Effect of carbon surface on degradation of supercapacitors in a negative potential range

JOURNAL OF POWER SOURCES

卷:457

Article

Tang, Rui¹  Yamamoto, Masanori¹  Nomura, Keita¹  Morallon, Emilia^2,3  Cazorla-Amoros, Diego^2,3  Nishihara, Hirotomo¹  Kyotani, Takashi¹ 

[1] Tohoku Univ, Inst Multidisciplinary Res Adv Mat, Aoba Ku, 2-1-1 Katahira, Sendai, Miyagi 9808577, Japan

[2] Univ Alicante, Dept Quim Inorgan, Apartado 99, E-03080 Alicante, Spain

[3] Univ Alicante, Inst Univ Mat, Apartado 99, E-03080 Alicante, Spain

关键词: Supercapacitors;    Electrochemical degradation;    Negative potential range;    Edge site;    Basal plane;   

DOI  :  10.1016/j.jpowsour.2020.228042

来源: Elsevier

【 摘 要 】

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 degrees 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.

【 授权许可】

Free