Sodium-Ion Voltage Profile & Differential Chart

This is a 2D chart-native counterpart to the 3D sodium-ion cell simulator: instead of watching Na⁺ ions shuttle through a rendered cell, you read the same two-electrode open-circuit-voltage model directly off three stacked plots — the cell's terminal-voltage curve, the two electrode potentials that combine to make it, and the numerical derivative that turns the hard carbon's near-zero-volt plateau into a sharp, unmistakable peak. C-rate, cycle-life fade and charge/discharge direction drive a live marker across all three curves in real time.