The design of heterostructured pseudo-capacitive materials plays a key role in fabricating asymmetric supercapacitors (ASCs) with high energy density and electrochemical cycle life for the evolution of next-generation energy storage devices. Use of ZnCo2O4 nanoflakes covered with MnO2 nanosheets led to a synergistic effect that produced a larger electroactive surface area for charge storage than that provided by bare ZnCo2O4 nanoflakes or MnO2 nanosheets. The ZnCo2O4 nanoflakes served as the backbone for the growth of the MnO2 nanosheets. The ZnCo2O4-MnO2 heterostructure was synthesized on Ni foam using a combined binder-free electrodeposition and hydrothermal method. The electrode formed using this unique method showed a maximum specific capacitance of 2057 F g(-1) at a current density of 1 A g(-1) with a rate capability of 65% even after a 15-fold increase in current density. Moreover, the electrode showed a cycling stability of 96.5% after 5000 successive cycles at a current density of 15 A g(-1). An ASC formed using ZnCo2O4-MnO2 as the positive electrode and activated carbon as the negative electrode delivered a maximum energy density of 69Wh kg(-1) with 93.5% capacity retention after 5000 cycles. Further, an experiment to investigate the commercial application of ASCs was conducted. (C) 2018 Elsevier Ltd. All rights reserved.