Coatings on Lithium Battery Separators: A Strategy to Inhibit Lithium Dendrites Growth

Lithium metal is considered a promising anode material for lithium secondary batteries by virtue of its ultra-high theoretical specific capacity, low redox potential, and low density, while the application of lithium is still challenging due to its high activity. Lithium metal easily reacts with the electrolyte during the cycling process, resulting in the continuous rupture and reconstruction of the formed SEI layer, which reduces the cycling reversibility. On the other hand, repeated lithium plating/stripping processes can lead to uncontrolled growth of lithium dendrites and a series of safety issues caused by short-circuiting of the battery. Currently, modification of the battery separator layer is a good strategy to inhibit lithium dendrite growth, which can improve the Coulombic efficiency in the cycle. This paper reviews the preparation, behavior, and mechanism of the modified coatings using metals, metal oxides, nitrides, and other materials on the separator to inhibit the formation of lithium dendrites and achieve better stable electrochemical cycles. Finally, further strategies to inhibit lithium dendrite growth are proposed.