Facile synthesis of NiTe2-Co2Te2@rGO nanocomposite for high-performance hybrid supercapacitor

Abstract The design of bimetallic tellurides that exhibit excellent electrochemical properties remains a huge challenge for high-performance supercapacitors. In the present study, tellurium is consolidated on CoNi 2 @rGO for the first time, to synthesize NiTe 2 -Co 2 Te 2 @rGO nanocomposite by using a facile hydrothermal method. As-prepared NiTe 2 -Co 2 Te 2 @rGO nanocomposite was characterized by EDS, TEM, FESEM, Raman, BET, XRD, and XPS techniques to prove the structural transformation. Upon the electrochemical characterization, NiTe 2 -Co 2 Te 2 @rGO has notably presented numerous active sites and enhanced contact sites with the electrolyte solution during the faradic reaction. The as-prepared nanocomposite reveals a specific capacity of 223.6 mAh g −1 in 1.0 M KOH at 1.0 A g -1 . Besides, it could retain 89.3% stability after 3000 consecutive galvanostatic charge–discharge cycles at 1.0 A g −1 current density. The hybrid supercapacitor, fabricated by activated carbon as an anode site, and NiTe 2 -Co 2 Te 2 @rGO as a cathode site, presents a potential window of 1.60 V with an energy density of 51 Wh kg −1 and a power density of 800 W kg −1 ; this electrode is capable of lighting up two red LED lamps and a yellow LED lamp for 20 min, which is connected in parallel. The present work opens new avenues to design and fabrication of nanocomposite electrode materials in the field of supercapacitors.