From lithium to sodium: A comparative study of temperature and SOC dependence in second-order RC parameters for battery management migration

Directly applying Lithium-ion Battery (LIB) management logic to Sodium-ion Batteries (SIBs) compromises state estimation accuracy due to inherent electrochemical disparities. To bridge this gap, we systematically characterize and compare the temperature and State-of-Charge (SOC) dependencies of second-order RC model parameters across LFP, NCM, and SIB chemistries. We conducted extensive hybrid pulse power characterization spanning wide operating ranges to quantify parameter sensitivity, thermal entropy, and statistical variability. Our comparative analysis reveals that while SIBs offer superior state observability through quasi-linear Open-Circuit Voltage (OCV) profiles, they exhibit distinct kinetic challenges: specifically, an exacerbated sensitivity of Ohmic resistance to low temperatures and significant heterogeneity in polarization parameters. Addressing these specificities, we propose a “Migration-Oriented Parameter Grouping” framework that categorizes parameters for targeted optimization. Consequently, we advocate for a strategic transition from the conventional “Resistance-Centric” calibration to a “Temperature-Centric,” adaptive modeling paradigm. This work provides the theoretical basis and data support essential for developing high-precision BMS for next-generation sodium-based energy storage.