self.D_eff is always None for electrode solver

[LDXu93]

self.D_eff is initialized for ElectrodeSolver at line 563, but is not updated in the rest of the solver.

I'm wondering if I can compute the effective diffusivity in this case, since the electrode tortuosity factor seems not request to update diffusivity iteratively.

[LDXu93]

I guess I can calculate D_eff by $\frac{\tau_e}{porosity} = \frac{1}{D_{eff}}$, right?