Urchin-Like Ni_1/3Co_2/3(CO₃)_1/2(OH)·0.11H₂O for Ultrahigh-Rate Electrochemical Supercapacitors: Structural Evolution...

Portable electronics and electric or hybrid electric vehicles are developing in the trend of fast charge and long electric mileage, which ask us to design a novel electrode with sufficient electronic and ionic transport channels at the same time. Herein, we fabricate a uniform hollow-urchin-like Ni_1/3Co_2/3(CO₃)_1/2(OH)·0.11H₂O electrode material through an easy self-generated and resacrificial template method. The one-dimensional chain-like crystal structure unit containing the metallic bonding and the intercalated OH^- and H₂O endow this electrode material with abundant electronic and ionic transport channels. The hollow-urchin-like structure built by nanorods contributes to the large electrode-electrolyte contact area ensuring the supply of ions at high current. CNTs are employed to transport electrons between electrode material and current collector. The as-assembled NC-CNT-2//AC supercapacitor device exhibits a high specific capacitance of 108.3 F g^-1 at 20 A g^-1, a capacitance retention ratio of 96.2% from 0.2 to 20 A g^-1, and long cycle life. Comprehensive investigations unambiguously highlight that the unique hollow-urchin-like Ni_1/3Co_2/3(CO₃)_1/2(OH)·0.11H₂O electrode material would be the right candidate for advanced next-generation supercapacitors.