The power of architecture – cage-shaped PEO and its application as a polymer electrolyte

Abstract

Herein we report for the first time on the gram-scale synthesis of a four-arm cage-shaped poly(ethylene oxide) (PEO) and its pioneering application as polymer electrolyte. The well supressed crystallization by...

Styrene-Based Poly(ethylene oxide) Side-Chain Block Copolymers as Solid Polymer Electrolytes for High-Voltage Lithium-Metal Batteries

“…However, despite these important attributes and great achievements, PEO-based SPEs often suffer from high crystallinity, which results in low ionic conductivities below its melting point due to the fact that ion transport is only taking place in the amorphous regions. , Therefore, to improve the ionic conductivity at lower temperatures, different approaches can be used to render the material completely amorphous, such as cross-linking, the implementation of plasticizers , or nanofillers, or blending with other polymers . Furthermore, approaches to alter the molecular architecture, such as side-chain or cage architectures, are successfully reducing crystallization to a significant amount, as we and others could demonstrate. − …”

Cage‐Shaped Polymers Synthesis: A Comprehensive State‐of‐the‐Art

“…In this sense, a first milestone to future applications was reached recently by synthesis of four‐arm cage‐shaped PEG in a single semi‐batch process with 43% yield at the gram‐scale (Table 4, Entry 19). [ 25 ] Taking advantage from the reduction of crystallinity in the cage PEG structure, its application as polymer electrolyte in lithium batteries was investigated.…”

“…In line with this statement, a new intramolecular strategy to obtain polymer cages was recently proposed by our research group (Table 4, Entries 18 and 19 and Scheme 5,VI). [24,25] Starting from alkyne-azide end-bifunctionalized symmetric four-arm 𝜖-PCL stars, the topological conversion was intramolecularly achieved by CuAAC tetramerization of the four end-groups into a thermodynamically favored D 4h - [3 4 ]triazolophane macrocycle, resulting in isolated yields between 36% and 78% depending on their molecular size. While this strategy is currently restricted to four-arm cage synthesis and therefore lacks the versatility of the previously mentioned ROMO approach, its real strength arises from its capacity to be easily upscaled with acceptable yields and precursor accessibility on the gram scale and in a semi-batch process.…”

Advanced Block Copolymer Design for Polymer Electrolytes: Prospects of Microphase Separation

“…Besides the usual listed advantages of PEO such as a low glass transition temperature ( T g ), chain flexibility, remarkable electrochemical stability against lithium metal, and great solubility for conductive lithium salts, it is readily available and straightforward to use due to its film forming ability . However, the provided ionic conductivity (especially at room temperature) often does not meet the high demands of industrial applications, so several approaches have been introduced to increase the ionic conductivity, e.g., by invoking nanofillers, blending with other polymers, implementing plasticizers, or polymer architectural approaches. , …”

“…10 However, the provided ionic conductivity (especially at room temperature) often does not meet the high demands of industrial applications, so several approaches have been introduced to increase the ionic conductivity, e.g., by invoking nanofillers, 11 blending with other polymers, 12 implementing plasticizers, 13 or polymer architectural approaches. 14,15 Though these approaches readily increased the ionic conductivity, polymer/battery chemists face a dilemma regarding the relationship of ionic conductivity and mechanical stability, since generally a higher ionic conductivity is achieved by lowering the T g , yielding a reduced mechanical stability. 16,17 Conversely, a higher T g increases the mechanical stability but decreases the ionic conductivity.…”