Solid Polymer Electrolytes Based on Phosphonate and Cyclocarbonate Units for Safer Full Solid State Lithium Metal Batteries

Abstract

Solid-state polymer electrolytes are key components for future batteries with higher energy density as well as increased safety and processability. In this context, a solid polymer electrolyte is developed from statistical copolymers containing flame-retardant phosphonate units and ion-conductive cyclocarbonate moieties mixed with lithium salts. Ionic conductivity measured at room temperature for those copolymers (≈10 −5 S cm −1 ) are in the same range as typical solid polymeric electrolytes not based on poly(ethylene oxide). Moreover, those copolymers electrolytes are stable in a wide electrochemical window (0.5 -4.5 V vs Li + /Li) and at high temperature (>120 °C) and they lead to a better ionic conductivity than the corresponding homopolymer blends of a similar composition, which is explained by a better lithium salt solubility and better-defined ion-conduction pathways in case of the copolymer. Finally, it has demonstrated the possibility to have fire-retardant properties afforded by phosphonate groups in copolymers without impacting the ionic conductivity.

Extracting higher-conductivity designs for solid polymer electrolytes by quantum-inspired annealing

“…The carbonate polymer exhibited a room-temperature conductivity of 10 −5 S cm −1 with LiTFSI, about 10 times greater than the current electrolyte. 51 However, the loss in conductivity was slight compared with the drastic difference in glass transition temperatures of >150 °C for trithiocarbonate and −19 °C for carbonate.…”

“…The result was different from a carbonate polymer in which the sulfur atoms in PTCMA were replaced by oxygens, and the plasticizing effect lowered the glass transition temperature to −19 °C. 51 The weaker interactions of sulfur with lithium than with oxygen according to the HSAB rule may have resulted in the retention of the original mechanical properties. The carbonate polymer exhibited a room-temperature conductivity of 10 −5 S cm −1 with LiTFSI, about 10 times greater than the current electrolyte.…”

Phosphorus-Containing Polymer Electrolytes for Li Batteries

“…The homopolymerization of monomer dimethyl(methacryloyloxy)methyl phosphonate (MAPC1, 32) and monomer(2-Oxo-1,3-dioxolan-4-yl)methyl methacrylate (MA-CyCB, 31), allowed the obtaining of homopolymer poly(MAPC1), with an apparent Mn of 61 × 10 3 g mol −1 and a polydispersity of 1.9 and, respectively, of poly(MACyCB) with a molar mass of Mn of 67 × 10 3 g mol −1 and a polydispersity of 2.60 [29]. SPE membranes were prepared either from copolymer or a mix of homopolymers with the same ratio of both comonomers (MAPC1 and MACyCB) (Figure 9).…”

“…The SPE membranes based on the poly(MAPC1-r-MAcy CB) showed better LiTFSI solubilization in comparison with the analogous homopolymer-based SPEs. This will lead to obtaining a higher ionic conductivity, based on the polymer architecture [29].…”

A series of bifunctional metalloporphyrins as efficient catalysts for cycloaddition of CO2 with epoxides

“…For example, in industry, CO 2 is used as raw material to synthesize urea, 3 methanol, [4][5][6] polycarbonate, 7 and cyclic carbonate. 8,9 Among them, the 100% atom-economical cycloaddition reaction of CO 2 and epoxide to produce cyclic carbonate has the most promising development for the excellent market application value of cyclic carbonate in lithium batteries, 10 polymer materials, 11,12 fuel, 13 and other new energy fields. At present, various catalysts have been reported to have promoting effects on this cycloaddition reaction, such as quaternary ammonium salts, 14 metal complexes, 15 ionic liquids, [16][17][18][19] quaternary phosphonium salts, 20 amines, 21 metal oxides.…”