Method, system and storage medium for solid-phase concentration correction of lithium batteries

A method for solid phase concentration correction of a lithium battery, comprising:

• establishing an electrochemical model of the lithium battery;
• initializing a solid phase concentration in the electrochemical model to be a first solid phase concentration;
• simulating a simulated output voltage of the lithium battery in a preset period of time according to the electrochemical model, a preset current and the first solid-phase concentration;
• acquiring an actual output voltage of the lithium battery in the preset period of time;
• calculating an error coefficient between the simulation output voltage and the actual output voltage, and presetting an error threshold corresponding to the error coefficient, wherein the error coefficient comprises a voltage difference and a voltage mean square error of an initial detection value;
• and
• when the error coefficient is greater than the error threshold, performing an iterative correction on the first solid phase concentration until the error coefficient is not greater than the error threshold, and outputting the corrected first solid phase concentration as a second solid phase concentration, wherein the iterative correction of the first solid phase concentration comprises:
• iteratively correcting a positive electrode solid phase concentration in the first solid phase concentration using a gradient descent method, according to a formula of:
• c
• =
• c
• -
• lr
• ×
• Δ
• ⁢
• V
• ×
• dc
• docp
• wherein c is the positive electrode solid phase concentration in the first solid phase concentration, lr is the correction coefficient, ΔV is the voltage difference, ocp is an open circuit potential of the electrode when the solid phase concentration of the positive electrode is c;
• and
• correcting a negative electrode solid-phase concentration in the first solid-phase concentration according to the corrected positive electrode solid-phase concentration, according to a formula of:
• c
• n
• ,
• 100
• -
• c
• n
• ,
• soc
• c
• p
• ,
• soc
• -
• c
• p
• ,
• 100
• =
• L
• p
• ⁢
• ε
• p
• L
• n
• ⁢
• ε
• n
• ;
• wherein cn,100 is a concentration of a negative electrode active material of the lithium battery at soc=100%, cn,soc is a concentration of the negative electrode active material of the lithium battery at soc, Ln is a thickness of the negative electrode active material, εn is a volume fraction of the negative electrode active material, and p represents a positive electrode active material of the lithium battery.