Lithium (Li) metal anode has attracted renewed research interests due to its high specific capacity (3860 mAh/g vs 360 mAh/g of a graphite anode) and the lowest negative potential (-3.04V vs the standard hydrogen electrode), which allows Li metal batteries to achieve high energy density when paired with the sulfur or air cathode. However, Li metal anode has safety issues and severe capacity fading. In this report, we will present a facile technique by simply adding a nano-structured interlayer onto the commercial polypropylene separator (PP) to create a composite architecture (AP). By using Li-Li symmetric cells, we will demonstrate the superior performance of AP. This unique architecture design of separator provides new insights for rechargeable lithium metal batteries, which are aimed at high energy density and cycling efficiency.