I am looking at the higher harmonic responses of large amplitude input perturbation current signal to a lithium ion battery. From the electrochemical standpoint I see certain characteristic features physically in the cell and a corresponding fingerprint in the harmonics. For example - the third harmonic is greater than the second harmonic in a specific frequency range whenever there is lithium plating in the battery cell. I want to understand what this means in terms of the second and third harmonic ? Any pointers to resources on this would be very helpful. Thank you in advance. Fell free to let me know if you need more information.