Nanoscale characterization of the site‐specific degradation of electric double‐layer capacitor using scanning electrochemical cell microscopy

Electrochemical Science Advances

Hirotomo Nishihara¹  Rui Tang¹  Takeshi Fukuma²  Yusuke Kawabe²  Yosuke Miyakoshi²  Yasufumi Takahashi² 

[1] Advanced Institute for Materials Research / Institute of Multidisciplinary Research for Advanced Materials Tohoku University Sendai Miyagi Japan;Division of Electrical Engineering and Computer Science Kanazawa University Kanazawa Kakuma‐machi Japan;

关键词: electrical double‐layer capacitor;    electrochemical degradation;    HOPG;    scanning electrochemical cell microscopy;   

DOI  :  10.1002/elsa.202100053

来源: DOAJ

【 摘 要 】

Abstract Electric double‐layer capacitors (EDLCs) that store electrical energy in the interface between an electrolyte and a solid electrode are favorable energy storage systems that demonstrate high‐power density, excellent cycle stability, and low environmental impact. To increase the operating voltage and improve the capacitance of EDLCs, it is essential to investigate the relationship between the degradation process and structural properties of activated carbon. In the current study, we used scanning electrochemical cell microscopy (SECCM) to assess the site‐specific degradation mechanisms caused by electrolyte decomposition. To simplify the structural properties of activated carbon, we used the highly oriented pyrolytic graphite (HOPG) as a model substrate to distinguish the edge and the basal planes of activated carbon. The mobile and nanoscale electrochemical cell provides local cyclic voltammetry (CV) to examine the difference in the degradation process at the edge and basal planes of HOPG. SECCM's nanoscale electrochemical cell can suppress the impact of capacitive current and can therefore be used to clearly measure the current associated with degradation caused by electrolyte decomposition. SECCM's local CV measurements directly exposed the degradation reaction that occurred at the edge plane in the positive potential range.

【 授权许可】

Unknown