International Journal of Energy Research, Vol.45, No.5, 7732-7740, 2021
A practical approach to predict volume deformation of lithium-ion batteries from crystal structure changes of electrode materials
Volume deformation of lithium-ion batteries is inevitable during operation, affecting battery cycle life, and even safety performance. Accurate prediction of volume deformation of lithium-ion batteries is critical for cell development and battery pack design. In this paper, a practical approach is proposed to predict the volume deformation of lithium-ion batteries. In the proposed method, the deformation of a full cell is determined as the superposition of the thickness changes of cathodes and anodes, which are induced by the expansion/contraction of crystal structure during lithiation/de-lithiation. The electrodes' crystal volume changes are calculated based on the evolution of lithium stoichiometry in cathode and anode, which can be identified through the reconstruction of the battery charging voltage profile. Finally, the thickness changes of cathode and anode as well as the deformation of the full cell are predicted. The proposed method can achieve accurate predictions of the deformations of lithium-ion batteries with various chemistries, with the predicted errors less than 10%. Moreover, the proposed method can help to interpret the differences in deformation profiles of batteries with different chemistries, and provide useful guidance for cell development.