シルバー-ポリオキシメタレートクラスターを用いた電極構造におけるLi-Sの可逆性レドックス反応の探索と開発のための戦略
Jian Chuan Ye1, Jia Jia Chen2, Ru Ming Yuan1
1Department of Chemistry, College of Chemistry and Chemical Engineering, Collaborative Innovation Centre of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University , Xiamen, Fujian 361005, China.
Journal of the American Chemical Society
|February 10, 2018
まとめ
この研究では,リチウム硫黄電池のための新しいAg (I) 置換Keggin触媒を導入しています. 触媒はリチウムポリ硫化物を安定させ,硫黄の高い利用と優れたバッテリー性能を可能にします.
科学分野:
- 材料科学
- 電気化学
- キャタリシス
背景:
- リチウム硫黄 (Li-S) バッテリーは理論的には高いエネルギー密度を持っていますが,ポリ硫黄のシャトルに苦しんでいます.
- リチウムポリ硫化物の安定化は,Li-S電池の性能とサイクル寿命を改善するために不可欠です.
研究 の 目的:
- Li-S バッテリーにおける Li2Sn 分子を安定させるための触媒として,二機能の Ag(I) 置換Kegginポリオキシメタラート (AgPOM) の使用を調査する.
- 硫黄ベースの電極における可逆性酸化還元反応を促進するAgPOMの触媒的活性を探求する.
主な方法:
- Ag ((I)) 置換のKeggin触媒K3[H3AgIW11O39]の合成と特徴づけ
- AgPOMクラスターのLi2Sn分子の吸収を研究するスペクトル検査
- Ag ((I)) と硫黄種間の相互作用を合理化するための密度関数理論 (DFT) の計算.
- AgPOMを組み込んだLi-S電池電極の製造と電気化学試験
主要な成果:
- AgPOMは,強力な吸収によってLi2Sn分子を効果的に安定させ,Ag ((I) はルイス酸のサイトとして作用する.
- DFTの計算は,AgPOMの硫黄種の吸収が強化されたことを確認した.
- AgPOMを使用した電極は,94%の高硫黄利用率と1580mAhg-1のクーロメトリック容量を達成した.
- 複合電極は高い速度で安定したサイクリング性能を示した (1°Cで1050mAhg-1,2°Cで810mAhg-1で100〜300サイクル).
結論:
- AgPOM触媒は,ポリ硫化物を安定させることで,Li-S電池の性能を大幅に向上させます.
- AgPOMの2つの機能は,ルイス酸と塩基触媒の両方として作用し,その有効性の鍵です.
- このアプローチにより,活性硫黄の含有量が高く,硫黄の積もりが高く,安定した高性能のLi-S電池が得られます.
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