Since Sony commercialized the first lithium-ion batteries (LIBs) containing organic liquid electrolytes in 1991, LIBs have been widely used in portable electronic devices and more recently in vehicles. However, as the energy density and/or size of cells increases, LIBs have incurred safety concerns due to volatile and flammable organic liquid electrolytes. Therefore, the world is making an effort to replace existing liquid electrolytes with solid-state ones for high energy density and safety. NEDO of Japan forecasts that solid-state batteries will completely supersede conventional ones by 2030. Nonflammable and low-cost Amide Epoxy Polymer Electrolyte for Solid State Lithium-Ion Batteries (NAEPE), from Industrial Technology Research Institute (ITRI), is an electrolyte material with high ionic conductivity and voltage stability, which can greatly improve the safety and cycle life of LIBs. NAEPE is achieved through polymerization of liquid electrolytes with the crosslinking agent and the initiator at ambient temperatures. NAEPE provides several advantages, including high safety, low cost and easy processing and excellent cyclability.