In the present work, we have demonstrated the rapid synthesis of Ag dendrites on carbon nanotubes (CNTs) wrapped CuCo2O4 nanoflowers (CNT-CuCo2O4@Ag) by using a two-step chemical approach. The as-synthesized CNT-CuCo2O4@Ag is used as an electrode for supercapattery application. Individually, CNT-CuCo2O4@Ag electrode shows the exceptional capacity of 590 mAh g−1 at a current density of 0.5 A g−1. This capacity is 1.8 and 1.6 times those of the pure CuCo2O4 and CNT-CuCo2O4 nanoflower-based electrodes, respectively. Furthermore, an all-solid-state asymmetric supercapattery (ASC), CNT-CuCo2O4@Ag//AC, has been fabricated using the CNT-CuCo2O4@Ag nanoflowers as the positive electrode and a thermocol-derived activated carbon (AC) as the negative electrode. Interestingly, the ASC device delivers an ultrahigh energy density of 91 Wh kg−1 at the power density of 0.42 kW kg−1; even at the high power density of 18 kW kg−1, the ASC device still maintains an energy density of 50 Wh kg−1. The ASC device also exhibits excellent cyclic stability by showing 98% of capacity retention over 20,000 cycles at a high current density of 10 A g−1. This rapid in situ synthesis strategy for Ag dendrite growth and CNT wrapping is also applicable to other metal oxides and metal sulphides with porous nanostructures containing NH3 molecules.