Visualization of Stochastic Nucleation and Confined Propagation in Graphite Lithiation

optical imaging with high spatiotemporal resolution, we directly visualized phase transitions in individual graphite microparticles under realistic conditions. We uncovered a previously unrecognized "stochastic nucleation and confined propagation" regime during the stage 1L-3L and 3L-2 transitions, marked by asynchronous domain evolution. Kinetic analysis further revealed distinct rate-limiting mechanisms: interfacial ion transport governs early transitions, whereas solid-state diffusion controls the final 2-1 transition. These insights establish a unified mechanistic framework for graphite phase transformations and offer guidance for designing materials and charging strategies to enable fast-charging lithium-ion batteries.