Effect of MnO/PP separator on morphologies of Li metal deposition

The application of lithium metal anodes is hindered by low Coulombic efficiency (CE), serious lithium dendrites and volume expansion. An MnO/Polypropylene (PP) composite separator was developed to regulate lithium metal deposition behaviors through <italic>in situ</italic> forming stable artificial solid electrolyte interface (SEI) passivating layers. The concentration of MnO in the cells can be maintained at a constant based on quite low solubility of MnO in the liquid electrolyte, and the dissolved MnO can be reduced to produce Li₂O and Mn metal nanoparticles, which can not only function as nucleating seeds of lithium metal deposits but also repair the broken SEI layer. Dendritic-free Li deposits can be obtained by simple separator coating. It can also improve the electrochemical performance of lithium metal batteries. And it is benefit for applications of Li metal anodes.