Preparation and characterization of novel 2D/3D NiSe2/MnSe grown on rGO/Ni foam for high-performance battery-supercapacitor hybrid devices

Reasonable choice of electrode materials and rational design of structures are two effective means to improve the electrochemical properties of supercapacitors. Herein, a series of NiSe2/MnSe (NMSe) battery-type electrode materials with different morphologies are attached to reduced graphene oxide (rGO)-coated Ni foam (NF) through controlling the selenization reaction temperature (NMSe/rGO). Benefiting from the unique 2D/3D architecture with 2D nanosheets and 3D nanospheres, the synergistic effects between the composites as well as the high electrical conductivity of rGO, the obtained electrode delivers the optimum electrochemical performance after selenization at 140 degrees C (NMSe/rGO-140). As a result, the NMSe/rGO-140 composite displays ultrahigh specific capacity of 1450.7 C g(-1) at 1 A g(-1) along with the advantageous long cycle stability of 87% at 10 A g(-1) over 8000 cycles. Moreover, a battery-supercapacitor hybrid (BSH) device prepared using NMSe/rGO-140 (positive) and active carbon (negative) exhibits a maximum energy density of 51.4 W h kg(-1) at 800.7 W kg(-1) combined with outstanding capacity retention of 100% through 8000 cycles. With such prominent electrochemical behaviors, the NMSe/rGO-140//AC BSH possesses great potential utilization for high-energy storage devices.

Automated summary

Reasonable choice of electrode materials and rational design of structures are effective ways to improve the electrochemical performance of supercapacitors. The NiSe2/MnSe electrode materials attached to reduced graphene oxide-coated Ni foam through controlling the selenization reaction temperature exhibit optimal electrochemical performance. The resulting electrode delivers ultrahigh specific capacity and long cycle stability, making it a promising candidate for high-energy storage devices.