An Overdischarge Fault Detection Method for Lithium-ion Battery Module Based on Vibration Characteristics

Lithium-ion battery (LIB) has been the primary energy storage system for electric vehicles (EVs) due to its outstanding performance in high energy density and long cycle life. But its fragile safety especially overdischarge fault is an intractable problem. By designing overdischarge experiment of LIB to obtain the characteristics of cell's vibration signal under normal and overdischarge conditions, the high frequency components of the vibration spectra are extracted when the LIB is overdischarged. The high frequency vibration signal can used as an indicator to detect the overdischarge fault. To validate the feasibility and reliability of the proposed scheme, vibration signal of the module consisting of 4 series connected LIBs with one cell overdischarged are further studied for practical application. The result shows that high frequency components of vibration signal can be detected on the surface of the module, which indicates that the proposed approach is effective and robust in detecting overdischarge fault.