Sea Urchin‐Like NiCo‐LDH Hollow Spheres Anchored on 3D Graphene Aerogel for High‐Performance Supercapacitors

Abstract

To enhance the inherent poor conductivity and low cycling stability of dimetallic layered double hydroxides (LDHs) materials, designing a synergistic effect between EDLC capacitors and pseudocapacitors is an efficient strategy. In this paper, we utilized a solvothermal technique employing Co‐glycerate as a precursor to prepare sea urchin‐like NiCo‐LDH hollow spheres anchored on a 3D graphene aerogel. The unique morphology of these hollow microspheres significantly expand the specific surface area and exposes more active sites, while reducing the volume changes of materials during long‐term charging and discharging processes. The 3D graphene aerogel serves as a conductive skeleton, improving the material‘s electrical conductivity and buffering high current. The sea urchin‐like NiCo‐LDH hollow spheres anchored on 3D graphene aerogel (H‐NiCo‐LDH@GA) has a specific surface area of 51 m2 g−1 and the ID/IG value is 1.02. The H‐NiCo‐LDH@GA demonstrate a significant specific capacitance of 236.8 mAh g−1 at 1 A g−1, with a remarkable capacity retention rate of 63.1 % even at 20 A g−1. Even after 8000 cycles at 10 A g−1, the capacity retention still remains at 96.3 %, presenting excellent cycling stability.