In situ polymerized Ti3C2Tx/PDA electrode with superior areal capacitance for supercapacitors

To solve the restacking of the Ti₃C₂T_x nanosheets and destroy of electrode microstructure during cycles and gain high-performance electrode for supercapacitors, Ti₃C₂T_x/PDA composite film electrode was rationally designed and successfully synthesized by one-step in situ polymerization of dopamine on the surface of the Ti₃C₂T_x nanosheets. The as-synthesized Ti₃C₂T_x/PDA composite electrode achieved a superior areal capacitance of 715 mF/cm² at a scan rate of 2 mV/s and maintained 95.5% of initial capacitance after 10000 cycles, exhibiting long-term cycling stability. The areal capacitance can be enhanced to 3440 mF/cm² when the mass loading increases to 13.6 mg/cm². The improved electrochemical performance and outstanding electrochemical stability can be attributed to the effective suppressing the restacking of Ti₃C₂T_x sheets and increasing interlayer spacing by introducing PDA, which could be beneficial to expose more surface active sites, shorten the diffusion path of electrolyte ions, promote electron transport and fast Faradaic reaction. Our work opens new design space to develop the high performance negative electrode materials.