Entropic Penalty Switches Li + Solvation Site Formation and Transport Mechanisms in Mixed Polarity Copolymer Electrolytes
Year: 2023
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Emerging solid polymer electrolyte (SPE) designs for efficient Li-ion (Li + ) conduction have relied on polarity and mobility contrast to improve conductivity. To further develop this concept, we employ simulations to examine Li + solvation and transport in poly(oligo ethylene methacrylate) (POEM) and its copolymers with poly(glycerol carbonate methacrylate) (PGCMA). We find that Li + is solvated by ether oxygens instead of the highly polar PGCMA, due to lower entropic penalties. The presence of PGCMA promotes single-chain solvation, thereby suppressing interchain Li + hopping. The conductivity difference between random copolymer PGCMA- r -POEM and block copolymer PGCMA- b -POEM is explained in terms of a hybrid solvation site mechanism. With diffuse microscopic interfaces between domains, PGCMA near the POEM contributes to Li + transport by forming hybrid solvation sites. The formation of such sites is hindered when PGCMA is locally concentrated. These findings help explain how thermodynamic driving forces govern Li + solvation and transport in mixed SPEs.
Source: Macromolecules
Institutions: University of Chicago, Argonne National Laboratory
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $5,000
OpenAlex ID: W4386952800