Overcoming the Obstacle of Polymer–Polymer Resistances in Double Layer Solid Polymer Electrolytes

Double-layer solid polymer electrolytes (DLSPEs) comprising one layer that is stable toward lithium metal and which against a high-voltage cathode are commonly suggested as promising strategy to achieve high-energy-density batteries. Through in-depth EIS analysis, it here concluded the polymer–polymer interface primary contributor electrolyte resistance in such DLSPEs consisting of polyether-, polyester-, or polycarbonate-bad SPEs. In comparison bulk ionic resistance, approximately 10-fold higher. Nevertheless, interfacial was successfully lowered by doubling salt concentration from 25 50 wt % LiTFSI owing improved miscibility at two layers.