The preparation of Co3O4@MnO2 hierarchical nano-sheets for high-output potential supercapacitors

The attempt of high output potential character has always been an enormous challenge for water-based supercapacitors. In this paper, we first synthesize leaf-like Co 3 O 4 @MnO 2 nanosheets on the carbon cloth fibers (Co 3 O 4 @MnO 2 CC) with hierarchical core-shell structure via a facile chemical bath deposition at low temperature. This leaf-like Co 3 O 4 @MnO 2 nanosheets not only afford the advantage of ultra-high output potential (1.2 vs (Ag/AgCl)/V), but also carry the superiorities of ultra-high specific capacitance (616.7 F g −1 at 2 A g −1 ) and remarkable cyclic stability (83.1% retention after 10000 cycles at 20 A g −1 ). The asymmetrical supercapacitor, assembled by using Co 3 O 4 @MnO 2 @CC-90 (CoMn@CC-90) as cathode and active carbon (AC) as anode, exhibits multiple merits of extra-high output potential (2.2 V vs AC/V), splendid specific energy (54.71 W h kg −1 at power density of 1.06 k W kg −1 ) and long cycle life (86.3% capacitance retention after 10000 cycles). Our work offers one novel kind of reference for water-based supercapacitors with both characteristics of high output potential and high specific capacitance.