Ultrathin two-dimensional metal-organic frameworks (MOFs) have convincing performances in energy storage, which can be put down to their accessible active sites with rapid charge transfer. Herein, NiCo-layered double hydroxide (LDH) nanosheet arrays are used as self-sacrificial templates to in situ fabricate ultrathin NiCo-MOF nanosheet arrays on Ni foam (NS/NF) by using organic ligands without adding metal sources. Two ultrathin MOF nanosheets with different ligands, terephthalate (BDC) and 2-aminoterephthalate (NH 2 -BDC), are synthesized, characterized, and discussed in detail. Specifically, NiCo-NH 2 -BDC-MOF NS/NF exhibits the best electrochemical performance as a battery-type electrode for supercapacitors, achieves an areal capacitance of 12.13 F cm -2 at a current density of 2 mA cm -2 , and retains the original capacitance of 73.08 % after 5000 cycles at a current density of 50 mA cm -2 . Furthermore, when NiCo-NH 2 -BDC-MOF NS/NF is assembled with activated carbon (AC) to form an asymmetric supercapacitor (ASC), an energy density of 0.81 mWh cm -2 can be provided at a power density of 1.60 mW cm -2 . These results offer an effective and controllable synthetic strategy to in situ prepare ultrathin MOF nanosheet arrays with different ligands and metal ions from LDH precursors.