Interface-Modified Ti3C2Tx 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 Ti3C2Tx/1T-WSe2 heterostructure is proposed by NH4+ intercalation to enhance the electrochemical performance of MSCs. It is found that the induced NH4+ during the material preparation process could embed the interlayer of Ti3C2Tx so as to modify the surface with the functional group, while the 1T-WSe2 introduces more active sites so as to form a reversible redox layer and provide sufficient pseudocapacitance. Furthermore, the prepared Ti3C2Tx/1T-WSe2-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 Ti3C2Tx/1T-WSe2 is an excellent electrode material and has the wide potential application in micro-energy storage devices.