High Ion Conducting Dobule Network Crosslinked Gel Polymer Electrolytes for High‐Performance Supercapacitors

Abstract

As the demand for electrical energy storage devices increases, various electrolytes are being studied. In particular, gel polymer electrolytes (GPEs) with excellent physical properties can improve safety and cycle life, so attempts are underway to replace organic liquid electrolytes facing fire or explosion issues. However, the intrinsic poor electrochemical properties of GPEs limit their commercialization in all-solid-state energy storage devices. In an attempt to solve this problem, epoxy/poly(ethylene glycol) (PEG)-based double network electrolytes (DNEs) containing a mixture of bis(trifluoromethane)sulfonimide lithium salt (LiTFSI) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) are designed to enhance the electrochemical properties of traditional single network electrolytes (SNEs). The synthesized epoxy/PEG-based DNE has higher mechanical strength (G′ = 1.7 MPa) with outstanding ionic conductivity (𝝈 DC ≈ 5.8 × 10 −4 S cm −1 ) at room temperature, compared to the epoxy-based SNE. Then, an all-solid-state supercapacitor based on the DNE and activated carbon electrodes exhibits higher specific capacitance (≈153 F g −1 ) and power density (833 W kg −1 ), compared to the SNE-based supercapacitor.

In situ-fabricated quasi-solid polymer electrolytes incorporating an ionic liquid for flexible supercapacitors

“…The characteristic peak at ∼1728 cm −1 belonged to the C]O originating from PEGDMA, which provided good affinity between the polymer skeleton and the electrolyte. 27 It is noteworthy that the characteristic peaks of AN (2260 cm −1 for -CN group), 29 PC (1780 cm −1 for aliphatic ketone group), 30 and IL (1347 and 1175 cm −1 for the TFSI anion; 3100-3160 cm −1 for the imidazolium cation) 31 appeared in the fabricated P2A or P2P as well, suggesting that considerable amounts of the organic solvents and IL were still retained in the | Sustainable Energy Fuels, 2024, 8, 358-368…”

Glass Fiber Reinforced Epoxy-Amine Thermosets and Solvate IL: Towards New Composite Polymer Electrolytes for Lithium Battery Applications

“…DSC analysis ( Figure 3 a) confirmed that both composite membranes are completely polymerized, by the absence of residual heat or an exothermal peak, in agreement with previous observations by ATR-FTIR. In addition, negative glass transition temperatures (T g ) of −58 °C and −59 °C were found for CGPE-GFA and CGPE-GFW, respectively, which, combined with the presence of amorphous phases, are essential for delivering a high ionic conductivity by segmental motion of the ethylene oxide chains above T g [ 27 ]. In this case, it is expected that at room temperature both membranes could provide appropriate Li + ion hopping, and a high ionic conductivity.…”