通过合理的p-π结合法规实现缺电子的中心,用于高性能Li-S电池
Mai Li1, Hui Liu1, Huifang Li1
1College of Electromechanical Engineering, Shandong Engineering Laboratory for Preparation and Application of High-Performance Carbon Materials, Qingdao University of Science & Technology, Qingdao, 266061, P.R. China.
Angewandte Chemie (International ed. in English)
|March 25, 2025
概括
碳纳米管上的缺电子单原子催化剂 (SAC) 提高硫 (Li-S) 电池的性能. 这种设计改善了聚硫化物结合和催化活性,使得使用精益电解质的高能量密度电池成为可能.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 催化剂是一种催化剂.
背景情况:
- 单原子催化剂 (SAC) 对于提高硫 (Li-S) 电池性能至关重要.
- 在金属工厂周围的协调环境的合理设计是优化SAC的关键.
- 高负载和瘦电解质条件对Li-S电池构成重大挑战.
研究的目的:
- 在碳纳米管 (CNT@f-CoNC) 上设计和合成缺电子单原子催化剂 (SACs),增强易斯酸度.
- 研究独特的协调环境对聚硫化物化学吸收和催化活性的影响.
- 在苛刻的条件下评估Li-S电池中设计的SAC的电化学性能.
主要方法:
- 在易斯的酸理论的启发下,在碳纳米管上构建了缺电子的Co SAC.
- 对聚硫化物的结合亲和力和硫还原反应的能量屏障与类Co SACs进行了比较.
- 电化学性能测试使用高硫负载 (6.9 mg cm−2) 和瘦电解质与硫 (E/S) 比率 (4.0 μL mg−1) 进行.
- 为了展示实际应用,组装了一个1.6Ah级袋式电池.
主要成果:
- 与类Co SAC相比,缺乏电子的Co SAC对聚硫化物 (路易斯基) 具有更强的结合亲和力.
- 观察到硫还原反应中速度决定阶段的能量屏障明显较低.
- 在高硫负载和电解质条件下,实现了7.7 mAh cm-2的面积容量.
- 组装的袋式电池提供了422Wh kg-1.1的高能量密度.
结论:
- 缺乏电子的Co SAC的合理设计显著提高了Li-S电池的电化学性能.
- 通过协调环境设计调节金属站点的局部电子密度是一个有希望的策略.
- 这种方法使得高性能Li-S电池,即使在高硫负载和稀缺电解质条件下.
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