Transition metal sulfide-laminated copper wire for flexible hybrid supercapacitor

In this paper, we propose a flexible wire-type hybrid supercapacitor (FWHSC) endowed with superior electrochemical properties of transition metal sulfide nano-flakes. The electrodeposition method was conducted for coating of electroactive transition metal sulfide (CoS, NiCo2S4, CoS/NiCo2S4 and ZnCo2S4) nanomaterials on the current collector (Cu-wire), which makes it possible to store the electrochemical energy. The electrochemical study of NiCo2S4 and ZnCo2S4 electrodes revealed excellent charge storage features with areal capacitance of 245.5 and 104.6 mF cm(-2), respectively, at a scan rate of 2 mV s(-1). The FWHSC assembled from Cu@CoS/NiCo2S4 and Cu@ZnCo2S4 electrodes and KOH/PVA gel electrolyte operates in a voltage range of 1.5 V and delivers a specific energy of 6 W h kg(-1) at the specific power of 4500 W kg(-1) and a cycling stability of over 2000 cycles.