Composite layer and lithium-based battery having the same

A composite layer for use in a lithium-based battery is disclosed. The composite layer comprises a fibrous film and an inorganic additive, wherein there is a weight ratio of the fibrous film to the inorganic additive, and the weight ratio is in a range between 5:95 and 20:80. It is worth explaining that, by letting a lithium-based battery like Li metal battery be integrated with the proposed composite layer, not only does the formation of lithium dendrite be significantly suppressed, but the decomposition of electrolyte is also effectively inhibited. Moreover, the most important thing is that, by letting the lithium-based battery be integrated with the proposed composite layer, capacity retention and coulombic efficiency of the lithium-based battery are both significantly enhanced.