Cyclosulfate additive inhibits Li dendrite disorder growth to achieve stable cycles of Li metal battery

The high reactivity of lithium metal leads to the uncontrolled growth of lithium dendrites during the charging and discharging process of lithium metal batteries, which results in the poor cycle performance of batteries. In this paper, we innovatively utilized 1, 3-propanediol cyclic sulfate (PCS) as an additive to successfully construct a smooth and dense SEI layer containing sulfur element on the lithium metal anode surface. Under the action of PCS, the cells show excellent performance. After 200 cycles, cells with baseline electrolyte (BE) + 1 wt.% PCS still has a high capacity of of 148mAh g−1 and 81.38% capacity retention compared with cells with BE. In-situ optical microscopy is pioneeringly applied to showcase the generation and growth of lithium dendrites which showed that PCS participated in the formation of the SEI layer, indicating that this optimized SEI layer has better conductivity of Li+ and chemical stability, thus inhibiting malignant lithium deposition and electrolyte decomposition above the lithium metal anode.