Phase Behavior of Hybrid Inorganic-Organic Diblock Copolymer Electrolytes

ORAL

Abstract

Solid polymer electrolytes are advantageous for applications in lithium batteries due to improved chemical stability compared to organic liquid electrolytes. Diblock copolymer electrolytes offer highly tunable nanostructures with both soft, ion-conducting domains and mechanically rigid non-conducting domains. The phase behavior of poly(ethylene oxide) -block-polyhedral oligomeric silsesquioxane acrylate (PEO-POSS) mixed with lithium bis(trifluoromethane)sulfonimide (LiTFSI) salt is studied by varying the diblock composition and salt concentration. Using small angle X-ray scattering (SAXS), the morphology and Flory-Huggins interaction parameter is obtained to quantify the thermodynamic interactions. PEO-POSS without salt exhibits a classical order-to-disorder transition. Adding salt dramatically changes the phase behavior and a disorder-to-order transition is observed upon heating. Upon further salt addition, a transition from lamellae to coexisting lamellae and hexagonally packed cylinders is observed. Our results suggest that the addition of salt plays a more complicated role in this hybrid organic/inorganic electrolytes in comparison to traditional all organic diblock copolymer electrolytes.

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Presenters

  • Gurmukh Sethi

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

Authors

  • Gurmukh Sethi

    Materials Science and Engineering, University of California, Berkeley, 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