Method and device for simplifying and reconstructing temperature field of single-layer battery cell of lithium ion battery

The invention provides a simplified reconstruction method and device for a temperature field of a single-layer battery cell of a lithium ion battery, and the method comprises the steps: inputting a boundary condition and an initial condition into a mixed-phase heat transfer equation, and obtaining a reconstructed mixed-phase heat transfer equation; geometric parameters, thermal parameters and actually measured temperature data of the single-layer battery cell of the lithium ion battery are input into the polynomial approximate simplified model; the actually measured temperature data comprises temperature-time data and heat production power surface density-time data; reconstructing a temperature field of the single-layer battery cell through the polynomial approximation simplification model, and outputting temperature space-time distribution two-dimensional data of the single-layer battery cell; and analyzing the working condition of the single-layer battery cell based on the temperature space-time distributio