Design of nickel cobalt molybdate regulated by boronizing for high-performance supercapacitor applications

Nickel-cobalt-based molybdates have been intensively investigated because of their high theoretical specific capacitance and multifarious oxidation states. Here, we have successfully synthesized hierarchical structures (Ni3B/Ni(BO2)(2)@NixCoyMoO4) by boronizing Ni(x)Co(y)MoO(4)nanosheets on flexible carbon cloth substrates. Benefitting from the synergistic effect among Ni3B, Ni(BO2)(2)and Ni(x)Co(y)MoO(4)in hybrid architectures, the electrode material possesses higher capacity of 394.7 mA h g(-1)at 1 A g(-1)and a good rate performance (309.5 mA h g(-1)maintained at 20 A g(-1)). Then, a hybrid supercapacitor assembled with Ni3B/Ni(BO2)(2)@Ni(x)Co(y)MoO(4)and activated carbon as the positive and the negative electrode, displays a high specific capacitance of 370.7 F g(-1)at 1 A g(-1)(210 F g(-1)at 10 A g(-1)), a high voltage of 1.7 V, and a high energy density of 131.8 W h kg(-1)at the power density of 800 W kg(-1)(still 74.7 W h kg(-1)maintained at 8000 W kg(-1)). This study widens the research scope of boronizing pseudocapacitance materials and reveals a high application potential of Ni3B/Ni(BO2)(2)@Ni(x)Co(y)MoO(4)for energy storage devices in the future.