Transmission Line Circuit and Equation for an Electrolyte-Filled Pore of Finite Length

I discuss the strong link between transmission line (TL) equation and TL circuit model for charging of an electrolyte-filled pore finite length. In particular, show how Robin Neumann boundary conditions to equation, proposed by others on physical grounds, also emerge in subject a stepwise potential. The relaxes with timescale $\ensuremath{\tau}$, expression which consistently follows from circuit, pore's known impedance. An approximation $\ensuremath{\tau}$ explains numerically determined relaxation time stack-electrode Lian et al. [Phys. Rev. Lett. 124, 076001 (2020)].