Ultrathin nanosheet-assembled hollow microplate CoMoO4 array derived from metal-organic framework for supercapacitor with ultrahigh areal capacitance

The rational control of metal-organic frameworks derived hollow nanomaterials with rapid mass transport and multiple active metal sites are desirable for emerging energy storage. Herein, CoMoO 4 hollow microplate array on Ni foam is prepared via a facile self-sacrificing templated strategy from ion-exchange of cobalt-organic framework microplate array. Benefiting from hollow microplate structure constructed by ultrathin nanosheets , CoMoO 4 as binder-free electrode for supercapacitor delivers ultrahigh areal capacitance/capacity (12.2 F cm −2 /6120 C cm −2  at 2 mA cm −2 ), superior rate property (82.2% at high current density of 50 mA cm −2 ) and excellent cycling stability (90.5% retention after 5000 cycles). Moreover, an asymmetric supercapacitor device is assembled by using CoMoO 4 as positive electrode and activated carbon as negative electrode , achieving high energy density of 0.321 mWh cm −2  at power density of 1.7 mW cm −2 and superior capacitance retention of 96.0% over 5000 cycles. Importantly, a blue light-emitting diode can be illuminated 2 min, indicating a great potential for practical applications. These excellent results demonstrate that this efficient strategy can extend to prepare various bimetallic oxides arrays with hollow and hierarchical microstructure for high-performance supercapacitors .