This article systematically dissects various charge/discharge curves of lithium-ion batteries. It explains the curve profiles corresponding to mainstream charging/discharging modes, including constant current (CC), constant voltage (CV), CC–CV, constant power, and constant resistance. It interprets the electrochemical mechanisms behind voltage plateaus, inflection points, and slope variations—such as polarization and phase transitions during lithium intercalation/deintercalation—and establishes a basic logic for curve interpretation. The article compares curve differences among cathode systems such as NCM (ternary) and LFP (lithium iron phosphate), analyzes the effects of C‑rate, temperature, and cycle aging on curve evolution, and demonstrates how to extract capacity, internal resistance, and coulombic efficiency from these curves. This provides a practical analytical approach for battery performance testing and materials research and development.
