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arXiv physics/0611232physics.chem-ph
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大电压下电解质动力学中的空间效应:II。修正的泊松-能斯特-普朗克方程

Steric effects in the dynamics of electrolytes at large applied voltages: II. Modified Poisson-Nernst-Planck equations

Mustafa Sabri Kilic, Martin Z. Bazant, Armand Ajdari

摘要:

在涉及大电位或表面电荷的情况下,泊松玻尔兹曼(PB)方程有缺点,因为它忽略了离子-离子相互作用和空间效应。这已经被电化学界广泛认可,导致各种替代模型的发展,从而产生不同的“修改的PB方程”,其至少在预测平衡离子分布方面取得了定性的成功。另一方面,文献是稀缺的,在这些制度的浓度动态的描述。在这里,调整策略,修改PB方程,我们提出了一个简单的修改广泛使用的泊松-能斯特-普朗克(PNP)方程的离子传输,这至少定性占空间效应。我们分析这些MPNP方程的数值解的模型问题的充电的一个简单的电解质电池,并比较的结果,标准的PNP方程。最后,我们重复Bazant,Thornton和Ajdari(2004)对这个新方程组的渐近分析,以进一步证明第一部分中介绍的更简单的等效电路模型对此类问题的有效性的兴趣和限制。

英文摘要:

In situations involving large potentials or surface charges, the Poisson Boltzman(PB) equation has shortcomings because it neglects ion-ion interactions and steric effects. This has been widely recognized by the electrochemistry community, leading to the development of various alternative models resulting in different sets "modified PB equations", which have had at least qualitative success in predicting equilibrium ion distributions. On the other hand, the literature is scarce in terms of descriptions of concentration dynamics in these regimes. Here, adapting strategies developed to modify the PB equation, we propose a simple modification of the widely used Poisson-Nernst-Planck (PNP) equations for ionic transport, which at least qualitatively accounts for steric effects. We analyze numerical solutions of these MPNP equations on the model problem of the charging of a simple electrolyte cell, and compare the outcome to that of the standard PNP equations. Finally, we repeat the asymptotic analysis of Bazant, Thornton, and Ajdari(2004} for this new system of equations to further document the interest and limits of validity of the simpler equivalent electrical circuit models introduced in Part I for such problems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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