Next generation consumer electronics require increasingly more powerful, longer lasting, and safer rechargeable batteries. Lithium metal batteries (LMBs), with their high theoretical energy density, could meet this demand. However, the tendency of lithium to form dendrites is a well-known barrier to commercialization of the technology. We developed cross-linked poly(ethylene oxide) networks enabled by thiol-ene click chemistry and determined that “soft,” but highly uniform networks could suppress lithium dendrites by regulating the deposition of lithium. By hosting a liquid electrolyte in the pores of the networks, the polymer gel electrolytes were found to be more effective than their liquid electrolyte or solid polymer network components in LMB full cell studies. The polymer gel electrolytes were redesigned to be simple and adaptable to large scale manufacturing and were tested in challenging full-cell and pouch-cell battery configurations with excellent long-term stability. Finally, a novel cross-linked polymer-and-water-in-salt (PAWS) composition was developed and studied for application in aqueous lithium batteries.