New Approached for Determining the Degree of Dissociation of a Salt by Measurements of Dynamic Properties of Lithium Ion Electrolytes
New Approached for Determining the Degree of Dissociation of a Salt by Measurements of Dynamic Properties of Lithium Ion Electrolytes
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通过测量锂离子电解质的动态特性测定盐解离度的新方法
DOI：
10.1021/jp020703y
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发表时间：
2002
影响因子：
3.3
通讯作者：
Yuria Saito
中科院分区：
文献类型：
--
作者：
Hiroshi Kataoka and;Yuria Saito
提出了一种新的推导思路，即利用观测到的扩散系数和离子迁移率来推导电解质溶液中盐的离解度。动态值可以通过脉冲梯度自旋回波NMR技术测量单个物种。所观察到的扩散系数由解离离子和缔合离子对贡献。另一方面，观察到的迁移率仅反映离子的迁移行为。结合这些值，我们独立地推导出盐的解离度。将该模型应用于分散有10 - 15重量%的PVDF-HFP的EC/DEC（2/3，1 M）中的Li-TFSI的实际锂电解质溶液样品。使用NMR观察到的迁移率，盐的解离度的估计值为0.75 - 0.90。当我们将电导率用于该估计时，解离度在0.55至0.70的范围内。两个估计之间的绝对值的差异是由于t的差异。
A new derivation idea for the dissociation degree of the salt of an electrolyte solution using the observed diffusion coefficient and ionic mobility was proposed. The dynamic values could be measured for individual species by the pulsed gradient spin−echo NMR technique. The observed diffusion coefficient is contributed from the dissociated ion and the associated ion pair. The observed mobility, on the other hand, reflects the migration behavior of only the ion. Combining these values, we independently derived the dissociation degree of the salt. This model was applied to the actual lithium electrolyte solution samples of Li-TFSI in EC/DEC (2/3, 1 M) dispersed with 10−15 wt % of PVDF−HFP. The estimated value of the dissociation degree of the salt was 0.75−0.90 using the observed mobility by NMR. When we applied the electrical conductivity for this estimation, the dissociation degree was in the range of 0.55 to 0.70. The difference in the absolute values between two estimations is due to the difference in t...