Effect of soft template on nickel-cobalt layered double hydroxides grown on nickel foam as battery-type electrodes for hybrid supercapacitors

Abstract

Nickel-cobalt layered double hydroxides (NiCo-LDHs) are successfully synthesized on nickel foam by the simple hydrothermal process, with polyvinylpyrrolidone (PVP), cetyltrimethyl ammonium bromide (CTAB), polyvinyl alcohol (PVA), and sodium dodecyl sulfate (SDS) as template agents, respectively. The prepared NiCo-LDHs present different morphology and outstanding electrochemical performances. Particularly, the NiCo-LDHs samples with CTAB as template agents (NC-C) exhibit high specific capacity (869.48 C g−1 at 1 A g−1) and excellent durability (88.23% capacity retention after 2000 cycles). Furthermore, the hybrid supercapacitors (HSCs) device based on NC-C and activated carbon electrodes deliver an energy density of 48.34 Wh kg−1 at a power density of 799.84 W kg−1 and satisfactory cycle stability (90.83% capacity retention after 2000 cycles). These properties indicate that the prepared materials could become ideal electrode materials for asymmetric supercapacitors.