Allyl ethers as combined plasticizing and crosslinkable side groups in polycarbonate‐based polymer electrolytes for solid‐state Li batteries

Abstract

Allyl ether-functional polycarbonates, synthesized by organocatalytic ring-opening polymerization of the six-membered cyclic carbonate monomer 2-allyloxymethyl-2-ethyltrimethylene carbonate, were used to prepare non-polyether polymer electrolytes. UV-crosslinking of the allyl side groups provided mechanically stable electrolytes with improved molecular flexibility-T g below 220 8C-and higher ionic conductivity-up to 4.3 3 10 27 S/ cm at 25 8C and 5.2 3 10 26 S/cm at 60 8C-due to the plasticizing properties of the allyl ether side groups. The electrolyte function was additionally demonstrated in thin-film Li battery cells.

Rechargeable Lithium Metal Batteries with an In‐Built Solid‐State Polymer Electrolyte and a High Voltage/Loading Ni‐Rich Layered Cathode

“…However, multiple difficult challenges remain including the large thermodynamic driving force for macromolecular stacking and crystallization, which generally yields low ambient‐temperature ionic conductivity; and the difficulty in infiltrating the highly viscous molten polymers into the nano‐sized pores of intercalating cathodes, especially when high‐loading materials are utilized for enhanced energy density 11–15. Furthermore, the most widely studied polymer electrolytes such as poly(ethylene oxide) (PEO) that afford acceptable conductivity and are compatible with alkali metal anodes, have limited oxidative stability at state‐of‐the‐art nickel‐rich transition metal cathodes, which limits their utility 16–23. Besides, polymer electrolytes require high‐concentration Li salts composed of large anions, most notably lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium bis(fluorosulfonyl) imide (LiFSI), to achieve sufficient amounts of dissociated ion pairs for efficient ion transport at room temperature 6,24,25.…”

Viscoelastic properties of poly(methyl methacrylate) with high glass transition temperature by lithium salt addition

“…Motomatsu et al studied the ion‐dipole interaction using poly(ethylene carbonate) containing a lithium salt by dielectric relaxation behaviors recently . Dynamic mechanical properties and thermal properties in the solid state and the ion‐dipole interaction for solid polymer electrolytes were reported by several researchers . However, the rheological properties in the molten state were not clarified.…”

“…21 Dynamic mechanical properties and thermal properties in the solid state and the ion-dipole interaction for solid polymer electrolytes were reported by several researchers. [22][23][24][25][26] However, the rheological properties in the molten state were not clarified.…”

Postpolymerization Modifications of Alkene‐Functional Polycarbonates for the Development of Advanced Materials Biomaterials

“…Crucially, the PAOMEC‐based electrolytes displayed an improved ionic conductivity (relative to PTMC‐based systems) of up to an order of magnitude at low temperatures, with this improved performance attributed to the plasticizing effect of the pendent allyl ether side groups. The authors also assembled functional thin‐film batteries using a Li metal anode and a V 2 O 5 cathode with the polymer as the electrolyte, confirming the ability of crosslinked PAOMEC to shuttle Li + between the electrodes …”

“…The authors also assembled functional thin-film batteries using a Li metal anode and a V 2 O 5 cathode with the polymer as the electrolyte, confirming the ability of crosslinked PAOMEC to shuttle Li + between the electrodes. [93]…”