...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, C. Nanomaterials and interfaces >Novel Na+ Ion Diffusion Mechanism in Mixed Organic-Inorganic Ionic Liquid Electrolyte Leading to High Na+ Transference Number and Stable, High Rate Electrochemical Cycling of Sodium Cells
【24h】

Novel Na+ Ion Diffusion Mechanism in Mixed Organic-Inorganic Ionic Liquid Electrolyte Leading to High Na+ Transference Number and Stable, High Rate Electrochemical Cycling of Sodium Cells

机译：Na +离子在有机-无机离子液体混合电解质中的扩散机理，导致高Na +转移数和稳定，高速率的钠电池电化学循环

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

Ambient temperature sodium batteries hold the promise of a new generation of high energy density, low-cost energy storage technologies. Particularly challenging in sodium electrochemistry is achieving high stability at high charge/discharge rates. We report here mixtures of inorganic/organic cation fluorosulfonamide (FSI) ionic liquids that exhibit unexpectedly high Na+ transference numbers due to a structural diffusion mechanism not previously observed in this type of electrolyte. The electrolyte can therefore support high current density cycling of sodium. We investigate the effect of NaFSI salt concentration in methylpropylpyrrolidinium (C(3)mpyr) FSI ionic liquid (IL) on the reversible plating and dissolution of sodium metal, both on a copper electrode and in a symmetric Na/Na metal cell. NaFSI is highly soluble in the IL allowing the preparation of mixtures that contain very high Na contents, greater than 3.2 mol/kg (50 mol %) at room temperature. Despite the fact that overall ion diffusivity decreases substantially with increasing alkali salt concentration, we have found that these high Na+ content electrolytes can support higher current densities (1 mA/cm(2)) and greater stability upon continued cycling. EIS measurements indicate that the interfacial impedance is decreased in the high concentration systems, which provides for a particularly low-resistance solid-electrolyte interphase (SEI), resulting in faster charge transfer at the interface. Na+ transference numbers determined by the Bruce Vincent method increased substantially with increasing NaFSI content, approaching >0.3 at the saturation concentration limit which may explain the improved performance. NMR spectroscopy, PFG diffusion measurements, and molecular dynamics simulations reveal a changeover to a facile structural diffusion mechanism for sodium ion transport at high concentrations in these electrolytes.
机译：环境温度钠电池有望成为新一代高能量密度，低成本储能技术。在钠电化学中特别具有挑战性的是在高充电/放电速率下实现高稳定性。我们在这里报告了无机/有机阳离子氟磺酰胺（FSI）离子液体的混合物，这些离子液体由于先前在这种类型的电解质中未观察到的结构扩散机理而显示出意想不到的高Na +转移数。因此，电解质可以支持钠的高电流密度循环。我们调查铜丙基电极和对称Na / Na金属电池中的甲基丙基吡咯烷鎓（C（3）mpyr）FSI离子液体（IL）中NaFSI盐浓度对可逆镀覆和钠金属溶解的影响。 NaFSI在IL中高度可溶，因此可以制备含有非常高的Na含量的混合物，其中Na含量在室温下大于3.2 mol / kg（50 mol％）。尽管整个离子扩散系数随碱金属盐浓度的增加而大大降低，但我们发现这些高Na +含量的电解质可以支持更高的电流密度（1 mA / cm（2））和更高的稳定性（持续循环）。 EIS测量表明，在高浓度系统中界面阻抗降低，这提供了特别低电阻的固体电解质界面（SEI），从而导致界面处电荷转移更快。通过Bruce Vincent方法确定的Na +迁移数随NaFSI含量的增加而显着增加，在饱和浓度极限处接近> 0.3，这可以解释性能的改善。 NMR光谱学，PFG扩散测量和分子动力学模拟揭示了在钠离子在这些电解质中的高浓度迁移时，结构转换机制的转变。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
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