Redox, Magnetic, and Structural Properties of α-NaMnO2 Cathode Material Analyzed by Fitting-Free DFT+U Calculations, Parameterized by the Linear Response Approach
Redox, Magnetic, and Structural Properties of α-NaMnO2 Cathode Material Analyzed by Fitting-Free DFT+U Calculations, Parameterized by the Linear Response Approach
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通过免拟合 DFT+U 计算分析 α-NaMnO2 阴极材料的氧化还原、磁性和结构特性，并通过线性响应方法参数化
DOI：
10.1021/acs.jpcc.0c09344
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Sato Hirofumi
中科院分区：
文献类型：
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作者：
Shishkin Maxim;Sato Hirofumi
评价碱离子电池阴极的电化学性能，使其与实验测量结果保持良好的一致性，同时避免经验拟合，是材料科学中一个非常理想的目标。本文采用DFT+ U方法，采用线性响应方法参数化计算了α-NaMnO_2阴极材料的电压分布。我们的计算揭示了一个改进的协议与实验电压曲线相比，DFT+ U计算与拟合和fixedU参数，特别是高电压。此外，我们还分析了如何磁有序的NaMnO 2的脱嵌过程中的变化时，Na电荷载流子被删除，导致本体的Mn阳离子的氧化态的变化。我们表明，反铁磁有序，实验观察到的NaMnO 2和LiMnO 2，确实对应于较低的能量与铁磁有序的变化后，去除40-50%的Na离子或更多。以前确定的配置NaxMnO 2（使用实验和理论方法）的分析也表明了数值评估的重要性theU参数与实验结果更好地吻合。
Evaluation of electrochemical properties of cathodes of alkali-ion batteries in good agreement with experimental measurements, while avoiding empirical fitting is a highly desirable goal in materials science. In this work, we present the results of our calculations of the voltage profile of the α-NaMnO2cathode material, using the DFT+Umethod, parametrized computationally by the linear response approach. Our calculations reveal an improved agreement with the experimental voltage curve as compared to DFT+Ucalculations with a fitted and fixedUparameter, particularly for high voltages. Additionally, we also analyze how magnetic ordering of NaMnO2changes upon the process of deintercalation when Na charge carriers are removed, leading to the change of oxidation state of Mn cations of the bulk. We demonstrate that antiferromagnetic ordering, observed experimentally for NaMnO2and LiMnO2, indeed corresponds to lower energy with the change to ferromagnetic ordering upon removal of 40–50% of Na ions or more. Analysis of previously identified configurations of NaxMnO2(using experimental and theoretical methods) has also shown the importance of numerical evaluation of theUparameter for better agreement with experimental findings.