Abstract:Electrochemical impedance spectroscopy (EIS), as a non-destructive testing method, is widely used to study the internal electrochemical processes of batteries. Dynamic impedance spectroscopy (DEIS) testing during charging and discharging is more capable of truly reflecting the health status of batteries. At present, DEIS detection mainly relies on electrochemical workstations. Due to the limitation of the excitation source power of the test instrument, it mostly stays in the detection and research of laboratory cells, and cannot be applied to the field detection of high-power module batteries yet. In this article, we propose a battery DEIS detection method without additional excitation, and design a static and dynamic EIS detection system applicable to battery cells and modules. Taking lithium iron phosphate batteries and standard RC resistor cells as testing objects, the proposed testing effects of traditional electrochemical workstations and the testing system are compared and analyzed. The results show that the proposed scheme not only has small testing error and good stability, but also has the significant advantage of not being limited by the power of the external excitation source, which has a good application prospect in the future evaluation of the operating state of large-scale energy storage batteries.