Ni-Co-LDH Enfolded by N-S Co-Doped rGO for Supercapacitor Electrodes

The patent creates a composite material by growing Ni-Co-LDH nanosheets on nitrogen-doped reduced graphene oxide (rGO) nanosheets. The rGO provides high electrical conductivity while the Ni-Co-LDH maintains excellent ion-exchange properties and structural flexibility. This composite structure resolves the contradiction by combining materials with complementary properties, where the conductive rGO network enables efficient electron transport while the LDH layers facilitate ion exchange.

The patent introduces local quality variations by doping the reduced graphene oxide with nitrogen atoms at specific locations, creating regions with enhanced electrical conductivity and catalytic activity. The Ni-Co-LDH nanosheets are then grown selectively on these nitrogen-doped regions, creating a hierarchical structure where different areas serve different functions: the nitrogen-doped rGO provides conductive pathways while the LDH regions provide ion-exchange sites.

The composite structure combines high-surface-area Ni-Co-LDH nanosheets with conductive rGO nanosheets. The rGO forms a three-dimensional conductive network that provides numerous charge transfer pathways across the large surface area, reducing the overall charge transfer resistance. The LDH nanosheets maintain their large surface area for ion adsorption while the underlying rGO network ensures efficient electron transport to current collectors.

The nitrogen-doped reduced graphene oxide acts as an intermediary between the Ni-Co-LDH active material and the current collector. It provides a conductive bridge that facilitates charge transfer from the LDH nanosheets to the current collector, reducing interfacial resistance. The nitrogen dopants in the rGO further enhance this intermediary function by creating additional active sites and improving electrical conductivity.