Investigation On The Electrical And Mechanical Property For The Several Kind Of Lithium-Ion Battery Electrode Structure

Lithium-ion battery is a kind of rechargeable battery which can be repeatedly used. The lithium-ion battery works with an insertion/move/extraction process. During this process, the coupling effects of the electrode structure’s mechanical deformation and lithium-ion diffusion behavior appear. The coupling effects are closely related to the electrode materials and structural characteristics, which determine the capacity of lithium-ion battery, service life and other important indicators. This paper revolves around electrical and mechanical properties of several electrode structures, and establishes a coupling theoretical model of the electrode structure continuum mechanics deformation and lithium-ion diffusion. We make a quantitative analysis of the model established by using finite element simulation, and obtain several innovative research results as follows.We establish an elastic-diffuse coupling model specifically to the square column lithium-ion battery under constant current charging condition. Based on the model stated above, a quantitative simulation with respect to the square column electrode structure is presented in this paper through the commercial FEA software. According to the results, we verify the surface locking phenomenon. We find that the larger diffusion coefficient without the effect of diffusion and the smaller elasticity modulus, poisson ratio, partial molar volume of the solute are in favor of the diffusion, which also put off the surface locking phenomenon.Besides, we establish a hollow square column lithium-ion battery model. By changing the size of the hole, we find that the maximum compressive stress in the electrode achieves a minimum value when the side length of the hole is a special value; meanwhile the time of the surface locking phenomenon happen is moderation. This special size may become the best project of the hollow square column lithium-ion battery. Based on this hollow structure, we also discuss several kinds of charging mode, and get a prioritization scheme. In addition, we consider a layered structure with a smaller elasticity modulus material on its surface and find that the maximum compressive stress in the electrode become smaller as the thickness of the surface layer get larger, and the surface locking phenomenon can be significantly delayed.