Aluminum sulfate-an electrolyte for MnO2 hybrid supercapacitor

作者：Chen Tal; Peled Emanuel^*

来源：Journal of Solid State Electrochemistry, 2017, 21(11): 3325-3331.

DOI：10.1007/s10008-017-3673-5

• Aluminum sulfate
• Manganese dioxide
• Supercapacitor
• MnO2

Manganese oxide is an important emerging electrode material for use in supercapacitor applications. Herein, we propose a new aqueous electrolyte, Al-2(SO4)(3), for use with this type of supercapacitor. We hypothesize that the trivalent aluminum ion will demonstrate higher specific capacities because of its higher charge. We show that beta-MnO2, which usually demonstrates low specific capacity (similar to 10 F g(-1)), is highly active in this electrolyte. At a scan rate of 2 mV s(-1), a specific capacity of 185 F g(-1) is demonstrated. An asymmetric cell is constructed from a positive beta-MnO2 electrode and an activated carbon (AC) negative electrode. The cell exhibits an initial specific capacity of 42 F g(-1) (calculated for the total AC and MnO2 mass), and a steady coulombic efficiency (9798%), operating for 2500 cycles, after which a 20% drop from its initial capacity is measured. The cell displays higher values of specific capacitance when compared to a sodium sulfate electrolyte.

• 出版日期2017-11