Equivalent sampling-enabled module-level battery impedance measurement for in-situ lithium plating diagnostic

Electrochemical impedance spectroscopy (EIS) is a promising technique for the diagnostic of lithium-ion battery (LIB). However, its onboard application is still challenging considering the limitation of in-vehicle environment. Motivated by this, this paper proposes an equivalent sampling-enabled module-level battery impedance measurement method, which shows a strong fidelity for lithium plating diagnostic. A module-level perturbation topology is designed allowing for the generation of high-precision perturbation current with reasonable space occupation. A simplified equivalent sampling method is exploited for the first time with the proposed topology, enabling the EIS sampling with low hardware cost and full compatibility with the commercially-ready battery monitoring chips. With the proposed prototype, an EIS feature-based nondestructive method is further proposed for the in-situ lithium plating diagnostic of LIB. Experimental results suggest that the proposed prototype can promise accurate EIS measurement within a broad frequency range from 0.1 Hz to 1160 Hz. Moreover, the capacity calibration and post-mortem tests validate the accuracy of the proposed EIS feature-based lithium plating diagnostic method.