SEI Growth: Reaction-Diffusion Moving Boundary (2D)

This 2D companion to the SEI-growth simulator replaces the 3D version's assumed closed-form parabolic law with the real physics behind it: a coupled reaction-diffusion moving-boundary (Stefan) problem. Forty planar shells of electrolyte solvent diffuse toward the growing solid-electrolyte-interphase film by Fick's law, while a first-order interfacial reaction consumes solvent exactly at the moving boundary and deposits new SEI at the matching rate. Instead of plugging numbers into δ(t)=√(2·k·t), this model discovers whether growth looks linear or parabolic from the competition between reaction speed and diffusive resupply — the Damköhler number — and a live log-log regression on the actual simulated trajectory reports the emergent exponent back to you in real time. Temperature, cycling rate and an electrolyte-additive toggle all feed the real Arrhenius rate laws, exactly as in the 3D sim, but here you can watch the growth regime itself shift as you turn them.