Understanding non-linearity in electrochemical systems using multisine-based non-linear characterization

Background: With the development of advanced characterization techniques, lithium-ion battery non-linearities have recently gained increased attention which can benefit health diagnosis and ageing mechanism identification. In comparison to conventional single sine wave-based methods, multisine-based non-linear method has advantage capturing dynamic voltage response within a short testing duration, therefore further potential for on-board applications. However, understanding electrochemical processes that contribute is still unclear. Methods: this paper, sensitivity Doyle–Fuller–Newman model parameters are analysed in frequency domain investigate dynamics response. To begin with, with validated characterized compared experimental data from commercial cell. This demonstrated significant difference between mathematical determined experimentally. Then, global analysis applied determine most sensitive parameter contributing non-linearities. Finally, appropriate value results closest estimated through minimizing root mean square error. Results: The show charge transfer coefficient among parameters. good agreement results, when Butler–Volmer kinetic asymmetrical due unequal anodic cathodic coefficients.