陥領域で形成され,地元の原子構造と合成条件に基づいてバッテリーの容量に影響を与えます.

科学分野

  • 材料科学
  • 電気化学
  • 固体化学

背景

  • 硬い炭素はナトリウムイオン電池のアノド材料として有望である.
  • 硬い炭素のナトリウムイオン貯蔵の正確なメカニズムは完全に理解されていません.

研究 の 目的

  • 固い炭素でナトリウムを貯蔵する局所的な原子環境を解明する.
  • 硬い炭素アノドでのナトリウム貯蔵のメカニズムを修正する.
  • 硬い炭素の微細構造とナトリウム貯蔵能力を相関させるため

主な方法

  • オペラントとex situペア分布関数 (PDF) の総分散データ解析
  • 23Na固体核磁気共振 (NMR) スペクトロスコーピーを操作する.
  • 熱分解温度に基づく局所的な炭素構造のモデル化

主要な成果

  • 硬い炭素構造は,曲ったグラフェン二層で構成され,断片のサイズと曲線は,熱分解温度に依存する.
  • 高い電圧の容量は欠陥の濃度と相関し,低い電圧の容量はより大きな断片サイズに関連しています.
  • ナトリウムイオンは,より高い電圧で欠陥炭素領域の近くに貯蔵され,より低い電圧で金属ナトリウムクラスター (13−15 Å) を形成します.

結論

  • 局所的な原子構造は,硬い炭素のナトリウム貯蔵能力を大きく左右する.
  • クラスターの大きさではなく,ナトリウムクラスターの形成が,低電圧容量を決定する.
  • 硬い炭素アノドの最適化には,局所的な原子と微細構造を制御するための合成条件を慎重に考慮する必要があります.

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