Joint-Domain Impedance Spectroscopy for Solid-State Batteries: Enabling Accelerated Characterization and Data-Driven Insights

Joint-domain (“hybrid”) impedance spectroscopy has the potential to accelerate characterization, improve understanding, and facilitate enhancement of solid-state batteries (SSB). By combining time- and frequency-domain data sets with the distribution of relaxation times (DRT), the hybrid approach generates accurate impedance measurements ≥ 10× faster than conventional methods. This substantially expands the conditions under which valid impedance spectra can be measured in SSB, enabling a variety of experiments from high-rate/low-frequency operando cycling to high-throughput multidimensional spectroscopy. A framework comprising hybrid spectroscopy, system-agnostic DRT visualizations, and data-driven modeling is a powerful tool for analyzing the complex electrochemical processes that are characteristic of SSB. This approach can pinpoint rate-limiting processes, identify sources of degradation, and reveal rate-dependent kinetics of battery processes. The hybrid technique has potential applications ranging from fundamental studies of new chemistries to industrial quality control, making it a valuable tool to incorporate into SSB workflows.