TY - JOUR
T1 - Effect of carbon surface on degradation of supercapacitors in a negative potential range
AU - Tang, Rui
AU - Yamamoto, Masanori
AU - Nomura, Keita
AU - Morallón, Emilia
AU - Cazorla-Amorós, Diego
AU - Nishihara, Hirotomo
AU - Kyotani, Takashi
N1 - Funding Information:
To investigate a reactant included in the organic electrolytes, the reactivities of the electrolyte components (Et4NBF4, PC, and AN) were examined using a stable ionic liquid (1-Butyl-3-methylimidazolium tetrafluoroborate; BMIMBF4, FUJIFILM Wako Pure Chemical Corporation) as a support electrolyte. In addition to pure BMIMBF4, three test electrolytes were prepared: 0.26 M Et4NBF4/BMIMBF4, 4.59 M PC/BMIMBF4, and 5.18 M AN/BMIMBF4. CV scans of these electrolytes were performed at 25 ?C by using YP50F (Kuraray Chemical Co., Ltd.) as a working electrode in the same three-electrode cell set-up as described above.This work was supported by JSPS KAKENHI (grant Nos. 17H01042 and 19H00913); the Dynamic Alliance for Open Innovation Bridging Human, Environment, and Materials program; and the Network Joint Research Centre for Materials and Devices. R. T. acknowledges the China Scholarship Council for the financial support. MINECO and FEDER (CTQ2015-66080-R MINECO/FEDER) are acknowledged for financial support. The computations were performed using Research Center for Computational Science, Okazaki, Japan. The authors are thankful to Dr. Tracy Chuong for her kind suggestions on English writing.
Funding Information:
This work was supported by JSPS KAKENHI (grant Nos. 17H01042 and 19H00913 ); the Dynamic Alliance for Open Innovation Bridging Human, Environment, and Materials program ; and the Network Joint Research Centre for Materials and Devices . R. T. acknowledges the China Scholarship Council for the financial support. MINECO and FEDER ( CTQ2015-66080-R MINECO/FEDER ) are acknowledged for financial support. The computations were performed using Research Center for Computational Science, Okazaki, Japan. The authors are thankful to Dr. Tracy Chuong for her kind suggestions on English writing.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/5/1
Y1 - 2020/5/1
N2 - The stability of supercapacitors is the key factor for their use under high temperature, high voltage and long-term durability. To improve the supercapacitor stability, there is a need to understand the degradation mechanism. In this work, the degradation sites in a carbon electrode at negative potential range are investigated in two common organic electrolytes: 1 M Et4NBF4 dissolved in propylene carbonate and in acetonitrile. To elucidate the common factor over a wide range of carbon materials, we examined eight kinds of carbon materials including activated carbons, carbon blacks, zeolite-template carbon (high surface area and a large amount of carbon edge sites) and graphene mesosponge (high surface area and a little amount of carbon edge sites). Their surface structures are distinguished into two regions: carbon basal planes and edge sites by nitrogen physisorption and high-sensitivity temperature-programmed desorption up to 1800 °C. Unlike the degradation at positive potential range, initial degradation reactions at negative potential range occur mainly on the carbon basal planes rather than the edge sites. This finding is corroborated by the theoretical calculation.
AB - The stability of supercapacitors is the key factor for their use under high temperature, high voltage and long-term durability. To improve the supercapacitor stability, there is a need to understand the degradation mechanism. In this work, the degradation sites in a carbon electrode at negative potential range are investigated in two common organic electrolytes: 1 M Et4NBF4 dissolved in propylene carbonate and in acetonitrile. To elucidate the common factor over a wide range of carbon materials, we examined eight kinds of carbon materials including activated carbons, carbon blacks, zeolite-template carbon (high surface area and a large amount of carbon edge sites) and graphene mesosponge (high surface area and a little amount of carbon edge sites). Their surface structures are distinguished into two regions: carbon basal planes and edge sites by nitrogen physisorption and high-sensitivity temperature-programmed desorption up to 1800 °C. Unlike the degradation at positive potential range, initial degradation reactions at negative potential range occur mainly on the carbon basal planes rather than the edge sites. This finding is corroborated by the theoretical calculation.
KW - Basal plane
KW - Edge site
KW - Electrochemical degradation
KW - Negative potential range
KW - Supercapacitors
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U2 - 10.1016/j.jpowsour.2020.228042
DO - 10.1016/j.jpowsour.2020.228042
M3 - Article
AN - SCOPUS:85081682171
VL - 457
JO - Journal of Power Sources
JF - Journal of Power Sources
SN - 0378-7753
M1 - 228042
ER -