Analysis of the Separator Thickness and Porosity on the Performance of Lithium-Ion Batteries

Abstract

In this paper, investigation on the effect of separator thickness and porosity on the performance of Lithium Iron Phosphate batteries are analyzed. In recent years there have been intensive efforts to improve the performance of the lithium-ion batteries. Separators are important component of lithium-ion batteries since they isolate the electrodes and prevent electrical short-circuits. Separators are also used as an electrolyte reservoir which is used as a medium for ions transfer during charge and discharge. Electrochemical performance of the batteries is highly dependent on the material, structure, and separators used. This paper compares the effects of material properties and the porosity of the separator on the performance of lithium-ion batteries. Four different separators, polypropylene (PP) monolayer and polypropylene/polyethylene/polypropylene (PP/PE/PP) trilayer, with the thickness of 20 μm and 25 μm and porosities of 41%, 45%, 48%, and 50% were used for testing. It was found that PP separator with porosity of 41% and PP/PE/PP separator of 45% porosity perform better compared to other separators.