This paper discusses the development of SPEs, ionic liquids as electrolytes in lithium-ion batteries, and focuses on the benefits related to using them over liquid electrolytes. PEO-based SPEs increase ionic conductivity, improve thermal stability, and ensure safety without leakage and combustion hazards. Ionic liquids enhance lithium-ion mobility and mechanical stability within the high energy density application in electric vehicles and consumer electronics. The study puts forward an additional role of thermal and electrochemical stability that impacts performance and life span of batteries. The different approaches through modification of ionic conductivity at ambient temperature are explored, including the introducing plasticizers and inorganic fillers. In general, the ionic liquid-based SPEs represent a significant step forward in the battery technology landscape with more promising efficient, safer energy storage solutions on the cards.