Preparation of 3D flower-like Ti3C2Tx microspheres by W/O emulsion-assisted assembly and their application for supercapacitors

In this study, we proposed in situ controlled preparation of 3D flower-like Ti 3 C 2 T x microspheres (FMXMSs) by water-in-oil (W/O) emulsion-assisted assembly. Polyethyleneimine (PEI), as a large molecule, can effectively stabilize the emulsion system. Ethylenediamine (EDA), as a weak cross-link agent, contains rich amino groups, which can effectively induce the assembly of Ti 3 C 2 T x in spherical droplets and eventually form 3D flower-like Ti 3 C 2 T x microspheres. By adjusting the water-oil volume ratio, the size of micro-emulsion droplets can be controlled, thus the structure and size of microspheres can finally be controlled. The structure has a large specific surface area (108.31 m 2 g -1 ) which can provide an effective ion diffusion pathway. As the supercapacitors electrode, the specific capacitance of FMXMSs is up to 224.57 F g -1 at 5 mV s -1 and 193.67 F g -1 at 0.5 A g -1 . Moreover, they also show good long-term cyclic stability. After 5000 cycles, the specific capacitance does not decay. The results indicate that W/O emulsion-assisted assembly is feasible for preparing MXenes microspheres with high electrochemical performance.