Thin Plate Spline-Based Coulombic Efficiency Prediction of Lithium Battery

The performance of lithium-ion rechargeable battery depends on its coulombic efficiency, which determines the measurement accuracy of the state of charge as well. In this context, the regularity that coulombic efficiency changes with environmental temperature and charge-discharge rate was analyzed in different cases, and a TPS (Thin Plate Spline) surface fitting-based coulombic efficiency estimation method was proposed for lithium-ion rechargeable battery. The presented method has a unique advantage in 3D smooth surface interpolation, which made it possible to model the functional relationship between battery coulombic efficiency, ambient temperature and charge-discharge rate, and then adjust the reconstructed precision with the plate rigidity sequentially. The experimental results illustrate that the proposed method is able to estimate the corresponding coulombic efficiency in the presumed range of ambient temperature and charge-discharge rate without battery cycling procedure. Furthermore, the accuracy and promptness of the novel method are verified simultaneously.