A Super‐Ionic Solid‐State Block Copolymer Electrolyte

Small, vol. 20, pp. e2404297

Abstract

Abstract Polymer solid‐state electrolytes offer great promise for battery materials with high energy density, mechanical stability, and improved safety. However, their low ion conductivities have so far limited their potential applications. Here, it is shown for poly(ethylene oxide) block copolymers that the super‐stoichiometric addition of lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) as lithium salt leads to the formation of a crystalline PEO block copolymer phase with exceptionally high ion conductivities and low activation energies. The addition of LiTFSI further induces block copolymer phase transitions into bi‐continuous Fddd and gyroid network morphologies, providing continuous 3D conduction pathways. Both effects lead to solid‐state block copolymer electrolyte membranes with ion conductivities of up to 1·10 −1 S cm −1 at 90 °C, decreasing only moderately to 4·10 −2 S cm −1 at room temperature, and to >1·10 −3 S cm −1 at −20 °C, corresponding to activation energies as low as 0.19 eV. The co‐crystallization of PEO and LiTFSI with ether and carbonate solvents is observed to play a key role to realize a super‐ionic conduction mechanism. The discovery of PEO super‐ionic conductivity at high lithium concentrations opens a new pathway for fabrication of solid polymer electrolyte membranes with sufficiently high ion conductivities over a broad temperature range with widespread applications in electrical devices.

Authors 13

1. Daniel T. Krause

   Forschungszentrum Jülich · Helmholtz-Institute Münster

   Affiliation as printed

   Helmholtz Institute Münster IEK‐12 Forschungszentrum Jülich GmbH Corrensstr. 46 Münster Germany

2. Beate Förster

   Forschungszentrum Jülich · Ernst Ruska Centre

   Affiliation as printed

   Ernst Ruska‐Centre for Microscopy and Spectroscopy with Electrons Physics of Nanoscale Systems (ER‐C‐1) Forschungszentrum Jülich Wilhelm‐Johnen‐Straße Jülich Germany

3. Martin Dulle

   Forschungszentrum Jülich

   Affiliation as printed

   Jülich Centre for Neutron Science (JCNS‐1) Forschungszentrum Jülich Wilhelm‐Johnen‐Straße Jülich Germany

4. Susanna Krämer

   Forschungszentrum Jülich · Helmholtz-Institute Münster

   Affiliation as printed

   Helmholtz Institute Münster IEK‐12 Forschungszentrum Jülich GmbH Corrensstr. 46 Münster Germany

   Jülich Centre for Neutron Science (JCNS‐1) Forschungszentrum Jülich Wilhelm‐Johnen‐Straße Jülich Germany

5. Steffen Böckmann

   University of Münster

   Affiliation as printed

   Institute of Physical Chemistry University of Münster Corrensstr. 28/30 Münster Germany

6. Caroline Mönich

   University of Münster

   Affiliation as printed

   Institute of Physical Chemistry University of Münster Corrensstr. 28/30 Münster Germany

7. Michael Ryan Hansen

   University of Münster

   Affiliation as printed

   Institute of Physical Chemistry University of Münster Corrensstr. 28/30 Münster Germany

8. Monika Schönhoff

   University of Münster

   Affiliation as printed

   Institute of Physical Chemistry University of Münster Corrensstr. 28/30 Münster Germany

9. Vassilios Siozios

   University of Münster

   Affiliation as printed

   MEET Battery Research Center University of Münster Corrensstr. 46 Münster Germany

10. Mariano Grünebaum

    Forschungszentrum Jülich · Helmholtz-Institute Münster

    Affiliation as printed

    Helmholtz Institute Münster IEK‐12 Forschungszentrum Jülich GmbH Corrensstr. 46 Münster Germany

11. Martin Winter

    Forschungszentrum Jülich · University of Münster · Helmholtz-Institute Münster

    Affiliation as printed

    Helmholtz Institute Münster IEK‐12 Forschungszentrum Jülich GmbH Corrensstr. 46 Münster Germany

    MEET Battery Research Center University of Münster Corrensstr. 46 Münster Germany

12. Stephan Förster corresponding Aachen Institute of Physical Chemistry

    RWTH Aachen University

    Affiliation as printed

    Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 Aachen Germany

13. Hans‐Dieter Wiemhöfer corresponding

    Forschungszentrum Jülich · University of Münster · Helmholtz-Institute Münster

    Affiliation as printed

    Helmholtz Institute Münster IEK‐12 Forschungszentrum Jülich GmbH Corrensstr. 46 Münster Germany

    MEET Battery Research Center University of Münster Corrensstr. 46 Münster Germany