Nanostructured Si@C/NiCo₂O₄ heterostructures for a high performance supercapacitor

As the second most abundant element on the earth, silicon exhibits excellent properties in many fields. Silicon hybrid transition metal oxides possess a low mass density and high specific capacity. To achieve the uniform dispersion of silicon in a composite, a nanostructured Si@C/NiCo₂O₄ heterostructure is fabricated via a facial hydrothermal method with silicon nanoslices encapsulated in polyacrylonitrile (PAN). The urchin-like Si@C/NiCo₂O₄ electrode exhibits excellent electrochemical properties, an efficient electron and ion transport pathway as well as the unique hybrid structure, which is useful to enhance the specific capacitance and present excellent cyclic stability (only 5.9% loss at 10 A g^-1 after 2500 cycles). The outstanding electrochemical energy storage properties of the Si@C/NiCo₂O₄ heterostructures show great potential for the next generation high-performance supercapacitors.