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Controlling mixed Li/electronic conduction in conjugated polymeric ionic liquids through the addition of ionic and electronic dopants

POSTER

Abstract

Conjugated polymeric ionic liquids (conjugated PILs) may be useful in electrochemical applications, owing to their potential for simultaneous ionic and electronic conductivity. The addition of ionic and electronic dopants is essential to control the mixed conductivity, although the doping design rules remain largely unknown. Here, we investigate the roles of LiBF4 as an ionic dopant and NOBF4 as an electronic dopant on the overall mixed conduction of a model conjugated PIL, P3HT(Im+)BF4-. The thiophene backbone is selected to allow hole conduction while the ionic (Im+)BF4- sidechain solvates mobile ions. The addition of either the ionic dopant LiBF4 or the electronic dopant NOBF4 leads to a simultaneous increase in the mixed conductivity. Improvements in ionic conduction by LiBF4 and NOBF4 can be interpreted as a result of plasticization and increased mobile ion density respectively. The enhanced electronic conductivity is thought to proceed from oxidative or Lewis acid doping of the polymer backbone by NOBF4 or LiBF4 respectively. Molecular dynamics simulation will reveal the role of LiBF4 to enhanced electronic conductivity. This study offers a new insight on the impact of ionic and electronic dopants on mixed conduction and future optimization of conjugated PILs.

Presenters

  • Dakota Rawlings

    University of California, Santa Barbara

Authors

  • Dongwook Lee

    University of California, Santa Barbara

  • Dakota Rawlings

    University of California, Santa Barbara

  • Ioan-Bogdan Magdau

    California Institute of Technology

  • Elayne Thomas

    University of California, Santa Barbara

  • Thomas Miller

    Division of Chemistry and Chemical Engineering, Caltech, California Institute of Technology

  • Ram Seshadri

    University of California, Santa Barbara, Materials Department and Materials Research Laboratory, University of California, Materials Research Laboratory and Materials Department, University of California, Santa Barbara

  • Rachel A Segalman

    University of California, Santa Barbara, Chemical Engineering, University of California, Santa Barbara, University of California at Santa Barbara