Synthesis and electrochemical properties of a new class of polymer electrolytes based on polar polysiloxane polymers is described. Unlike ethylene oxide-based polymers, these materials are oxidatively stable up to at least 4.2 V, the operating voltage of high energy cells that use cathode materials such as lithium nickel cobalt aluminum oxide (NCA) and lithium nickel cobalt manganese oxide (NCM). Use of these polymers electrolytes as an alternative to PEO in solid-state lithium batteries is described.