Convenient room-temperature synthesis of sulfur and nitrogen co-doped NiCo-LDH coupled with CNTs on NiCo foam as battery-type electrode for high performance hybrid supercapacitor

The convenient synthesis of the composite electrode with high supercapacitance performance plays an important role in practical application but is challenging.Herein,the carbon nanotubes(CNTs)coupled with lowcrystalline sulfur and nitrogen co-doped Ni Co-LDH(denoted as SN-Ni Co-LDH)nanosheets array are grown on Ni Co foam(NCF)substrate by two convenient steps of metal induced self-assembly and corrosion engineering,which present the advantages of operating at roomtemperature and low preparation costs.Benefiting from the S–N co-doping and low-crystallinity of Ni Co-LDH,the prepared SN-Ni Co-LDH@CNTs@NCF electrode presents a topping charge capacity of 2470 C·g^(-1)(4.94 C·cm^(-2))at 5 m A·cm^(-2).Furthermore,the fabricated asymmetry supercapacitor(ASC)achieves an extraordinary energy density of 77 Wh·kg^(-1)(0.617 m Wh·cm^(-2))at a power density of 438 W·kg^(-1)(3.5 m W·cm^(-2))and outstanding stability(91%capacity retention after 5000 cycles at20 m A·cm^(-2)).Impressively,the structure evolution of Ni Co-LDH during the charge/discharge processes has been thoroughly elucidated by in-situ Raman spectra.Therefore,this work verifies a powerful strategy and practical value for preparing composite electrodes with high supercapacitance performance,and also provides guidance for the rational design of the smart electrodes.