Provided is a rechargeable alkali metal-sulfur cell comprising an anode active material layer, a cathode active material layer, a discrete anode-protecting layer disposed between the anode active material layer and the cathode active material layer, and an electrolyte (but no porous separator), wherein the anode-protecting layer has a thickness from 1 nm to 100 μm and comprises an elastomer having a fully recoverable tensile elastic strain from 2% to 1,000% and a lithium ion conductivity from 10−8 S/cm to 5×10−2 S/cm when measure at room temperature. The cathode layer comprises a sulfur-containing material selected from a sulfur-carbon hybrid, sulfur-graphite hybrid, sulfur-graphene hybrid, conducting polymer-sulfur hybrid, metal sulfide, sulfur compound, or a combination thereof. This battery exhibits an excellent combination of high sulfur content, high sulfur utilization efficiency, high energy density, no known dendrite issue, no dead lithium or dead sodium issue, and a long cycle life.