基于Mg的复合化物与多种过渡金属元素的合成和储特性
Evans Pericoli1, Alessia Barzotti1, Raffaello Mazzaro1,2
1Department of Physics and Astronomy "Augusto Righi", University of Bologna, Bologna 40127, Italy.
ACS applied energy materials
|May 2, 2025
概括
基于和过渡金属 (Mg2TMHn) 的新复杂化物显示出有前途的可逆储能能力. 它们的性能取决于Mg/TM比率和过渡金属组成,相隔影响长期稳定性.
科学领域:
- 材料科学 材料科学 材料科学
- 储存气的储存方式
- 固态化学 固态化学
背景情况:
- 基于的复杂化物正在探索用于储应用.
- 过渡金属 (TM) 可以与形成复杂的化物,影响的储存特性.
- 了解Mg2TMHn的合成和储存行为对于开发先进材料至关重要.
研究的目的:
- 通过反应性球磨来合成Mg2TMHn复合化物.
- 研究这些化物的结构和储特性,这些化物具有不同的TM组成和Mg/TM比.
- 评估可逆储能能力,并确定影响性能的因素.
主要方法:
- 在H2压力下通过Mg和TM粉末的反应性球磨合成.
- 使用X射线衍射 (XRD) 进行结构性表征.
- 通过温度编程脱吸 (TPD) 来确定含量.
- 在Sieverts型装置中使用压力组合异热体进行可逆储存评估.
- 使用传输电子显微镜 (TEM) 的微结构分析与纳米级微分析.
主要成果:
- 单个fcc Mg2TMHn化物相 (K2PtCl6型结构) 形成的Mg/TM比为2:1.
- 四角形MgH2也观察到Mg/TM比为3:1.
- 在 3:1 样本中,最大初始含量为 ~5% 的重量.
- 无论TM成分如何,类似的开始脱吸温度,表明Cr或Mn没有显著的不稳定.
- 在测试窗口内,可逆重量计容量为3: 1样品的3.7-4.2重量%,为2: 1样品的3.0-3.2重量%.
- 观察到过渡金属 (特别是Cr和Mn) 的相分离,与可逆容量降低相关.
结论:
- Mg2TMHn复合化物可以通过反应性球磨来合成.
- 可逆储存是通过Mg-MgH2和Mg2TM-Mg2TMHn转换实现的.
- /的比率显著影响可逆容量,3:1的比率显示出更高的性能.
- 过渡金属的相分离是限制长期可逆储能能力的关键因素.
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