Integrating Time-Domain and Frequency-Domain Analyses for Advanced Lithium-Ion Battery Characterization

Characterisation of internal electrochemical behaviour of a Lithium-ion battery (LIB) is crucial to assess performance, safety and lifespan. Combining different characterisation techniques complements the understanding and characterizes battery internal processes. In this study, the correlation between a time-domain characterization technique, galvanostatic intermittent titration technique (GITT), and a frequency domain, electrochemical impedance spectroscopy (EIS) technique for parameterization is studied. Both techniques provide insights into the kinetic and diffusion behaviour of LIB. However, both techniques characterize the battery considering different approaches. GITT measures overall polarization and diffusion coefficients using voltage transient response and relaxation time through RC components. Whereas EIS deconvolutes the internal behaviour of LIB into bulk resistance, charge transfer resistance and diffusion resistance. The experimental study reveals a strong correlation between ohmic resistance values derived from both techniques. Comparison studies between the two techniques provide insight into charge transfer and diffusion processes. This integrated approach advances LIB parameterization, aiding in the development of robust battery management systems and diagnostics for improved reliability and efficiency.