Holey nickel hydroxide (Ni(OH)2) nanosheets with a mean thickness of 2 nm are facilely synthesized, and then embedded in carbon nanotube (CNT) scaffolds to construct a hybrid fiber electrode, which shows a high volumetric capacitance of 335.9 F cm−3 at 0.8 A cm−3 and superior rate performance. The hybrid supercapacitor made from the Ni(OH)2/CNT fiber can deliver a high specific capacitance of 24.8 F cm−3 and an energy density of 5.8 mW h cm−3 with outstanding mechanical stability under repeated bending conditions.
