<p>This review summarizes recent studies on MXenes and their composites regarding energy storage and nanofluidic devices. MXenes are a new family of two-dimensional transition metal carbides and nitrides that have gained much attention in recent times due to their excellent physicochemical properties, such as its exceptionally high electrical conductivity, even more than that of metals, thermal stability, hydrophilicity, high energy and power densities, tunable structures, and large surface area along with abundant electrocatalytically active sites. These features, along with larger interlayer gaps compared with graphene, point to the emergence of MXenes as energy storage alternatives. Synthesis, properties, and applications of MXenes were comprehensively reviewed based on several theoretical and experimental studies. The applications of MXene are critically discussed in fields of nanofluids, batteries, supercapacitors, electrocatalysis, desalination, and thermal energy storage, and current trends are highlighted in these fast-evolving fields. Hence, this overall review is expected to trigger further MXene research; collaborative work by scientists will advance the energy industry.</p> Graphical abstract <p></p>