Communication: Elucidating Individual Impedance Contributions via a Versatile Reference Electrode for Lithium-Ion Batteries

The integration of a versatile reference electrode into multi-layered pouch cells enables impedance deconvolution in lithium-ion batteries. This reference electrode facilitates isolation of impedance contributions from the cathode, anode, and full cell across a range of states of charge. The reference electrode design minimizes artefacts commonly associated with three-electrode configurations, allowing for clean impedance measurements. Fourier transform techniques were applied to reconstruct HPPC voltage responses, confirming consistency between frequency-domain and time-domain characterizations. These findings demonstrate that 3-electrode EIS with this versatile reference electrode captures transient voltage behavior at various timescales, supporting diagnostics, model calibration, and battery health monitoring.