Epoxidized natural rubber‐graft‐acrylonitrile (ENR‐g‐ACN)‐based solid polymer electrolytes for energy storage application

Abstract

In situ UV‐initiated polymerization was performed to prepare solid polymer electrolytes (SPEs) based on epoxidized natural rubber‐graft‐acrylonitrile (ENR‐g‐ACN) by employing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as a doping salt. A solid‐state lithium‐ion battery (SSLIB) was fabricated using ENR‐g‐ACN‐LiTFSI as an electrolyte and lithium metal and graphite as electrodes. The SSLIB's performance was evaluated to investigate the electrochemical stability window (ESW), redox behavior, voltage stabilization measurement and electrochemical capacitance response. The ESW of the SPE reached a reasonable value of 5.6 V (vs Li/Li+). The absence of redox peaks on the cyclic voltammetry (CV) curve indicates that the cell behaved more like a capacitor than a battery. At an open‐circuit voltage of 2.78 V, the battery's performance also showed a low capacity due to parasitic (unwanted) reactions, electrolyte degradation or the battery's age. The performance of an electrical double‐layer capacitor (EDLC) was also analyzed by linear sweep voltammetry, CV and galvanostatic charge–discharge. The ESW of the SPE was obtained as 2.7 V. The specific capacitance of the EDLC was found to be 6 F g−1 at 0.005 mA cm−2 and 60 °C. The fabrication of affordable and secure SSLIBs and EDLCs with the use of rubber materials will be successful if this strategy is developed. © 2023 Society of Industrial Chemistry.