TY - JOUR
T1 - Pseudocapacitive behavior of manganese oxide in lithium-ion-doped butylmethylpyrrolidinium-dicyanamide ionic liquid investigated using in situ X-ray absorption spectroscopy
AU - Lee, Ming Tsung
AU - Li, Yun Shan
AU - Sun, I. Wen
AU - Chang, Jeng Kuei
N1 - Funding Information:
The financial support of this work by the National Science Council of Taiwan under grants 99-2218-E-008-007-MY3 and 100-2221-E-006-239-MY3 is gratefully appreciated.
PY - 2014
Y1 - 2014
N2 - Ideal pseudocapacitive behavior of α-MnO2 electrodes over a potential range of 3 V is found in lithium bis(trifluoromethylsulfonyl)imide (LiTFSI)-doped butylmethylpyrrolidinium-dicyanamide (BMP-DCA) ionic liquid (IL), which is non-flammable and has a decomposition temperature of as high as ∼300 C. Accordingly, this electrolyte is promising for high-energy, high-power, and high-safety supercapacitor applications. The addition of 0.01 M LiTFSI in the IL improves the oxide capacitance from 90 F g-1 to 120 F g-1, which is due to the incorporated Li+ ions promoting Mn valent state variation (between trivalent and tetravalent) during charge-discharge. However, excessive LiTFSI doping causes a capacitance decay due to reduced electrolyte ionic conductivity. In situ X-ray absorption spectroscopy is used to investigate the energy storage mechanism. A capacitance activation process of α-MnO2 in the Li+-doped BMP-DCA IL is found.
AB - Ideal pseudocapacitive behavior of α-MnO2 electrodes over a potential range of 3 V is found in lithium bis(trifluoromethylsulfonyl)imide (LiTFSI)-doped butylmethylpyrrolidinium-dicyanamide (BMP-DCA) ionic liquid (IL), which is non-flammable and has a decomposition temperature of as high as ∼300 C. Accordingly, this electrolyte is promising for high-energy, high-power, and high-safety supercapacitor applications. The addition of 0.01 M LiTFSI in the IL improves the oxide capacitance from 90 F g-1 to 120 F g-1, which is due to the incorporated Li+ ions promoting Mn valent state variation (between trivalent and tetravalent) during charge-discharge. However, excessive LiTFSI doping causes a capacitance decay due to reduced electrolyte ionic conductivity. In situ X-ray absorption spectroscopy is used to investigate the energy storage mechanism. A capacitance activation process of α-MnO2 in the Li+-doped BMP-DCA IL is found.
UR - https://www.scopus.com/pages/publications/84882333107
UR - https://www.scopus.com/pages/publications/84882333107#tab=citedBy
U2 - 10.1016/j.jpowsour.2013.07.088
DO - 10.1016/j.jpowsour.2013.07.088
M3 - Article
AN - SCOPUS:84882333107
SN - 0378-7753
VL - 246
SP - 269
EP - 276
JO - Journal of Power Sources
JF - Journal of Power Sources
ER -
