在金属有机框架中设计基非桥接位,以提高储能
Lanju Sun1,2, Chongzhi Zhu3, Lukun Li2
1Qingdao Engineering Research Center of Agricultural Recycling Economy Materials, College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, 266109, Qingdao, China.
Angewandte Chemie (International ed. in English)
|November 11, 2024
概括
在金属有机框架 (MOF) 中引入非桥梁缺陷可以显著提高它们在离子电池 (LIB) 中的性能. 这种缺陷工程方法提高了存储能力和速率性能,为先进的电池技术铺平了道路.
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
- 纳米技术 纳米技术
背景情况:
- 金属有机框架 (MOF) 显示出对储能应用的前景.
- 在离子电池 (LIB) 中使用MOFs有限,因为完全协调阻碍了离子运输.
- 在MOF中缺陷工程是一种新兴的策略,用于定制材料属性.
研究的目的:
- 调查MOF中非桥梁缺陷部位对储存性能的影响.
- 阐明这些缺陷在增强 LIBs 的电化学性质中的作用.
- 为了比较缺陷工程MOF与原始MOF的性能.
主要方法:
- 使用同源配体合成原始MOF (p-MOF) 和缺陷工程的MOF (d-MOF).
- 使用光谱和冷低剂量电子显微镜进行表征,以识别和分析缺陷部位.
- 密度函数理论 (DFT) 计算以建模Li+在缺陷部位的吸附和迁移.
- 电化学测试用于评估储能和速率性能.
主要成果:
- 验证了d-MOF中非桥梁缺陷点的存在和局部结构.
- DFT的计算显示,在非桥接地点增加了+吸附和降低了迁移障碍.
- 与p-MOF相比,d-MOF显示出更高的储能 (761 mAh g-1 在0.05 A g-1)
- d-MOF表现出极好的速率性能 (203 mAh g-1 在5 A g-1).
结论:
- MOF中的非桥梁缺陷点在量身定制存储性能方面发挥着至关重要的作用.
- MOFs的缺陷工程为开发高性能LIB提供了一个可行的策略.
- 这种方法在LIB应用中显著优于传统的MOF结构.
相关概念视频
02:51Metal-Ligand Bonds
20.6K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
20.6K
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
343
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
343
00:43Complexometric Titration: Ligands
916
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
916
02:58Crystal Field Theory - Octahedral Complexes
26.2K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.2K
01:19Complexation Equilibria: The Chelate Effect
463
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
463
00:56Extraction: Advanced Methods
425
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
425