Interlayer ionic diffusion driven in situ QDs-deposition in Co9S8-LDH hybrid supercapacitor electrode

The micro/nano-structural design of 2D-interlayers greatly enhances the electrochemical energy and kinetics as supercapacitor electrode. Herein, a hetero-Co9S8 QDs doped 2D CoNi-LDH with the proper content was constructed through diverse sulfurization times, showing 3D flower-like microsphere. The highly dispersed active QDs on 2D layers promoted both rapid ion/electron transfer kinetics and electrochemical storage capacity, which were evidenced by experiments and density function theory calculations. As a result, the assembled hybrid supercapacitor QDs-Co9S8/CoNi-LDH//activated carbon displays a maximum energy density of 33.3 Wh·kg-1 at a power density of 820.0 W·kg-1. Furthermore, the in-depth analysis of interlayer ion diffusion and formation of quantum dots in heterostructure provide a good way for synthesizing high performance electrode materials with adjustable size and composition.