阴离子氧化还原是电池研究中的一个热门课题，因为它可以显着提高锂离子电池中富锂阴极的可利用容量。诸如密度泛函理论（DFT）之类的计算方法使人们能够在原子水平上探究局部过程，但仍缺乏系统研究阴离子氧化还原反应的标准方案和工作流程。来自丹麦技术大学的García-Lastra教授团队开发了使用DFT计算研究阴离子氧化还原过程的框架。他们提出的方法能够基于标准DFT计算的数据，来估计循环过程中局部阴离子氧化还原的量和阴离子氧化还原的演变趋势。他们的方法为其它用于理解和设计稳定的富锂材料的计算研究提供了参考。该方案允许人们对给定结构中的阴离子氧化还原物种进行分类，然后进行定量，从而可以进一步研究如何稳定和控制材料中阴离子的氧化还原过程。他们还提出一种预处理方法应用于原始结构的初始集合，以促进过氧化物样物种的形成。预处理方法导致过氧化物类物种数量增加，但是这类物种的存在并不总是在能量上有利，因此必须谨慎考虑结构优化得到的局部能量最小的结构。该文近期发布于npjComputational Materials6: 65 ()。
Editorial Summary
Li-rich compounds：Computational framework for anionic redox process
Anionic redox processes are currently an intensely studied topic in battery research asit allows a significant increase in the accessible energy capacity in Li-rich cathodes in lithium-ion batteries. Computational methods such as density functional theory (DFT) allow one to probe the local processes on the atomic level.Despite such detailed control, standard recipes and workflows for systematic investigations of anionic redox reactions in theoretical calculations are still lacking. A team led by professor García-Lastra at Technical University of Denmark reported a framework for investigating the anionic redox processes using DFT calculations. The presented method is capable of estimating the amount of localized anionic redox and the trends in the evolution of anionic redox during cycling, all based on >npjComputational Materials6:65().
原文Abstract及其翻译
Computational framework for a systematic investigation of anionic redox process in Li-rich compounds (用于系统研究富锂化合物中阴离子氧化还原过程的计算框架)
Alexander Sougaard Tygesen,Jin Hyun Chang,Tejs Vegge&Juan Maria García-Lastra
AbstractAnionic redox processes play a key role in determining the accessible capacity and cycle life of Li-rich cathode materials for batteries. We present a framework for investigating the anionic redox processes based on >xMnO3(1 ≤ x ≤2) structures, with cationic disorder, to identify the evolution of anionic redox processes during cycling. Additionally, we investigate how different choices of exchange-correlation functionals affect the formation of anionic redox species. The preconditioning of the structures is shown to promote the formation of peroxo-like species. Furthermore, the choice of exchange-correlation functional has a large impact on the type of anionic redox species present, and thus care must be taken when considering localization in anionic species.
摘要阴离子氧化还原过程在确定电池富锂正极材料的容量和循环寿命方面起着关键作用。基于标准DFT计算中容易获得的数据，我们提供了一个研究阴离子氧化还原过程的框架。我们的策略包括对不同阴离子种类进行分类的方法、计算结构中存在的物种数量以及促进阴离子氧化还原的预处理方案。该方法应用于一组具有阳离子无序的LixMnO3（1≤x≤2）结构，以识别循环过程中阴离子氧化还原过程的演变。此外，我们研究了不同交换关联函数如何影响阴离子氧化还原物种的形成。结果表明，结构的预处理可促进过氧化物类似物种的形成。此外，交换关联函数的选择对阴离子氧化还原物种的类型有很大影响，因此在考虑阴离子物种中的局域化时必须谨慎。
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