Additive assisted electrodeposition of nanostructured nicose2 for high performance asymmetric supercapacitor

Abstract Micro/nano structure shape-controlled synthesis is critical to many applications of physics and chemistry. For the sake of control the self-assembly and morphology of NiCoSe2 (NCSe) nanostructure through electrodeposition, polyethylene glycol (PEG) is chosen as an additive to improve the bottom-up filling behavior of NCSe nanostructure while maintaining its roughness feature. The effects of PEG on morphology and electrochemical property of NCSe electrode are examined. Experiment results indicate that NCSe nanostructure prepared with 10% (w/v) PEG concentration offers an improved specific capacity of 480.5 mA h g–1 at current density of 2 A g–1 (325.5 mA h g–1 of NCSe without PEG assisting at the same current density). Additionally, the asymmetric supercapacitor (ASC) device constructed with NCSe prepared under the assist of PEG as a positive electrode displays a high specific energy of 44.5 Wh kg–1 as well as a long cycling life (92.1% capacity retention after 10,000 cycles).