Interparticle Communication and Lithium Dynamics in Faceted Nickel-Rich NMC Cathodes.

Lithium-ion batteries have transformed energy storage solutions with the layered materials LiNixMnyCozO2 (NMC) at the forefront of commercial cathodes due to their superior performance. However, understanding the complex dynamics of lithium-ion diffusion within these materials remains a challenge, as conventional models used to analyze experimental results often simplify particle size distributions, intercalation kinetics and mechanisms, often ignoring interactions between particles. This study explores the anisotropic lithium-ion transport in NMC cathodes with octahedral particle morphologies. Using charge photometry (CP) under charge-rest protocols, the research unveils distinct transport behaviors across different facets of the particle. These findings, corroborated through finite element simulations, highlight the critical role of interparticle communication─an interaction previously underappreciated but shown here to be significant. By combining experimental evidence with computational modeling, this study provides a deeper comprehension of lithium-ion transport and the underlying mechanisms, offering valuable insights to future studies of active materials for battery applications.