Conclusion
Low-cost impedance spectrometer for characterizing electrochemical devices

This article presented and demonstrated a method for implementing SIE at low cost (generally less than 3% of the cost of commercial equipment). By leveraging existing experimental equipment in the original system—or with minimal upgrades—a modular implementation, and a frequency analysis based on conventional methods such as the FFT, this approach enables accurate impedance measurements without relying on expensive commercial instruments. Experiments were conducted on a 2-kW electrolyzer, covering a frequency range from 0.03 Hz to 6 kHz. The root mean square errors (RMSE) for amplitude and phase, compared to measurements obtained with a commercial Zahner SIE device, are 3.8505 × 10 ⁻⁴ Ω·cm ² for amplitude and 0.0055 rad for phase, respectively. This experimental validation shows excellent agreement,...