NiMn layered double hydroxide nanoarrays with high mass-loading prepared via a differentiated deposition strategy for high-performance supercapacitor electrode

Abstract

Rational construction of self-supporting electrode materials with high mass loading is important to achieve the supercapacitor electrode with excellent capacitance and high energy density. In this work, nickel-manganese layered double hydroxide (NiMn LDH) nanoarrays with high mass loading (6.27 mg cm−2) are grown on carbon cloth substrate via a novel differentiated solvo/hydrothermal deposition strategy. The architectural flexibility of the as-obtained NiMn LDH nanoarrays is regulated effectively by the variation of the precipitators and solvent. The as-obtained NiMn LDH nanoarray comprises the open channels for electrolyte access and the interconnected nanosheets decorated with tiny nanoflakes, and exhibits a high areal capacity of 3.58 C cm−2 at 5 mA cm−2 with good rate performance. The as-assembled NiMn LDH//activated carbon hybrid supercapacitor delivers a high specific capacity of 254.7 C g−1 at 1 A g−1, and achieves a high energy density of 63.5 Wh kg−1 at a power density of 900 W kg−1 with an excellent cycle stability (91.4 % capacity maintained after 10,000 cycles).