In-situ Ni-doped V-MOF ultra-thin nanosheet arrays on Ni foam for high-performance hybrid supercapacitors

Bimetallic organic frameworks possess distinctive structural and component benefits that make them essential materials for energy storage devices with outstanding capabilities. Here, ultra-thin 2D VNi-MOF nanosheet arrays (NSAs) have been in-situ grown on nickel foam (NF) which served as both the current collector and the Ni source by pretreatment and one-step solvothermal method and used as an efficient electrode material for high performance supercapacitors. Benefiting from its ultra-thin 2D NSAs structure and the synergy of bimetallic ions, the VNi-MOF NSAs/NF exhibits a high specific capacity performance (516.5 C g⁻¹ at 1 A g⁻¹) and outstanding cycling stability (85.6 % capacity retention over 12, 000 cycles at 20 A g⁻¹). Battery-type VNi-MOF NSAs/NF and capacitive-type AC are integrated to assemble a HSC. The prototype HSC achieves a remarkably high energy density of 43 Wh kg⁻¹ (at 800 W kg⁻¹), which demonstrates the great potential of VNi-MOF (bimetallic organic framework) as a HSC electrode.