Infilling of highly ion-conducting gel polymer electrolytes into electrodes with high mass loading for high-performance energy storage

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 87; pp. 173 - 179
• Main Authors: Song, Eunseok, Shin, Joobee, Lee, Soo-Hyoung, Kim, Sung-Kon
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.07.2020; 한국공업화학회
• Subjects: Charge transport; Energy storage; Flexible devices; Gel polymer electrolyte; Supercapacitor; 화학공학; Supercapacitor; Charge transport; Flexible devices; Gel polymer electrolyte; Energy storage
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2020.03.039

[Display omitted] •Infilling of gel polymer electrolytes into thick electrodes with high mass loadings was performed.•Via the infilling, large extent of electrical double layers was formed.•The process led to excellent rate performance and energy density.•The flexible device provided reliable power output under electrochemical and mechanical stresses. Full utilization of electrodes toward high-performance energy storage is challenging in cases where electrode/electrolyte interface is significant. From a practical perspective, this is particularly important in cases where a thick electrode or one with a high mass loading is needed. Here, we report an approach to increase the electrode performance by the infilling of a highly ion-conductive organic gel polymer electrolyte (EI-GPE, ionic conductivity ∼9.2mScm−1) into a multi-walled carbon nanotube (MWCNT) electrode with high mass loadings of up to 26mgcm−2 (or significant thicknesses of up to 443μm). Typical GPE (t-GPE) with a film-forming property but moderate ionic conductivity (1.2mScm−1) is then placed over the EI-GPE-filled electrode surface, resulted in flexible supercapacitor. Infilling of EI-GPE into MWCNT electrode provides a large-ion accessible interface that affords the increase in volumetric capacitance and energy density, about sixfold greater than that of the typical supercapacitors configured by sandwiching t-GPE as both electrolyte and the separator between a pair of electrodes. Importantly, this method enables scaling of the areal capacitance with electrode thickness (or mass loading of active material). A pouch type EI-SC provides stable performance after bending, suggesting it holds the promise of flexible energy storage.