酸素・レドックスから硫黄・レドックス:リチウム豊富な層状カソッドのパラダイム
Jing-Chang Li1,2, Jiayi Tang1, Jiaming Tian1,2
1College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, National Laboratory of Solid State Microstructures, Collaborative Innovation Centre of Advanced Microstructures, Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210093, P. R. China.
Journal of the American Chemical Society
|February 20, 2024
まとめ
硫黄ベースのホストは,層構造を安定させることで,リチウムイオン電池のエネルギー密度を大幅に高めます. このアプローチは酸素ベースの材料の限界を克服し,バッテリーの性能を改善するために耐久性のあるアニオン酸化還元化学を可能にします.
科学分野:
- 材料科学
- 電気化学
- バッテリー技術
背景:
- リチウムの豊富な層の酸化物におけるアニオンリドックス化学は,リチウムのイオン電池のエネルギー密度を高めます.
- 酸素基のホストは,TM-O結合のイオン性により,構造的再配置と移行金属 (TM) イオン移動などの課題に直面しています.
研究 の 目的:
- 硫黄ベースのホストをリチウム豊富なカトドのフレームワークの安定化のための固有のソリューションとして提案し,検証する.
- 硫黄酸化還元過程における格子歪みのバッファリングを調査し,構造的整合性を改善する.
主な方法:
- フレームワークの安定性を高めるために,強いTM-S共性を持つ硫黄ベースのホストを使用した.
- リチウム濃度の高い硫化カトドの実験サイクルを実施した.
- イオン軌道を分析するために高次元のニューラルネットワークポテンシャルを使用して大規模な分子動力学シミュレーションを行った.
主要な成果:
- Li+の抽出/挿入中にハネコブの超網を含む層状の硫黄網の長期保存が実証されています.
- リチウム濃度の高い硫化カトドで優れた電気化学性能を達成し,過小電位 (0.08V) と最小の電圧低下 (0.13mV/サイクル) を示した.
- シミュレーションにより,酸素と比較して,硫黄イオンの軌道が著しく短くなることが明らかになった.
結論:
- 硫黄ベースのホストはホストのフレームワークを効果的に安定させ,酸素ベースの材料で見られる問題を克服します.
- 強いTM-S共性と短いイオン拡散経路は,優れた電気化学性能と耐久性に寄与する.
- 耐久性アニオン酸化還元化学のための安定化フレームワークの重要性を強調し,先進的なリチウム豊富なカソッドの設計のためのガイドラインを提供します.
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