In recent years, numerous discoveries and investigations have been remarked for the development of carbon-based polymer nanocomposites. Carbon-based materials and their composites hold encouraging employment in a broad array of fields, for example, energy storage devices, fuel cells, membranes sensors, actuators, and electromagnetic shielding. Carbon and its derivatives exhibit some remarkable features such as high conductivity, high surface area, excellent chemical endurance, and good mechanical durability. On the other hand, characteristics such as docility, lower price, and high environmental resistance are some of the unique properties of conducting polymers (CPs). To enhance the properties and performance, polymeric electrode materials can be modified suitably by metal oxides and carbon materials resulting in a composite that helps in the collection and accumulation of charges due to large surface area. The carbon-polymer nanocomposites assist in overcoming the difficulties arising in achieving the high performance of polymeric compounds and deliver high-performance composites that can be used in electrochemical energy storage devices. Carbon-based polymer nanocomposites have both advantages and disadvantages, so in this review, attempts are made to understand their synergistic behavior and resulting performance. The three electrochemical energy storage systems and the type of electrode materials used for them have been studied here in this article and some aspects for example morphology, exterior area, temperature, and approaches have been observed to influence the activity of electrochemical methods. This review article evaluates and compiles reported data to present a significant and extensive summary of the state of the art.

Current interest toward ionic liquids (ILs) stems from some of their novel characteristics, like low vapor pressure, thermal stability, and nonflammability, integrated through high ionic conductivity and broad range of electrochemical strength. Nowadays, ionic liquids represent a new category of chemical‐based compounds for developing superior and multifunctional substances with potential in several fields. ILs can be used in solvents such as salt electrolyte and additional materials. By adding functional physiochemical characteristics, a variety of IL‐based electrolytes can also be used for energy storage purposes. It is hoped that the present review will supply guidance for future research focused on IL‐based polymer nanocomposites electrolytes for sensors, high performance, biomedicine, and environmental applications. Additionally, a comprehensive overview about the polymer‐based composites’ ILs components, including a classification of the types of polymer matrix available is provided in this review. More focus is placed upon ILs‐based polymeric nanocomposites used in multiple applications such as electrochemical biosensors, energy‐related materials, biomedicine, actuators, environmental, and the aviation and aerospace industries. At last, existing challenges and prospects in this field are discussed and concluding remarks are provided.