Controlling the SEI of Li metal anode by reactive sulfur containing polymer layer

Abstract

Recently, as the demand for secondary batteries with high energy density has increased, studies on lithium metal anode have been actively carried out due to its high theoretical capacity (3864mAh/g) and the lowest redox potential (-3.04V vs SHE). However, low coulombic efficiency due to the high reactivity of the lithium metal anode and safety issues due to the short circuit originated from dendrite generation. These problems are main obstacles for commercialization of the battery using the lithium metal anode. Here, this study introduces the sulfur containing polymer layer (PALA-S_70) to the surface of lithium and it decomposed to make homogeneous inorganic sulfide SEI to minimize the electrolyte decomposition and suppress the growth of dendrite. Therefore, stable operations over 400 cycles of Li symmetric cell is possible even under the high current density (3mA/$cm^2$) and the high areal capacity (3mAh/$cm_2$).