Electrochemical Characterization and DRT-Guided ECM Modeling of Commercial Sodium-Ion 18650 Cells
Year: 2026
Type: article
Abstract: Sodium-ion batteries are attracting increasing interest for stationary energy storage, yet their aging behavior and modeling remain less mature than for lithium-ion systems. This paper presents an initial experimental and modeling study of commercial 18650 sodium-ion cells (0.9 Ah) based on capacity measurements, incremental capacity analysis (ICA), differential voltage analysis (DVA), electrochemical impedance spectroscopy (EIS), and distribution of relaxation times (DRT). Cycling tests were performed under selected operating conditions, and the early aging response was monitored through repeated electrochemical characterization. The impedance spectra were interpreted using a DRT-guided equivalent circuit model (ECM), which was then used to reconstruct the cell voltage in the time domain under a representative current profile. The results show good alignment between measured and simulated voltage under moderate dynamic conditions, while also highlighting the limitations of the model under sharp current transients. In addition, the study reveals inter-cell variability and temperature-dependent degradation trends that deserve further statistical and mechanistic investigation. Overall, this work establishes a physically constrained modeling framework that links frequency-domain diagnostics to time-domain behavioral modeling and provides a basis for future state-of health prediction studies on commercial sodium-ion cells.
Authors: Corentin Piat, Ali Sari, Christophe Viton
Language: English
Subfield: Automotive Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,075
OpenAlex ID: W7163655680