Abstract:

 In the process of lithium-ion power battery electrolyte injection, the electrolyte displacement efficiency directly affects the forming quality of the solid electrolyte interface (SEI) in the subsequent process. Microstructure of porous electrode in lithium-ion battery were reconstructed by four random growth parameter method, and an improved pseudo potential lattice Boltzmann model was used to simulate immiscible displacement in battery liquid injection process to investigate the effect of wall wettability and porosity of electrode structure in lithium-ion cell on the displacement efficiency. Research shows that the wetting property of porous electrode has a significant influence on the displacement efficiency. With the increase of contact angle, displacement efficiency decreases. In single porosity zone, with porosity increases, the displacement efficiency is enhanced and less material is left. However, when the electrolyte flows through the interface between the anode and separator, because of difference of wetting characteristics and porosity, the electrolyte shows different displacement efficiency. The higher porosity zone has seepage in the vertical direction of flow, which reduces the displacement efficiency in other side and formed bubbles to affect the formation of SEI.

Key words: lattice Bolztmann, pseudo potential model, battery injection, displacement efficiency