在丰富的阴极中运行氧氧回氧过程的磁性
Shiyu Qiu1,2, Jin Bai1, Peiyao Wang1
1Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China.
Advanced materials (Deerfield Beach, Fla.)
|March 20, 2025
概括
研究富含的分层氧化物揭示了氧离子如何储存电荷. 这项研究使用现场磁力来揭示氧氧还氧化机制,这对于设计高能量密度电池至关重要.
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
- 固态化学 固态化学
背景情况:
- 富含的分层氧化物为先进的电池提供高能量密度.
- 这些材料中的氧氧还氧化机制尚未完全理解.
- 了解氧氧还氧化是提高电池性能的关键.
研究的目的:
- 用现场磁性来研究Li1.2Mn0.6Ni0.2O2中的氧氧还氧化机制.
- 为了将磁性和电子结构的演变与电化学循环相关联.
- 为设计高性能阴极材料提供见解.
主要方法:
- 现场磁性测量以跟踪实时磁化变化.
- 电化学循环的Li1.2Mn0.6Ni0.2O2阴极材料的电化学循环.
- 综合的in/ex situ表征和密度函数理论 (DFT) 计算.
主要成果:
- 充电时磁化降低,在4.6V以上显著上升.
- 磁化反弹与不断发展的晶格氧相互作用 (Mn-O到O-O结合) 有关.
- 循环后磁性降低表明不可逆转的结构变化和容量衰减.
结论:
- 这项研究通过in situ磁性阐明了丰富的层状氧化物中的氧氧还原机制.
- 这些发现突出了氧氧还原过程中从π型到σ型结合的过渡.
- 这项研究为开发下一代高能量密度电池材料提供了指导.
相关概念视频
Balancing Redox Equations
51.5K
Electrochemistry is the science involved in the interconversion of electrical and chemical reactions. Such reactions are called reduction-oxidation, or redox reactions. These important reactions are defined by changes in oxidation states for one or more reactant elements and include a subset of reactions involving the transfer of electrons between reactant species. Electrochemistry as a field has evolved to yield sufficient insights on the fundamental principles of redox chemistry and multiple...
51.5K
Electrolysis
25.8K
In a galvanic cell, the electrical work is done by a redox system on its surroundings as electrons produced by the spontaneous redox reactions are transferred through an external circuit. Alternatively, an external circuit does work on a redox system by imposing a voltage sufficient to drive an otherwise nonspontaneous reaction in a process known as electrolysis. For instance, recharging a battery involves the use of an external power source to drive the spontaneous (discharge) cell reaction in...
25.8K
Ladder Diagrams: Redox Equilibria
412
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+...
412
Redox Equilibria: Overview
498
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...
498
Oxidation-Reduction Reactions
64.0K
Oxidation–Reduction Reactions
64.0K
Voltammetry: Factors Affecting Measurements
121
A current produced due to the redox reactions of the analyte at the working and auxiliary electrodes is called a faradaic current. The reaction can be divided into two types. The current generated due to the reduction of the analyte is called cathodic current, and it carries a positive charge. In contrast, the current produced by analyte oxidation is known as an anodic current, and it has a negative charge. The applied potential at the working electrode determines the faradaic current flow, and...
121


