The Effect Of Separation Anode Coatings On Properties Of Lithium-Sulfur Battery

Lithium-sulfur battery has attracted tremendous attention from the energy storage community, mainly due to its high theoretical energy density, which is more than twice that of conventional Li-ion batteries; this makes it one of the most promising candidates to meet the energy needs. However, to use Li metal as an anode is a challenging task because the Li anode forms dendritic and mossy metal deposits, leading to low Coulombic efficiency and short cycle life, as well as safety concerns. Taking into account of these problems, the separator coatings facing lithium anode were designed and prepared creatively for improving the properties of lithium-sulfur battery in the research.1. The PVDF separator coating facing lithium anode was prepared successfully for improving the properties of lithium-sulfur battery. The results showed that when the thickness of coating layer was only 2.5/?m, the initial discharge specific capacity is 1173mAh/g and the reversible capacities after 8O cycles reach to 722mAh/g, which the average coulombic efficiency increases to 99% at the current of 2OOmA/g. It is demonstrated that PVDF coating is quite effective in reducing shuttle effect and protecting lithium anode corrosion.2. The LiNO3/Al2O3/PVDF separator coating was designed and prepared firstly to protect the lithium anode and improve the properties of lithium-sulfur battery by the dual role of Al2O3/PVDF and LiNO3 sustained release. At the current of 2OOmA/g, the initial discharge specific capacity is up to 1283mAh/g and the reversible capacities after 1OO cycles reach to 712mAh/g. Herein, the coating as a stable interlayer between separator and lithium anode has higher intial discharge capacity, better electrochemical performance and surface morphology of lithium anode than routine separator. Meanwhile, it suppresses the side reactions between soluble lithium polysulfides and lithium anode.3. The PDMS separator coating was explored for protecting lithium anode in the lithium-sulfur battery. At the current of 2OOmA/g, the initial discharge specific capacity is 1O43mAh/g and the reversible capacities after 1OO cycles reach to 818mAh/g, which the capacity retention is above 78%. It is demonstrated that PDMS coating is effective in reducing shuttle effect, inhibiting the growth of lithium dendrites and improving the cycle performance of lithium-sulfur battery. This result has not been reported.