Lithium battery charging curve reconstruction method based on capacity increment analysis and charging segment

Abstract

The invention belongs to the technical field of charging curve reconstruction, and particularly relates to a lithium battery charging curve reconstruction method based on capacity increment analysis and a charging fragment, which comprises the following steps of: collecting charging data, performing polarization analysis based on a second-order RC equivalent circuit model, selecting the data after polarization stabilization as an effective input fragment, and calculating the charging curve of a lithium battery. Analyzing the charging curve by using a capacity increment analysis method; aligning a plurality of capacity increment curve segments along a voltage axis to construct an observation matrix, performing soft threshold contraction operation on a current estimation matrix based on a singular value threshold method, and continuously correcting a low-rank estimation matrix through an iterative optimization process; and in the correction process, calculating the relative variation of the Floribenius norm of the matrix subjected to continuous two iterations, and when the iteration stopping condition is met, outputting the currently corrected low-rank estimation matrix as a complemented reconstruction result. According to the method, the repeatable behavior characteristics of the battery in the constant-current charging process are fully utilized, so that data acquired in different periods have high comparability.

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