MXenes are progressively evolving two-dimensional (2D) materials with an expanding wide range of applications in the field of energy storage. They rank among the best electrode materials for cutting-edge energy storage systems. Energy storage device performance is greatly enhanced by MXenes and their composite materials. As technology has improved over the last several decades, the demand for high-capacity energy storage devices that are versatile, sturdy, and have cheap production costs has increased. MXene, which is based on Nb2CTx, is the most current material to emerge for energy storage applications. Nb2CTx MXene is now the most sought-after material in the 2D family due to its flexibility, high conductivity, superior electrochemical nature, superior hydrophilicity, tunable surface functional groups, great mechanical properties, and 2D layered structure. Examples include gas and biosensors, water splitting, water purification, antimicrobial coatings, electromagnetic interference shielding, and transparent electrical conductors. Because of the distinctive properties of Nb2CTx MXene, scientists are working on further theoretical and experimental enhancements. The objective of this work is to deliver an outline of current breakthroughs in Nb2CTx MXene for the construction of robust, flexible, and highly effective electrochemical energy storage devices powered by supercapacitors. Deep research has been conducted on the structure of Nb2CTx MXene, as well as on different synthesis techniques and their distinctive properties. The emphasis has also been placed on how various aspects, such as electrode architecture design, electrolyte composition, and so on, influence the charge storage device and electrochemical efficiency of Nb2CTx MXene-based supercapacitors. This article also discusses the most recent advancements in Nb2CTx MXene composite-based supercapacitors.