自動反応ネットワークによるリチウムエチレン単炭酸の形成メカニズムのデータ駆動予測
Xiaowei Xie1,2, Evan Walter Clark Spotte-Smith2,3, Mingjian Wen4
1Department of Chemistry, University of California, Berkeley, California 94720, United States.
Journal of the American Chemical Society
|August 11, 2021
まとめ
リチウムイオン電池の固体電解質インターフェーズにおけるリチウムエチレン一酸化炭素 (LEMC) の形成は,水の要求によって制限されており,リチウムエチレン二酸化炭素 (LEDC) が主要な有機成分であることを示唆しています. これはバッテリーの性能に影響します.
科学分野:
- 材料化学
- 電気化学
- コンピュータ材料科学
背景:
- 表面膜の反応を特徴づけ,表面膜の進化を予測することは,材料化学における大きな課題である.
- リチウムイオン電池 (LIB) の固体電解質インターフェーズ (SEI) は重要ですが,その構成要素と形成メカニズムについては議論が続いています.
- SEIの構成を理解することは,リチウムイオンエネルギー貯蔵システムの進歩に不可欠です.
研究 の 目的:
- リチウムエチレン一酸化炭素 (LEMC) やリチウムエチレン二酸化炭素 (LEDC) がLIB SEIの主な有機成分であるかどうかを調査する.
- LEMC形成のための新しい反応経路と中間物質を探求する.
- SEIコンポーネントの形成に対する水の存在の影響を評価する.
主な方法:
- 反応ネットワークを用いたデータ駆動の自動化された方法論を利用した.
- 熱力学的反応の景観のために,断片化/再結合によって体系的に関連する種を生成する.
- 密度関数理論 (DFT) の計算と最短経路のアルゴリズムを用いて反応経路を探索した.
主要な成果:
- LiH生成とLEDC結合割れを含む,以前に提案されたいくつかの新しいLEMC形成メカニズムを特定した.
- すべての運動的に有利なLEMC形成経路は,反応物質として水を必要とします.
- 水の必要性はLEMCの形成をLEDCと比較して大幅に制限します.
結論:
- 水がLEMC形成を制限する役割があるため,LEDCはLIB SEIの主要な有機成分である可能性が高い.
- この発見は,リチウムイオンエネルギー貯蔵におけるSEIの形成と性能に直接的な影響を及ぼします.
- このデータベースの枠組みは,表面の受動性を理解するための他の電気化学システムにも広く適用できます.
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