Impedance Spectra Associated with Metal Deposition at the Negative Electrode from Contaminating Metal Particles at the Positive Electrode in a Lithium Ion Battery

Lithium ion batteries have the issue of internal short-circuiting by the electrodeposition of metal at the negative electrode. This deposition follows the anodic dissolution of metal particle contaminants incorporated into the positive electrode in manufacturing process. Thus, we have investigated the dissolution-deposition behavior of metals such as copper, nickel, iron, and stainless steel so far. We also proposed diagnosis method for the incorporation of the metal particles by electrochemical impedance spectroscopy, taking advantage of characteristic changes of the impedance spectra (phase angle) between 10-1 Hz. In the present study, we provide further insights into the variation of the impedance spectra associated with the growth of the metal deposits at the negative electrode.