单原子催化剂在减少的单层上被吸附,以提高Al-S电池中的动力学
Mukesh Jakhar1, Veronica Barone1
1Department of Physics, Central Michigan University, Mt. Pleasant, MI 48859, USA; Science of Advanced Materials Program, Central Michigan University, Mt. Pleasant, MI 48859, USA.
单原子催化剂显著提高可充电硫电池的动力学和可逆性. 这些催化剂改善了聚硫化物结合,降低了能源障碍,为先进的能源存储铺平了道路.
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:
- 可充电的硫 (Al-S) 电池具有较高的理论能量密度和安全性.
- 缓慢的动力学和不良的可逆性目前限制了Al-S电池的性能.
- 单原子催化剂 (SAC) 显示出改善氧化还原过程和减轻多硫化物穿在AlS系统中的前景.
研究的目的:
- 研究各种单原子催化剂 (Co,Fe,Ir,Ni,Pt,Rh) 在增强Al-S电池的反应动力学方面的潜力.
- 阐明SACs提高Al-S阴极电化学性能的机制.
- 为了确定高性能Al-S电池的最佳SAC基底.
主要方法:
- 密度功能理论 (DFT) 的计算被用来研究SAC,聚硫化物 (Al2Sx) 和基板之间的相互作用.
- 结合能量的分析,放电的自由能量概况,电荷的分解障碍和聚硫化物溶解度.
- 研究电荷转移,键强度和d频段中心,以了解催化机制.
- 基板稳定性和硫承载能力的评估.
主要成果:
- 与裸体表面相比,基于SAC的基板对Al2Sx具有更强的结合能.
- SAC有效地降低了决定速度的放电阶段的能量障碍,并减少了充电期间的分解障碍.
- 通过SAC支持的多硫化物在电解质中溶解率降低.
- Co@基板表现出极好的稳定性,能够适应大量的体积变化,并支持高硫负载 (高达53.37重量%) 而不会发生破裂.
结论:
- 单原子催化剂有效地提高了Al-S电池的动力学和可逆性.
- SAC减轻了聚硫化物穿效应,并提高了整体电化学性能.
- Co@基板为设计高性能Al-S阴极提供了一个有前途的策略.
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