Statistical Kinetics of Phase-Transforming Nanoparticles in LiFePO4 Porous Electrodes

TL;DR

This paper presents a mathematical model showing how statistical kinetics in phase-transforming nanoparticles within porous electrodes can produce complex transient currents, potentially misleading interpretations based on classical nucleation theories.

Contribution

The study introduces a simplified mathematical framework that separates nucleation and surface reaction effects, enabling better understanding of nanoparticle phase transformations in electrochemical systems.

Findings

Transient currents can be non-monotonic due to statistical effects.

Nucleation and surface reactions can be decoupled in the model.

Model helps interpret nanoparticle dynamics from electrode responses.

Abstract

Using a simple mathematical model, we demonstrate that statistical kinetics of phase-transforming nanoparticles in porous electrodes results in macroscopic non-monotonic transient currents, which could be misinterpreted as the nucleation and growth mechanism by the Kolmogorov-Johnson-Mehl-Avrami (KJMA) theory. Our model decouples the roles of nucleation and surface reaction in the electrochemically driven phase-transformation process by a special activation rate and the mean particle-filling speed of active nanoparticles, which can be extracted from the responses of porous electrodes to identify the dynamics in single composing nanoparticles.