3D flower-like MOF-derived NiCo-LDH integrated with Ti3C2Tx for high-performance pseudosupercapacitors

Nickel cobalt layer double hydroxides (NiCo-LDH) have high theoretical capacity for energy storage, but suffer from low electrical conductivity and sluggish charge transfer kinetics. Herein, three-dimensional (3D) porous flower-like NiCo-LDH/Ti3C2Tx is facilely fabricated via the electrostatic self-assembly of metal-organic frameworks and Ti3C2Tx followed by the ion-exchange reaction. The as-prepared NiCo-LDH/Ti3C2Tx-5 delivers a high specific capacity of 635.7 C g−1 at 1 A g−1, and still remains 382.3 C g−1 at 20 A g−1. Furthermore, the corresponding asymmetric supercapacitor coupled with activated carbons achieves high energy density of 44.6 W h kg−1 under the power density of 852.5 W kg−1, and indicates remarkable cycling performance (85.71% of capacitance retention after 10,000 cycles). The outstanding electrochemical performance is assigned to 3D porous structure and high electrical conductivity, which not only increases the contract area between electrodes and electrolyte, but also enhances the ion diffusion and charge transfer kinetics.