在Li3RuO4多态体中间隔反应中的回氧中心的定义
Haifeng Li1, Srinivasan Ramakrishnan2, John W Freeland3
1Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States.
Journal of the American Chemical Society
|April 10, 2020
概括
富含的多层氧化物通过氧化还原作用提供更高的离子电池容量. 3RuO4显示可逆间隔和提取,突出显示了先进电池设计中稳定氧气状态的挑战.
科学领域:
- 材料科学
- 电化学
- 能量储存
背景情况:
- 有层的LiMO2阴极限制了电动汽车的离子电池能量密度.
- 超氧化测量可以增加传统过渡金属的氧化还原能力.
- 氧化对这种额外能力的作用尚不清楚.
研究的目的:
- 作为一个模型系统,研究 (Ru) 和氧 (O) 的氧化还原活性.
- 评估Li/Ru对电化学特性的影响.
- 了解丰富材料增加容量的机制.
主要方法:
- 在各种条件下对Li3RuO4进行全面的电化学分析.
- 评估 Li/Ru 的订单效应.
- 涉及过渡金属和氧化物联体的氧化还原活性研究.
主要成果:
- 在2.5V以下,Li3RuO4通过Ru5+/Ru4+氧化还原表现出可逆的Li插入到Li4RuO4.
- 在3.9V时发生无氧提取,主要涉及O状态,并与副作用竞争.
- 高电压提取后的重新插入遵循不同的Ru5+/Ru4+路径,在2.5V以上显示化学歇斯底里,但在随后的循环中可逆.
结论:
- 稳定高度耗尽的O状态,即使是像Ru这样的4d金属,也是一项挑战.
- 材料可以根据结构变化在不同的电位上访问相同的氧化还原对.
- 了解氧化物共价对于设计高容量的存材料至关重要.
相关概念视频
Ladder Diagrams: Redox Equilibria
699
Ladder diagrams are useful tools for understanding redox equilibrium reactions, especially the effects of concentration changes on the electrochemical potential of the reaction. The vertical axis in the redox ladder diagrams represents the electrochemical potential, E. The area of predominance is demarcated using the Nernst equation.
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
699
Redox Equilibria: Overview
1.5K
A reduction-oxidation reaction is commonly called a redox reaction. In a redox reaction, electrons are transferred from one species to another rather than being shared between or among atoms. The reducing agent or reductant is the species that loses electrons and gets oxidized in the process. The species that gains electrons and gets reduced in the process is the oxidizing agent or oxidant. Redox reactions are represented as two separate equations called half-reactions, where one equation...
1.5K
Oxidation-Reduction Reactions
74.7K
Oxidation–Reduction Reactions
74.7K
Redox Reactions
58.0K
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
58.0K
Redox Reactions
758
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
758
Redox Titration: Overview
4.7K
Redox titration is a chemical analysis technique used to determine the concentration of an unknown substance by measuring the electron transfer in a redox (reduction-oxidation) reaction. The process involves gradually adding a titrant with a known concentration of an oxidizing or reducing agent, to the analyte, the solution with an unknown concentration, until reaching the endpoint, which indicates the completion of the reaction between the two substances. Ensuring the analyte is in a single...
4.7K


