Interface-Modified Ti₃C₂T_x MXene/1T-WSe₂ Heterostructure for High-Capacitance Micro-Supercapacitors

As a popular electrode material in micro-supercapacitors (MSCs), MXenes are widely investigated owing to their outstanding energy storage capability. However, their unsatisfactory material structure including a confined interlayer and nanosheet restacking limit their excellent capability. Surface functional group modification and inserted layer structure are effective strategies to improve the material quality. Here, an interface-modified Ti 3 C 2 T x /1T-WSe 2 heterostructure is proposed by NH 4 + intercalation to enhance the electrochemical performance of MSCs. It is found that the induced NH 4 + during the material preparation process could embed the interlayer of Ti 3 C 2 T x so as to modify the surface with the functional group, while the 1T-WSe 2 introduces more active sites so as to form a reversible redox layer and provide sufficient pseudocapacitance. Furthermore, the prepared Ti 3 C 2 T x /1T-WSe 2 -based asymmetrical MSCs demonstrate outstanding electrochemical properties with a high operating voltage of 1.5 V and an achievable specific capacitance of 102.4 mF cm –2 . This work verifies effectively that Ti 3 C 2 T x /1T-WSe 2 is an excellent electrode material and has the wide potential application in micro-energy storage devices.