The effect of chemical structure on the morphology, ion transport, and modulus of hybrid inorganic-organic diblock copolymer electrolytes

ORAL

Abstract

Poly(ethylene oxide)-b-polyhedral oligomeric silsequioxane (PEO-POSS) mixed with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt is a nanostructured hybrid organic-inorganic diblock copolymer electrolyte that may enable lithium metal batteries. The organic poly(ethylene oxide) block solvates lithium ions and facilitates ion transport while the inorganic polyhedral oligomeric silsequioxane (POSS) block provides mechanical rigidity, decoupling typically antagonistic mechanical and ion conducting properties. PEO-POSS with different alkyl chain substituents on the POSS monomer’s silica cage were synthesized to study the effect of chemical structure on morphology, ion transport, and modulus. Ionic conductivity, salt diffusion coefficient, and steady-state cation transference number were measured for a range of salt concentrations. In general, increasing the alkyl chain length was found to promote ordering and increase mechanical stiffness, while decreasing ionic conductivity.

*This work was supported by a National Defense Science and Engineering Graduate Fellowship.

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Presenters

  • Kevin Gao

    • University of California, Berkeley

Authors

  • Kevin Gao

    • University of California, Berkeley

  • Gurmukh Sethi

    • Materials Science and Engineering, University of California, Berkeley
    • University of California, Berkeley

  • Saheli Chakraborty

    • University of California, Berkeley

  • Irune Villaluenga

    • University of California, Berkeley
    • Lawrence Berkeley National Laboratory

  • Nitash Balsara

    • Chemical and Biomolecular Engineering, University of California, Berkeley
    • University of California, Berkeley
    • The Department of Chemical & Biomolecular Engineering, University of California Berkeley