论文标题
离子插入纳米膜中的多相极化：一般理论，包括各种表面效应和记忆应用
Multiphase polarization in ion-intercalation nanofilms: general theory including various surface effects and memory applications
论文作者
论文摘要
离子浓度极化（CP，电流诱导的浓度梯度与电荷选择性界面相邻）已经很好地研究了单相混合导体（例如，液体电解质），但是在文献中很少解决多相CP。在我们最近的出版物中，我们提出，高于某些阈值电流的CP可以翻转由离子阻断电极夹杂的多相离子间呈纳米膜中的相位分布。我们将此现象称为多相极化（MP）。然后，我们提出，MP可以进一步导致具有离子调节的电子转移的非对称电极的非挥发性界面电阻开关（RS），理论可以再现LTO Memristors的实验结果。在这项工作中，我们得出了一个综合的2D相位模型，用于在离子交流材料中耦合离子 - 电子传输，其表面效应包括电子传递动力学，非中性润湿，能量弛豫和表面电荷。然后，我们使用该模型来研究MP。我们提出相位边界的时间演变，并分析各种边界条件的切换时间，电流，能量和环状伏安法。我们发现，通过操纵表面条件和平均浓度可以显着提高开关性能。最后，我们讨论了基于MP的记忆的前景以及当前模型的可能扩展。
Ion concentration polarization (CP, current-induced concentration gradient adjacent to a charge-selective interface) has been well studied for single-phase mixed conductors (e.g., liquid electrolyte), but multiphase CP has been rarely addressed in literature. In our recent publication, we proposed that CP above certain threshold currents can flip the phase distribution in multiphase ion-intercalation nanofilms sandwiched by ion-blocking electrodes. We call this phenomenon as multiphase polarization (MP). We then proposed that MP can further lead to nonvolatile interfacial resistive switching (RS) for asymmetric electrodes with ion-modulated electron transfer, which theory can reproduce the experimental results of LTO memristors. In this work, we derive a comprehensive 2D phase-field model for coupled ion-electron transport in ion-intercalation materials, with surface effects including electron transfer kinetics, non-neutral wetting, energy relaxation, and surface charge. Then we use the model to study MP. We present time evolution of phase boundaries, and analyze the switching time, current, energy, and cyclic voltammetry, for various boundary conditions. We find that the switching performance can be improved significantly by manipulating surface conditions and mean concentration. Finally, we discuss the prospects of MP-based memories and possible extensions of the current model.
