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 Nb₂CT_x, is the most current material to emerge for energy storage applications. Nb₂CT_x 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 Nb₂CT_x MXene, scientists are working on further theoretical and experimental enhancements. The objective of this work is to deliver an outline of current breakthroughs in Nb₂CT_x 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 Nb₂CT_x 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 Nb₂CT_x MXene-based supercapacitors. This article also discusses the most recent advancements in Nb₂CT_x MXene composite-based supercapacitors.

Additive manufacturing (AM) offers many advantages for the mechanical design of metal components. However, the benefits of AM are offset to a certain extent by the poor surface finish and high residual stresses resulting from the printing process, which consequently compromise the mechanical properties of the parts, particularly their fatigue performance. Ultrasonic impact treatment (UIT) is a surface modification process which is often used to increase the fatigue life of welds in ship hulls and steel bridges. This paper studies the effect of UIT on the fatigue life of Ti-6Al-4V manufactured by Direct Metal Laser Sintering (DMLS). The surface properties before and after the UIT are characterized by surface porosity, roughness, hardness and residual stresses. Results show that UIT enhances the fatigue life of DMLS Ti-6Al-4V parts by suppressing the surface defects originating from the DMLS process and inducing compressive residual stresses at the surface. At the adopted UIT application parameters, the treatment improved the fatigue performance by 200%, significantly decreased surface porosity, reduced the surface roughness by 69%, and imposed a compressive hydrostatic stress of 1644 MPa at the surface.