Novel Alternating Comblike Copolymer Electrolytes with Single Lithium Ionic Conduction

Abstract

Poly[lithium-N-(4-sulfophenyl)maleimide-co-methoxyoligo(oxyethylene)methacrylate], P(LiS-MOE n ), with three different oligo(oxyethylene) side chains (i.e., three different n values) have been synthesized. The copolymers are of a new type of comblike, nearly alternating copolymer electrolytes, showing single lithium ionic conductivity. All the three copolymers show a glass transition at about -50 °C (T g1 ). In addition, copolymers with n ) 7 and 12 also exhibit a second glass transition in the temperature range of 30-50 °C (T g2 ), while the copolymer with n ) 16 shows an endothermic peak near room temperature. T g1 is assigned to the oligo(oxyethylene) side chain, while T g2 is attributed to the main chain of the copolymer domain. The melting point (T m ) is attributed to the endothermic change of the partially crystalline phase formed by the long oligoether side chain. When the temperature is below 50 °C, P(LiSMOE n )s with larger n values have a higher ionic conductivity. When the temperature is above 50 °C, however, P(LiSMOE n )s with smaller n values show higher ionic conductivity because of their higher salt concentration. The maximum ionic conductivity at 30 °C is 1.5 × 10 -7 S cm -1 for n ) 16. The temperature dependence of ionic conductivity indicates that the Arrhenius behavior is not obeyed. The ionic conduction follows a special dual Vogel-Tamman-Fulcher (VTF) behavior.

A Single-Ion Conducting UiO-66 Metal–Organic Framework Electrolyte for All-Solid-State Lithium Batteries

“…The conductivity of UiO-66-LiSS was 3 orders of magnitude higher than that of the −C 6 H 5 SO 3 Li-based blend polymer (3.0 × 10 −8 S/cm at 25 °C) 40 and 2 orders of magnitude higher than that of the −C 6 H 5 SO 3 Li-based random copolymer (1.5 × 10 −7 S/cm at 30 °C). 41 Compared to the UiO-66-LiSS, the conductivity of the UiO-66-Br matrix was too low to be measured accurately.…”

Poly(ethylene oxide)-based electrolytes for lithium-ion batteries

“…592 Since then, many researchers prepared single-ion conductors based on copolymers with POEM or poly(oligo-oxyethylene acrylate) (POEA) as a block. These copolymers include poly(oligo-oxyethylene methacrylate-co-lithium acrylamidocaproate) (P(OEM-AACLi)), 593 poly(lithium-N-(4-sulfophenyl)maleimide-co-methoxyoligo(oxyethylene)methacrylate) (P(LiSMOE n )), 594 poly(lauryl methacrylate)-b-poly(lithium methacrylate)-b-poly((oxyethylene) 9 methacrylate) (PLMA-b-PLiMA-b-POEM), 595 poly(OEA-co-lithium 1,1,2-triuorobutane sulfonate acrylate), (P(OEA-co-TFBSALi)), 596 (P(OEA-co-OEASLi)), 597 and P(STFSILi-co-OEA). 598 Interestingly, single-ion conductors based on the polyphosphazene backbone (PNEO-PNTFSILi), 599 polysiloxane backbone (PSiTFSA-Li and PSiSu-Li), [458][459][460] organoboron polymer backbone (PBSILi), 600 borate polymer backbone (PBEOLi), 47,601 polyphenolate backbone (PPEOLi), 602 and poly(p-phenylene) backbone (PPEOSLi) 603 were also investigated for electrolyte systems.…”

Promising Routes to a High Li+ Transference Number Electrolyte for Lithium Ion Batteries

“…Improved conductivity in dry SIC polymers, however, has proven elusive, particularly at room temperature. To illustrate this point, Figure summarizes the conductivity of 34 individual SIC polymer chemistries, based on the date of publication, at both 30 and 90 °C. ,,,,,− Several example high conductivity polymers are shown, with all having the common feature of PEO incorporated as a component of the backbone or as a side chain; the [EO]/[Li] ratio is shown to identify the polymer within the reference. Generally, the highest conductivity polymer from each reference is shown.…”