Anisotropic Lithium Ion Conductivity in Single-Ion Diblock Copolymer Electrolyte Thin Films

Macromol Rapid Commun. 2016 Feb;37(3):221-6. doi: 10.1002/marc.201500562. Epub 2015 Nov 30.

Abstract

Well-defined single-ion diblock copolymers consisting of a Li-ion conductive poly(styrenesulfonyllithium(trifluoromethylsulfonyl)imide) (PSLiTFSI) block associated with a glassy polystyrene (PS) block have been synthesized via reversible addition fragmentation chain transfer polymerization. Conductivity anisotropy ratio up to 1000 has been achieved from PS-b-PSLiTFSI thin films by comparing Li-ion conductivities of out-of-plane (aligned) and in-plane (antialigned) cylinder morphologies at 40 °C. Blending of PS-b-PSLiTFSI thin films with poly(ethylene oxide) homopolymer (hPEO) enables a substantial improvement of Li-ion transport within aligned cylindrical domains, since hPEO, preferentially located in PSLiTFSI domains, is an excellent lithium-solvating material. Results are also compared with unblended and blended PSLiTFSI homopolymer (hPSLiTFSI) homologues, which reveals that ionic conductivity is improved when thin films are nanostructured.

Keywords: RAFT polymerization; thin films; block copolymers; ionic conductivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anisotropy
  • Chromatography, Gel
  • Electric Conductivity*
  • Electrolytes / chemistry*
  • Ions
  • Lithium / chemistry*
  • Microscopy, Atomic Force
  • Polymers / chemistry*
  • Proton Magnetic Resonance Spectroscopy
  • Solvents / chemistry
  • Temperature

Substances

  • Electrolytes
  • Ions
  • Polymers
  • Solvents
  • Lithium