Effective synthetic strategy of Zn0.76Co0.24S encapsulated in stabilized N-doped carbon nanoarchitecture toward ultra-long-life hybrid supercapacitors
Hollow Zn0.76Co0.24S@N-doped carbon (HZCS@NC) electrode with abundant hierarchical pores synthesized by a continuous ingenious method is presented for the demand of high-performance supercapacitors. The formation mechanism of the hollow structure in which the Zn0.76Co0.24S nanoparticles embedded in a nitrogen-doped carbon layer was analyzed in this work. This electrode eshibits an excellent specific capacity of 937 C g-1 at 1 A g-1 and a satisfying capacity retention rate of about 112% after 40000 cycles at a rate of 5 A g-1. Such preeminent performance is realized via (1) the short electrolyte diffusion length within the hollow structure, (2) the high electrochemical activities provide by the bimetallic sulfide and heteroatom doping, (3) the consummate combination of faradaic and electric double layer materials, and (4) the conductive network with multiple holes. The electrochemical performance evaluation of the assembled HZCS@NC//RGO hybrid supercapacitor (HSC) was also executed. Impressively, the HSC gives a satisfactory energy density of 55.47 Wh kg-1, a maximum power density of 16.55 kW kg-1, and even an ultra-long (100000) cycling life (108% retention of the initial capacity). This study presents a novel strategy of engineering stable polyporous multicomponent hollow structures to fabricate the prospective energy storage devices.