Enhancing the Electrochemical Performance of NaCrO2 through Structural Defect Control
Enhancing the Electrochemical Performance of NaCrO2 through Structural Defect Control
复制标题
通过结构缺陷控制增强 NaCrO2 的电化学性能
DOI：
10.1021/acsaem.0c01302
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发表时间：
2020
影响因子：
6.4
通讯作者：
Shaw, L.
中科院分区：
文献类型：
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作者：
Luo, M.;Ortiz, A. L.;Shaw, L.
这项研究首次阐明，与Na-O键长和NaO_2层间距相比，在决定O_3-NaCrO_2阴极的比容量和容量保持率方面，Na~+在Na~+位的错位起着更重要的作用。结果表明，Cr3+离子在Na位错位程度较低、Na-O键长较长的O_3-NaCrO_2晶体具有较高的比容量、较好的容量保持率和较小的电池阻抗。此外，在Na面阳离子混合程度较高的O_3-NaCrO_2晶体在NaCrO_2和Na0.5CrO_2公式之间的300次充放电循环中形成了一些单斜O‘_3-NaCrO_2晶体，而在Na面阳离子混合程度较低的O_3-NaCrO_2晶体的菱面体结构是完全可逆的。本研究中发现的结构缺陷的影响是基于铬离子对钠平面上钠输运的干扰以及在循环过程中铬离子逐渐向钠平面迁移来解释的。本文的研究成果将为今后合理设计和合成高比容量、长期循环稳定的NaCrO2正极材料提供指导。
This study clarifies, for the first time, that misplacement of Cr3+ions at the Na+site plays a more important role in dictating the specific capacity and capacity retention over cycles of O3-NaCrO2cathodes than the Na–O bond length and the NaO2interlayer spacing do. It is shown that O3-NaCrO2crystals with a lower degree of misplacement of Cr3+ions at Na sites and a longer Na–O bond length have higher specific capacity, better capacity retention, and smaller cell impedance. Furthermore, O3-NaCrO2crystals with a high degree of cation mixing at the Na plane exhibit the formation of some monoclinic O′3-NaCrO2crystals over 300 charge/discharge cycles between NaCrO2and Na0.5CrO2formulas, whereas the rhombohedral structure of O3-NaCrO2crystals with a low degree of cation mixing at the Na plane is fully reversible. The effects of structural defects discovered in this study are interpreted based on the interference of Cr ions in Na transport on the Na plane and gradual migration of Cr ions to the Na plane during cycles. The insights established in this study will provide guidance in rational design and synthesis of NaCrO2cathode materials with high specific capacity and long-term cycle stability in the future.
影响因子：
3.4
作者：
Mei Luo;A. L. Ortiz;F. Guo;Z. Shi;Ling Li;Yang Ren;Xiaoyi Zhang;Zonghai Chen;L. Shaw
通讯作者：
Mei Luo;A. L. Ortiz;F. Guo;Z. Shi;Ling Li;Yang Ren;Xiaoyi Zhang;Zonghai Chen;L. Shaw
介绍电化学阻抗谱作为锂离子电池润湿度测量方法
DOI：
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发表时间：
2018
期刊：
影响因子：
--
作者：
Florian J. Günter;J. B. Habedank;David Schreiner;T. Neuwirth;R. Gilles;G. Reinhart
通讯作者：
G. Reinhart