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

Lithium-ion batteries have transformed energy storage solutions with the layered materials LiNi_<i>x</i>Mn_<i>y</i>Co_<i>z</i>O₂ (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.