论文标题
超级电容器堆栈电极模型的充电动力学的渐近分析
Asymptotic analysis on charging dynamics for stack-electrode model of supercapacitors
论文作者
论文摘要
超级电容器由于其在快速充电/放电速率，较长的周期寿命，稳定性等方面的出色性能而有希望的电化学能源存储设备。超级电容器充电时间尺度的实验测量和理论预测通常具有很大的差异。这项工作开发了一种匹配的渐近扩展方法，可以通过多孔电极得出超级电容器的充电动力学，其中堆栈电极模型描述了超级电极。通过离子浓度和通量连续的每两个堆栈之间的前阶溶液耦合前阶解会导致ode系统，这是ZETA电位的广义当量电路模型，具有潜在的依赖性的非线性电容和电阻，由电解质的物理参数确定，例如，特异性计数器（例如，特异性的反式价值），是非数值的。在开发投影后，对ODE系统的线性化稳定性分析是从理论上表征充电时间尺度的。衍生的渐近溶液已数值验证。对BiexPential充电时间尺度的进一步数值研究表明，所提出的广义等效电路模型以及伴侣线性化的稳定性分析可以忠实地捕获具有多孔电极的超级电容器中对称/非对称电解质的充电动力学。
Supercapacitors are promising electrochemical energy storage devices due to their prominent performance in rapid charging/discharging rates, long cycle life, stability, etc. Experimental measurement and theoretical prediction on charging timescale for supercapacitors often have large difference. This work develops a matched asymptotic expansion method to derive the charging dynamics of supercapacitors with porous electrodes, in which the supercapacitors are described by the stack-electrode model. Coupling leading-order solutions between every two stacks by continuity of ionic concentration and fluxes leads to an ODE system, which is a generalized equivalent circuit model for zeta potentials, with the potential-dependent nonlinear capacitance and resistance determined by physical parameters of electrolytes, e.g., specific counterion valences for asymmetric electrolytes. Linearized stability analysis on the ODE system after projection is developed to theoretically characterize the charging timescale. The derived asymptotic solutions are numerically verified. Further numerical investigations on the biexponential charging timescales demonstrate that the proposed generalized equivalent circuit model, as well as companion linearized stability analysis, can faithfully capture the charging dynamics of symmetric/asymmetric electrolytes in supercapacitors with porous electrodes.
