Rational design of TiCCl MXenes nanodots-interspersed MXene@NiAl-layered double hydroxides for enhanced pseudocapacitor storage.

Although electrodes based on two dimensional hybrids with interstratification-assemble have been widely studied for supercapacitors, the performance enhancement still remains challenge mainly due to the random dispersion of surface passivated two dimensional nanosheets. Herein, a new covalent surface functionalization of MXene-based TiCCl nanodots-interspersed MXene@NiAl-layered double hydroxides (QD-TiCCl@NiAl-LDHs) hybrid electrode with superior pseudocapacitor storage performance has been elaborately designed by electrostatic-assembled. As a result, the QD-TiCCl@NiAl-LDHs electrode exhibits a super specific capacitance of 2010.8F g at 1.0 A g and high energy density of 100.5 Wh kg at a power density of 299.8 W kg. In addition, 94.1% capacitance retention is achieved after cycling for 10,000 cycles at 1.0 A g, outperforming previously reported of two dimensional hybrids electrode for supercapacitor. Furthermore, density functional theory (DFT) calculations show that the superior pseudocapacitor storage performance of the QD-TiCCl@NiAl-LDHs may be attributed to the creation of numerous electrochemical active sites and the enhancement of electrical conductivity by the QD-TiCCl MXene. This work provides new strategy for developing excellent pseudocapacitor supercapacitor based on two dimensional hybrid electrode.