Ni,Zn-codoped spinel MgCo2O4 is in-situ grown on Co foam through a simple one-pot hydrothermal process, which acts as binder-free electrodes for supercapacitor and aqueous rechargeable Zn battery. As-prepared Ni,Zn-codoped MgCo2O4 electrode exhibits enhanced capacitance (14.43 F cm−2 or 1500 F g−1) and cycling stability (no decay of its initial capacitance after 20000 cycles), and its asymmetric supercapacitor with AC as negative electrode delivers ultrahigh rate capability, good energy density and excellent cycling durability. In addition, aqueous rechargeable Zn battery consisting of this Ni,Zn-codoped MgCo2O4 cathode and Zn anode presents ultrahigh capacity (1.93 mA h cm−2) and excellent cycling durability (no decay of its initial capacitance after 30000 cycles). This work supplies a new strategy in designing and constructing high-performance and binder-free spinel type electrode for supercapacitor and aqueous rechargeable Zn battery.