The quest for reliable and high-performance batteries has incentivized the development of new battery chemistries/materials that can potentially improve the current lithium-ion battery technologies in terms of gravimetric/volumetric energy density and safety. Polymeric ionic liquids containing both ionic liquid-like moieties and polymer frameworks are emerging as alternative electrolyte/binder candidates for Li-based rechargeable batteries, owing to their various intrinsic features, such as superior mechanical and chemical stability, structural controllability over the IL species and macromolecular backbone and leak-proof nature and thereby improved safety. In this perspective, recent progress and advances on the use of PIL-based electrolytes and binders for Li-based rechargeable batteries are overviewed and discussed, with particular focus on the structural–property relationships. Future directions and improvements of the properties of PIL-based materials are given from the standpoint of chemistry of Li-based batteries.