Superior performances of supercapacitors and lithium-ion batteries with carboxymethyl cellulose bearing zwitterions as binders

• Published in: Journal of the Taiwan Institute of Chemical Engineers Vol. 133; p. 104263
• Main Authors: Li, Wei-Cheng, Lin, Chen-Hsueh, Ho, Chih-Chi, Cheng, Tsung-Tien, Wang, Po-Hsin, Wen, Ten-Chin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2022
• Subjects: Binder; Carboxymethyl cellulose; Lithium-ion battery; Supercapacitor; Zwitterionic; Carboxymethyl cellulose; Supercapacitor; Binder; Lithium-ion battery; Zwitterionic
• ISSN: 1876-1070; 1876-1089
• DOI: 10.1016/j.jtice.2022.104263

•CMC is successfully grafted with sulfobetaine methacrylate (SBMA).•CMC-SBMA as binder will enhance the ion dissociation for less self-discharge.•CMC-SBMA as binder will regulate Li+ intercalation/deintercalation. The zwitterionic effect on binder material remains unclear. We propose that carboxymethyl cellulose (CMC) is subjected to oxa-Michael addition with sulfobetaine methacrylate (SBMA) to fabricate CMC-SBMA as binders for supercapacitor and lithium-ion battery. CMC-SBMA is certified by 1H nuclear magnetic resonance spectra with the grafting fraction of 40.5%. With zwitterionic modification, the activation energy and limiting molar conductivity of CMC-SBMA polymer electrolyte will respectively decrease to 0.058 eV and increase to 61 S.cm2/mol. Because zwitterion segment can simultaneously provide quaternary ammonium and sulfonic group respectively for electron and lithium-ion receptions, CMC-SBMA applied as binder of graphite anode for lithium-ion battery shows an extra discharging voltage plateau at 3.35 V and high specific capacitance of 140 mAh/g (LiFePO4). Meanwhile, both less decomposition of electrolyte and low reduction potential during solid electrolyte interface formation process are observed. CMC-SBMA is also applied as the binder of activated carbon electrode for supercapacitor showing low internal resistance, low diffusion parameter of 0.03, and high specific capacitance of 277.9 F/g. This study is the first to demonstrate that CMC-SBMA as a binder regulates ion transportation for the superior performance of energy storage devices. [Display omitted] Scheme1. The regulation of cation during charging and discharging process of AC electrode for supercapacitor and graphite anode for lithium-ion battery.