Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 8, Issue 28, Pages 18078-18088Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.6b04883
Keywords
manganese oxides; cycling stability; dissolution issue; morphology transformation; supercapacitor
Funding
- Natural Science Foundation of China [51301162, 21503065]
- China Postdoctoral Science Foundation [2015M571924]
Ask authors/readers for more resources
Long cyclic life is very important to the practical application of the pseudocapacitors. A systematic study has been carried out to reveal what key factors and how they affecting the cycling behaviors of manganese oxides. The specific capacitance degradation of MnOx is usually attributed to the so-called dissolution issue. Our results indicate that dissoluted MnOx is in the form of the flotsam derived from the detached active materials instead of Mn2+ in the solution, which causes color change of electrolyte and the loss of specific capacitance. During the cycling, the morphology of manganese oxides transformed to flower-like flakes regardless of the starting structures. After that, it tends to form nanowires especially at elevated temperatures. According to the relative low electrochemical utility of nanowires, specific capacitance might decrease at this stage. These results put forward new questions on charge storage mechanism. Besides, electrochemical oxidation of MnOx leads to an increase in specific capacitance. The cycling behavior of MnOx is mainly determined by these three factors. Excitingly, a very stable cycling performance with no capacitance degradation over 40 000 cycles has been achieved in MnOx hierarchical sphere-based electrodes. This study provides insightful understanding of the fundamental cycling behavior of MnOx-based electrodes and useful instructions for developing highly stable supercapacitors.
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