The application discloses a
lithium battery energy storage monitoring method and
system, which comprises the following steps: obtaining a historical
solid-
phase diffusion coefficient sequence and a historical liquid-phase impedance sequence, and establishing a
coupling correlation matrix therebetween; obtaining a real-time
solid-
phase diffusion coefficient and a real-time liquid-phase impedance through
online identification; selecting a first candidate period through sliding window
correlation analysis; selecting a second candidate period through
impedance spectrum shape similarity calculation; calculating a current
capacity loss amount by using a
nonlinear diffusion-impedance
coupling model; determining a current calibration capacity based on an initial calibration capacity and an
aging factor; and determining a remaining available capacity based on the current calibration capacity and the current
capacity loss amount. By extracting the
diffusion-impedance
coupling correlation matrix from historical data and deeply embedding the whole process of parameter identification, candidate period screening,
capacity loss calculation and remaining capacity evaluation, the accuracy and robustness of the
estimation of the remaining available capacity of the
lithium battery are significantly improved.