State-of-Charge Monitoring and Battery Diagnosis of Different Lithium Ion Chemistries Using Impedance Spectroscopy

For lithium iron phosphate batteries (LFP) in aerospace applications, impedance spectroscopy is applicable the flat region of voltage-charge curve. The frequency-dependent pseudocapacitance at 0.15 Hz presented as useful state-of-charge (SOC) and state-of-health (SOH) indicator. same battery type, prediction error better than 1% for a quadratic calibration curve, less 36% linear model. An approximately correlation between Ah capacity observed long overcharge deep discharge are avoided. We verify method comparison to classical constant-current measurements. In case five examined lithium-ion chemistries, trend SOC lost if slope voltage curve versus changes. With nickel manganese cobalt (NMC), high modulus correlates with above 70%.