在分层氧化物阴极中氧化晶格氧气的不稳定
Chunjing Hu1, Xiaobing Lou1, Xiang Wu1
1Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China.
ACS nano
|May 10, 2024
概括
高能电池可以使用离子氧化还原,但氧化还原可逆性不太清楚. 这项研究揭示了P3型阴极中的氧气转化和迁移,澄清了更好的电池设计的氧氧还氧控制机制.
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:
- 整合阴离子氧化还原与阴离子氧化还原为高能量密度电池提供了一条道路.
- 对于这些电池来说至关重要的氧氧还原的可逆性问题,源于对氧物种进化的理解不佳.
研究的目的:
- 为了研究P3型Na0.6Li0.2Mn0.8O2阴极中的氧氧还原机制.
- 了解高压操作期间的结构和化学变化.
主要方法:
- 运行电化学分析.
- 在现场进行结构特征分析.
- 理论上的计算理论上的计算.
主要成果:
- 观察到 π 相互作用氧的逐渐转化为 σ 相互作用氧与 O-O 分解和结构重组.
- 鉴定出异常的金属从金属迁移到过渡金属层,导致超结构重建.
- 证明了氧气稳定,而不是上层结构的排序,控制了高压高原.
结论:
- 氧氧氧还原可逆性由氧气稳定机制和π/σ相互作用动力学控制.
- 包括Li+迁移在内的结构变化与氧氧还氧化过程有关.
- 这些发现为设计稳定,高性能的阳离子-氧化电池阴极提供了洞察力.
相关概念视频
Ladder Diagrams: Redox Equilibria
451
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+...
451
Trends in Lattice Energy: Ion Size and Charge
23.9K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
23.9K
Radical Oxidation of Allylic and Benzylic Alcohols
2.0K
Activated manganese(IV) oxide can selectively oxidize allylic and benzylic alcohols via a radical intermediate mechanism. Primary allylic alcohols are oxidized to aldehydes, while secondary allylic alcohols yield ketones. The redox reaction of potassium permanganate with an Mn(II) salt such as manganese sulfate (under either alkaline or acidic conditions), followed by thorough drying, yields the oxidizing agent: activated MnO2. While MnO2 is insoluble in the solvents used for the reaction, the...
2.0K
Oxidation Numbers
37.1K
In redox reactions, the transfer of electrons occurs between reacting species. Electron transfer is described by a hypothetical number called the oxidation number (or oxidation state). It represents the effective charge of an atom or element, which is assigned using a set of rules.
37.1K
Balancing Redox Equations
52.1K
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...
52.1K
Oxidation-Reduction Reactions
64.8K
Oxidation–Reduction Reactions
64.8K


