的结构演变 普鲁士蓝模拟在水性ZnSO4电解质中的结构演变
Min Li1, Mariam Maisuradze1, Angelo Mullaliu2
1Department of Industrial Chemistry, University of Bologna, Campus Navile, Via Piero Gobetti 85, Bologna, 40139, Italy.
Small (Weinheim an der Bergstrasse, Germany)
|August 6, 2024
概括
六酸 (MnHCF) 对水性可充电离子电池 (ARZIB) 显示出前景. 这项研究阐明了Zn2+间歇机制,揭示了对电池性能至关重要的结构变化和相位转换.
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
- 储能 储能 储能 储能 储能 储能
背景情况:
- 普鲁士蓝模拟器 (PBA) 对电网规模的储能充满希望.
- 六酸 (MnHCF) 提供了一个独特的开放框架,具有用于离子间隙的双金属位点.
- 在MnHCF中离子 (Zn2+) 间隙的精确机制尚不清楚,这阻碍了电池的开发.
研究的目的:
- 为了全面研究在Zn2+间隔过程中MnHCF的结构和微观演变.
- 为了阐明Zn2+在MnHCF中的动态间歇/释放机制,在局部和远程尺度上.
- 了解MnHCF在水性可充电离子电池 (ARZIB) 中的相位转换行为.
主要方法:
- 同步射线X射线技术,包括X射线光 (XRF) 元素映射和X射线吸收光谱 (XAS).
- 扩展的X射线吸收细结构 (EXAFS) 分析,以探测当地的原子环境.
- 在3米ZnSO4电解质中进行电化学循环,以监测结构变化.
主要成果:
- XRF和XAS证实了MnHCF电极内的Fe,Mn和Zn的元素分布和结构信息.
- EXAFS 分析显示了 Mn 位点的重新排列,包括 Mn─N 键裂和 Mn─O 键形成,这表明协调发生了变化.
- 阶段转换主要发生在第一个循环中,形成合体和立方六酸盐 (ZnHCF) 阶段的混合物.
结论:
- 第一个循环诱导了MnHCF的显著相变,导致稳定的立方ZnHCF的形成.
- 立方 ZnHCF 阶段在随后的循环中表现出极好的电化学稳定性.
- 这项工作提供了对MnHCF中Zn2+间歇机制的详细理解,这对于推进ARZIB技术至关重要.
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