Nanosecond solvation dynamics in a polymer electrolyte for lithium batteries

Neel J Shah; Chao Fang; Naresh C Osti; Eugene Mamontov; Xiaopeng Yu; Jaeyong Lee; Hiroshi Watanabe; Rui Wang; Nitash P Balsara

doi:10.1038/s41563-024-01834-y

Nanosecond solvation dynamics in a polymer electrolyte for lithium batteries

Nat Mater. 2024 May;23(5):664-669. doi: 10.1038/s41563-024-01834-y. Epub 2024 Feb 27.

Authors

Neel J Shah^#^{1

2}, Chao Fang^#^{1

2}, Naresh C Osti³, Eugene Mamontov³, Xiaopeng Yu², Jaeyong Lee², Hiroshi Watanabe⁴, Rui Wang^{5

6}, Nitash P Balsara^{7

8}

Affiliations

¹ Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA.
² Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
³ Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
⁴ Institute for Chemical Research, Kyoto University, Uji, Japan.
⁵ Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA. ruiwang325@berkeley.edu.
⁶ Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. ruiwang325@berkeley.edu.
⁷ Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA. nbalsara@berkeley.edu.
⁸ Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. nbalsara@berkeley.edu.

^# Contributed equally.

PMID: 38413811
DOI: 10.1038/s41563-024-01834-y

Abstract

Solvation dynamics critically affect charge transport. Spectroscopic experiments and computer simulations show that these dynamics in aqueous systems occur on a picosecond timescale. In the case of organic electrolytes, however, conflicting values ranging from 1 to several 100 picoseconds have been reported. We resolve this conflict by studying mixtures of an organic polymer and a lithium salt. Lithium ions coordinate with multiple polymer chains, resulting in temporary crosslinks. Relaxation of these crosslinks, detected by quasielastic neutron scattering, are directly related to solvation dynamics. Simulations reveal a broad spectrum of relaxation times. The average timescale for solvation dynamics in both experiment and simulation is one nanosecond. We present the direct measurement of ultraslow dynamics of solvation shell break-up in an electrolyte.

Grants and funding

DE-AC02-06CH11357/U.S. Department of Energy (DOE)