Cyclosulfate additive constructs stable interface to limit dendrites and realize stable cycle of LMBs

Due to the high reactivity of Li metal, Li dendrites inevitably grow during the charging and discharging process of the cell, resulting in poor cycling performance. In this paper, 1,3 -propane sulfonate (PS) was innovatively used as a functional additive, and a stable sulfur-rich SEI layer was constructed on the surface of the Li metal anode through the synergistic deposition of its decomposition product and electrolytes. This SEI layer effectively inhibited the uncontrollable growth of Li dendrites and significantly enhanced the cycling performance of Li/ LiNi0.8Co0.1Mn0.1O2 cells, enabling the cells to achieve 200 stable cycles at 0.5C and 400 stable cycles at 5C. The morphology and composition on the surface of the Li metal anode were observed and analyzed through SEM and XPS, confirming the mechanism of PS. It was confirmed by cyclic voltammetry and GITT that the modified SEI layer resulted in better Li+ conductivity and exhibited lower impedance values. In addition, in-situ optical microscopy was innovatively used to observe the changes in the growth of Li dendrites, demonstrating that PS effectively inhibited the growth of uncontrolled Li dendrites on the surface of the Li metal anode.