Journal
ACS NANO
Volume 4, Issue 10, Pages 5835-5842Publisher
AMER CHEMICAL SOC
DOI: 10.1021/nn101754k
Keywords
graphene; manganese oxide; composite; asymmetric; electrochemical capacitor
Categories
Funding
- Ministry of Science and Technology of China [2006CB932703]
- National Science Foundation of China [50872136, 50921004, 50632040]
- Chinese Academy of Sciences [KJCX2-YW-231]
Ask authors/readers for more resources
In order to achieve high energy and power densities, we developed a high-voltage asymmetric electrochemical capacitor (EC) based on graphene as negative electrode and a MnO2 nanowire/graphene composite (MGC) as positive electrode in a neutral aqueous Na2SO4 solution as electrolyte. MGC was prepared by solution-phase assembly of graphene sheets and alpha-MnO2 nanowires. Such aqueous electrolyte-based asymmetric ECs can be cycled reversibly in the high-voltage region of 0-2.0 V and exhibit a superior energy density of 30.4 Wh kg(-1), which is much higher than those of symmetric ECs based on graphene//graphene (2.8 Wh kg(-1)) and MGC//MGC (5.2 Wh kg(-1)). Moreover, they present a high power density (5000 W kg(-1) at 7.0 Wh kg(-1)) and acceptable cycling performance of similar to 79% retention after 1000 cycles. These findings open up the possibility of graphene-based composites for applications in safe aqueous electrolyte-based high-voltage asymmetric ECs with high energy and power densities.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available