Strain effects on Li+ diffusion in solid electrolyte interphases: A molecular dynamics study

Dilithium ethylene dicarbonate (Li 2 EDC) and dilithium butylene dicarbonate (Li 2 BDC) are the common organic compositions of the solid electrolyte interphase (SEI) layers in rechargeable lithium-ion batteries. The Li + diffusion in the amorphous and ordered phases of Li 2 EDC and Li 2 BDC under various strains has been investigated by using molecular dynamics simulations. It is found that different strains lead to diverse changes in Li + diffusivity. The tensile strain makes the Li + diffusion coefficients increase in amorphous and ordered Li 2 EDC or Li 2 BDC, and the compressive strain makes the Li + diffusion coefficients decrease in them. The average Li + coordination number calculation, ion conductivity calculation and the calculation of the residence autocorrelation function in amorphous and ordered Li 2 EDC or Li 2 BDC are performed to further analyze the strain effects on Li + transport in them. The factors influencing Li + diffusion in amorphous and ordered Li 2 EDC or Li 2 BDC under the strain are discussed.