Construction of core-shell heterostructure containing sandwich-like nanoarray for high-performance supercapacitors

Designing and constructing an ideal architecture is an effective approach to realize high-performance energy storage system. Core-shell heterostructure materials have attracted much attention due to their excellent per-formance in energy storage applications. Whereas, core-shell heterostructure containing sandwich-like nano -array materials have rarely been reported by far. Herein, sandwich-like NiCo-PPy-layered double hydroxide (NiCo-PPy-LDH) nanosheets with polypyrrole (PPy) as the intercalation agent were vertically anchored on 3D cross-linked graphene nanoscroll (GNS) skeleton via a hydrothermal method and subsequent in situ polymeri-zation process. Impressively, the as-prepared NiCo-PPy-LDH@GNS composite delivers a prominent specific capacitance of 2561 F center dot g-1 (equivalent conversion to 1024.4C center dot g- 1) at 1 A center dot g-1 with 82 % capacitance retention at 10 A center dot g-1. The superior electrochemical properties of the NiCo-PPy-LDH@GNS is mainly attributed to its novel heterostructure which enhances the synergistic effect between NiCo-LDHs, GNSs, and PPy. The intercalation of PPy enriches hetero-interface and active sites for the redox reaction, while the GNSs skeleton provides a 3D rigid conductive network for further enhancing charge transportation and preventing the aggregation of LDH nanosheets.