Polysilaketals: High‐Performance Polyether‐Based Electrolytes with Tunable Disubstituted Silane Linkers

Journal Article · Fri Jan 10 00:00:00 EST 2025 · Angewandte Chemie International Edition

DOI:https://doi.org/10.1002/anie.202415069· OSTI ID:2584834

Rugh, Haley J; Lee, Jaeyong; Sun, Chenyue; Abdo, Emily E; N., Juliana; Balsara, Nitash P; Coates, Geoffrey W

Polymer electrolytes exhibit higher energy density and improved safety in lithium-ion batteries relative to traditionally used liquid electrolytes but are currently limited by their lower electrochemical performance. Aiming to access polymer electrolytes with competitive electrochemical properties, we developed the anionic ring-opening polymerization (AROP) of cyclic silaketals to synthesize amorphous silicon-containing polyether-based electrolytes with varying substituent bulk of the general formula [OSi(R)2(CH2CH2O)2]n (R=alkyl, phenyl). As opposed to previously reported uncontrolled polycondensation routes toward low molecular weight polysilaketals, AROP allows access to targeted molecular weights above the entanglement threshold of the polymers. The polysilaketal with the lowest steric bulk (P(OSiMe,Me-2EO)) exceeds the conductivity of poly(ethylene oxide) (PEO), a leading polymer electrolyte. To the best of our knowledge, this is the first solid polymer electrolyte to achieve this benchmark. Steric bulk in polysilaketals was found to impart stability and two bulkier polysilaketals, P(OSiEt,Et-2EO) and P(OSiMe,Ph-2EO), exhibited higher current fractions than PEO over a wide range of salt loadings. Moreover, the efficacy of P(OSiEt,Et-2EO) was competitive with that of PEO. Taken together, the tunable and competitive electrochemical properties of polysilaketals validate the systematic incorporation of silyl groups as a strategy to access high performance polymer electrolytes.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: US Department of Energy; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Materials Sciences & Engineering Division (SC-22.2)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 2584834
• Journal Information: Angewandte Chemie International Edition, Journal Name: Angewandte Chemie International Edition Journal Issue: 2 Vol. 64
• Country of Publication: United States
• Language: English