Hydrothermal synthesis of Cu-doped CoS2@NF as high performance binder free electrode material for supercapacitors applications

Abstract

In current work, we are reporting the synthesis of pure and Cu doped CoS2 nanoparticles on Nickel foam by one step hydrothermal method. The physiochemical properties of Cu.CoS2 in comparison to pure CoS2 were studied with the help of XRD, FT-IR, SEM, EDX and I–V measurements. Cubic phase structure of CoS2 and Cu.CoS2 was confirmed by XRD data. Characteristics FT-IR vibrational bands revealed the presence of Co–S bonds. SEM micrographs showed cottony spherical particles of CoS2 and Cu.CoS2 with some degree of aggregation. Ohmic contacts were formed in CoS2 after doping with Cu ions, which enhanced the conductivity of Cu.CoS2 to 3.39 × 10−3 Sm−1, as compared to 8.26 × 10−6 Sm−1 for pure CoS2. When investigated for electrochemical performance, as fabricated binder free Cu.CoS2 showed outstanding supercapacitive performance with specific capacitance of 503 Fg-1 at 1 Ag-1. Additionally, Cu.CoS2 exhibited great cyclic stability with 91.1% capacity retention at 9 Ag-1 after 3000 cycles. Remarkable specific capacitance, rate capability and cyclic stability of Cu doped CoS2 can be accredited to its unique self-supporting design, morphological contributions, high conductivity and reduced grain size. Consequently, Cu.CoS2@NF electrode can act as promising candidate for energy storage applications.