A high-performance histidine-functionalized MWCNT-GONR/Co-Ni LDH flower cluster structural composite via a microwave synthesis for supercapacitors.

A flower cluster structural histidine-functionalized multi-walled carbon nanotube-graphene oxide nanoribbon/Co-Ni LDH (His-MW/LDH) composite was synthesized via the microwave method. In this study, we used His-MW as a carbon material to synthesize the electrode because it not only has the properties of MWCNT-GONR (MW) but also completes the N doping process due to the addition of histidine. His-MW adhered to the LDH flower cluster, and the radius of the composite was found to be nearly 1 μm. The synergistic effects of His-MW and LDH could effectively increase the specific surface areas and conductivity of the composite, thereby endowing it with high specific capacitance (1674 F g-1) and admirable cycling stability (83.33% capacitance retention). Moreover, we assembled an asymmetric supercapacitor, and it possessed 39.47 W h kg-1 at 0.80 kW kg-1 as well as prominent cycling stability (93.81% capacitance retention). This study proves the feasibility of synthesizing the histidine-functionalized carbon derivative/LDH composite by the microwave method. Moreover, we are optimistic that the electrode material can be extensively used in supercapacitors because of its splendid electrochemical properties and facile synthesis.