Abstract
Solid polymer electrolytes are promising in fulfilling the requirements for a stable lithium metal anode toward higher energy and power densities. In this work, we investigate the segmental dynamics, ionic conductivity, and crystallinity of a polymer electrolyte consisting of poly(ethylene oxide) (PEO) and lithium triflate salt, in the semi-crystalline state. Using quasi-elastic neutron scattering, the segmental dynamics of PEO chains confined between the crystalline lamellae is quantified, using Cole–Cole analysis. We show that the structural relaxation time, τ0, of PEO equilibrated near room temperature is six-fold longer than the same sample that had just cooled down to room temperature. This corresponds to a three-fold smaller ionic conductivity in the equilibrated condition. This work reveals that the segmental dynamics of semi-crystalline polymer electrolytes is very sensitive to thermal history. We demonstrate that quasi-elastic neutron scattering can be used to characterize the ion transport and segmental dynamics in the semi-crystalline state.
Original language | English |
---|---|
Article number | 592604 |
Journal | Frontiers in Chemistry |
Volume | 8 |
DOIs | |
State | Published - Jan 13 2021 |
Funding
This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering (XC, RS, and ND). Work at ORNL’s Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for U.S. DOE under contract no. DEAC05-00OR22725. Access to the HFBS was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Institute of Standards and Technology and the National Science Foundation under Agreement No. DMR-1508249. DSC experiments were conducted at ORNL’s Center for Nanophase Materials Sciences, which is a DOE Office of Science user facility. The identification of any commercial product or trade name does not imply endorsement or recommendation by the National Institute of Standards and Technology (NIST). This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering (XC, RS, and ND). Work at ORNL's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for U.S. DOE under contract no. DEAC05-00OR22725. Access to the HFBS was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Institute of Standards and Technology and the National Science Foundation under Agreement No. DMR-1508249. DSC experiments were conducted at ORNL's Center for Nanophase Materials Sciences, which is a DOE Office of Science user facility. The identification of any commercial product or trade name does not imply endorsement or recommendation by the National Institute of Standards and Technology (NIST).
Keywords
- crystallinilty
- ion transport
- polymer electrolyte
- quasi-elastic neutron scattering (QENS)
- segmental dynamics
- small angle X-ray scattering (SAXS)
- thermal history