Improved electrochemical performance of CoOx-NiO/Ti3C2Tx MXene nanocomposites by atomic layer deposition towards high capacitance supercapacitors

Co-Ni bimetallic oxides were successfully deposited on Ti 3 C 2 T x MXene nanosheets by atomic layer deposition technology and used as pseudocapacitive materials for supercapacitors. The uniform distribution of metal oxide nanoparticles on MXene nanosheets endows the pseudocapacitive materials more active sites and the synergistic effect between CoO x and NiO greatly improves the electrochemical performance. Specifically, as the deposited cycle increased to 90, the sample showed the optimal electrochemical performance with specific capacitance up to 1960 F g −1 (1 A g −1 ), 20.3 times higher by than that of Ti 3 C 2 T x MXene, excellent rate capability (87.3% capacitance retention, 1–18 A g −1 ) and 90.2% capacitance retention after 8000 cycles.