...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Dalton transactions: An international journal of inorganic chemistry >Electronic density distribution of Mn-N bonds by a tuning effect through partial replacement of Mn by Co or Ni in a sodium-rich hexacyanoferrate and its influence on the stability as a cathode for Na-ion batteries
【24h】

Electronic density distribution of Mn-N bonds by a tuning effect through partial replacement of Mn by Co or Ni in a sodium-rich hexacyanoferrate and its influence on the stability as a cathode for Na-ion batteries

机译：通过在富含钠的六氰基甲甲酸钠中通过CO或Ni部分替代Mn的调节效果的电子密度分布及其对Na离子电池的阴极稳定性的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This study evaluates the effect of equimolar substitution of manganese by cobalt or nickel in hexacyanoferrate (HCF) open frameworks as electrode materials for Na-ion batteries. As the stability of Mn-N bonds is crucial to obtain long term stability and cyclability of manganese (Mn-HCF), the samples were analyzed thoroughly using several spectroscopic and structural methods. The XPS and infrared experiments reveal that the charge density around Fe is modulated by the presence of Co or Ni, which is associated with their high polarizing power, leading to decreased cell distortion as revealed by XRD. The Rietveld refinement demonstrated that the octahedra built by 3d metals and the cyanide nitrogen were distorted with the axial bond distances being larger than the equatorial distances. This octahedral distortion promotes the spin behavior of 3/2 for Mn2+ confirmed by magnetic experiments; the arising of this spin state is attributed to d orbital splitting determined by UV-Vis experiments. Therefore, the changes upon Mn substitution are related to the modification of the covalent character of Mn-N bonds, modulated by the effect of the Ni and Co polarizing power. All these properties improve the electrochemical stability of the Ni or Co substituted materials as Na-ion batteries, leading to higher capacity retention even at higher C-rates (5C) and good capacity recovery, in comparison with those obtained for Mn-HCF.
机译：该研究评估了六氰基甲醛（HCF）开放框架中钴或镍作为Na离子电池的电极材料的钴或镍等摩尔或镍的效果。随着Mn-N键的稳定性至关重要，对于获得锰（Mn-HCF）的长期稳定性和可环性至关重要，可以使用几种光谱和结构方法彻底分析样品。 XPS和红外实验表明，通过CO或Ni的存在调节Fe的电荷密度，其与它们的高偏振功率相关，导致XRD透露的细胞变形降低。 RIETVELD细化表明，通过3D金属和氰化物构建的八面体扭曲，轴向束距远距大于赤道距离。这种八面体畸变促进由磁实验证实的MN2 +的3/2的旋转行为;这种旋转状态的产生归因于UV-VIS实验确定的D轨道分裂。因此，Mn替代的变化与Mn-N键的共价特征的修饰有关，通过Ni和Co偏振功率的效果调节。所有这些性质改善了Ni或Co取代材料作为Na离子电池的电化学稳定性，与Mn-HCF获得的那些相比，即使在较高的C-Rates（5C）和良好的容量恢复，也能够升高容量保持。

著录项

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号