Development of a numerical framework for the analysis of a multi-tone EIS measurement system

This paper describes an integrated co-simulation framework of circuital/behavioural/algorithmic type devoted to the design, simulation, and support to validation of a system of measurement based on electrochemical impedance spectroscopy (EIS) for lithium-ion battery cells. The simulation framework comprises two main parts: a circuital simulator and a numerical environment. It allows the study of a generic system: in particular, it has been applied to analyze an EIS system as a whole without neglecting the effects of the hardware nonidealities on the software algorithm (through a direct connection between the circuital simulator and the numerical environment). A model is implemented inside the circuital simulator, replicating as accurately as possible an existing laboratory prototype devoted to EIS measurements. After the simulation of the prototype, the numerical environment executes an algorithmic elaboration to estimate impedance values for a lithium-ion battery. Throughout several simulations, it is possible to check the non-idealities of the prototype. The simulation framework identified and corrected a malfunction of the prototype available in the laboratory and thus permitted the implementation of a circuit with improved performance.