Hierarchical framework for slurry impedance analysis of lithium-ion battery cathodes using a coin cell platform

Understanding the internal microstructure of lithium-ion battery slurries is essential for achieving high-performance electrodes. However, conventional rheological metrics such as viscosity and modulus offer only indirect insight into the electrically active network formed by conductive agents. Here, we present a standardized coin cell-based impedance spectroscopy framework that directly quantifies the internal structure of lithium-ion battery slurries. By applying the distribution of relaxation times analysis, we resolve distinct dielectric responses attributed to interfacial polarization and electrical conduction, and propose a unified equivalent circuit model. The extracted resistance and capacitance exhibit strong correlations with electrode-level electrical conductivity, microstructural tortuosity, and cell-level electrochemical performance metrics including initial capacity and rate capability. This scalable and reproducible approach enables predictive evaluation of slurry quality using only a coin cell and potentiostat, offering a practical tool for process monitoring and optimization in both lithium-ion and emerging battery systems. • Standardized coin cell enables reproducible slurry impedance analysis. • DRT analysis deconvolutes interfacial polarizations regarding homogeneity. • RC parameters of slurries correlate with electrode parameters and cell performance.