Designing novel 0D/1D/2D architectural CoOx/MWCNTs/rGO hierarchically porous nanocomposite for high-performance supercapacitors

MOF-derived cobalt oxides (CoO_x) have attracted extensive attentions due to their excellent theoretical specific capacitances, permanent porosity and controllable structures. However, the inherent poor conductivity of single-component cobalt oxide, and the structural collapse, pore loss and agglomeration during pyrolysis process are still the main factors to limit the performance of CoO_x. Structure design of 3D hierarchical porous heterostructure composites through 0D/1D/2D materials is an effective strategy for boosting the capacitive performance of CoO_x. Herein, the rationally designed 3D hierarchically porous CoO_x/MWCNTs/rGO ternary hybrid composite was constructed through high-temperature pyrolysis of a facile self-assembled 0D/1D/2D Co-MOF/MWCNTs/GO precursor. Indeed, The CoO_x/MWCNTs/rGO electrode exhibited an excellent specific capacitance of 520 F g⁻¹ at 0.5 A g⁻¹, outstanding rate capability of 80.77 % capacitance retention even at 20 A g⁻¹, and ideal durability with about 8.4 % capacitance decay after 10000 cycles. Moreover, the CoO_x/MWCNTs/rGO exhibited a maximum energy density of 14.6 Wh kg⁻¹ with a power density of 41.2 W kg⁻¹.