The real-time detection of lithium precipitation is significant to avoid internal short circuit and even thermal runaway. Distinguished from the sophisticated, long-duration testing in the lab, the paper introduces an innovative method for detecting lithium precipitation in the application scenarios of the battery charging process. First, the Warburg impedance is extended to conical symmetry and the lithium-ions diffusion model for lithium precipitation is presented. Second, to measure the parameters inside the battery at the microscopic scales by the external variable, porous electrode model for lithium precipitation is created. Third, lithium precipitation detection technique easily integrated in the charging device is presented. The result indicates that the ripple current is high when the SOH of the normal battery is up to 93.2%, but the ripple current goes down when the SOH is 27.4% due to lithium precipitation. Compared with the impedance of normal batteries around the cluster centre in the low-frequency range of 0.5~3 Hz, the battery impedance with lithium precipitation is Scattered and uncertain

Keywords: Lithium precipitation, Warburg, Lithium-ions diffusion model, Porous electrode model, Charging.