Microstructure evolution and mechanical analysis of lithium battery electrode in calendering deformation zone

The microstructure of the electrode and its mechanical properties are important factors affecting the performance of lithium batteries. Calendering is one of the most important aspects that affect the microstructure and mechanical response of lithium battery electrodes. Discrete element method was employed to establish a lithium battery electrode model that considered the real particle shape and size distribution. Subsequently, calendering simulations were conducted to reveal the microstructure evolution and mechanical properties of the electrode in the deformation zone. The results show that the electrode density and porosity in the calendering deformation zone change sharply at first and then slow down, and the appropriate increase of the roller diameter is helpful to alleviate this phenomenon. Calendering will cause the pore sizes in the electrode to become smaller, and this process reduces the floating range of the pore sizes. The stress change of the electrode during the calendering process mainly occurs in the normal direction (z-direction), but there is also a small stress change in the length direction (x-direction).