In recent years, much effort has been devoted to the development of supercapacitors (SCs) for energy storage and conversion systems. In this research work, a series of novel transition metal nanostructures were successfully fabricated and directly employed as advanced binder-free electrodes for all-solid-state asymmetric supercapacitors (ASCs). In chapter one, different types of SCs, electrode materials as well as the electrolytes are briefly introduced.In chapter two, a novel strategy is presented for the direct growth of 3D hierarchical CoO@MnO2 core-shell nanostructure on Ni foam. The 3D CoO@MnO2 core-shell nanostructure exhibited an ultrahigh specific capacitance (1835 F g−1 at a current density of 1 A g−1), excellent rate capacity, and excellent outstanding cycling stability (97.7% of capacitance retention after 10000 cycles). Moreover, an ASC device was also assembled with the 3D CoO@MnO2 core-shell nanohybrid as the positive electrode and nitrogen-doped graphene (NG) as the negative electrode. The ASC delivered a high specific capacitance of 191 F g−1 at a current density of 1 A g−1, tremendous energy density of 85.9 Wh kg−1, and remarkable cycling stability of 86.8% capacitance retention after 10000 cycles.In chapter three, a facile strategy has been developed to synthesize the hierarchical Zn–Co–S nanowires (NWs) on Ni foam. When studied in a three-electrode configuration, Zn–Co–S NWs held an ultrahigh areal capacity of 0.9 mAh cm−2 at a current density of 3 mA cm−2, with an outstanding rate capability and cycling stability of 93.2% of capacity retention after 10000 cycles. Remarkably, the as-assembled Zn–Co–S NWs//Fe2O3@rGO ASC yields an ultrahigh volumetric capacity of 1.98 mAh cm−3 at a current density of 3 mA cm−2, excellent energy density of 81.6 Wh kg−1 at a power density of 559.2 W kg−1, and exceptional cycling performance of 92.1% of initial capacity retention after 10000 cycles. In chapter four, a cost-effective strategy was presented to fabricate the hierarchical Mn–Ni–S nanosheet arrays (NAs) on Ni foam. When evaluated as a cathode in a three-electrode configuration, Mn–Ni–S NAs (1:2) delivered an ultrahigh areal capacity of 0.687 mAh cm−2 at a current density of 3 mA cm−2, with an excellent cyclic stability (94.9% of initial capacity retention after 10000 cycles). Furthermore, the as-assembled Mn–Ni–S NAs//Fe2O3@rGO ASC device delivered a remarkable energy density of 76.6 W h kg−1 at a power density of 325.4 W kg−1, an outstanding cycling performance (93.4% of capacity retention after incessantly 10000 cycles).