Lithium Ion Pathway within Li7 La3 Zr2 O12 -Polyethylene Oxide Composite Electrolytes.
Polymer-ceramic composite electrolytes are emerging as a promising solution to deliver high ionic conductivity, optimal mechanical properties, and good safety for developing high-performance all-solid-state rechargeable batteries. Composite electrolytes have been prepared with cubic-phase Li7 La3 Zr2 O12 (LLZO) garnet and polyethylene oxide (PEO) and employed in symmetric lithium battery cells. By combining selective isotope labeling and high-resolution solid-state Li NMR, we are able to track Li ion pathways within LLZO-PEO composite electrolytes by monitoring the replacement of (7) Li in the composite electrolyte by (6) Li from the (6) Li metal electrodes during battery cycling. We have provided the first experimental evidence to show that Li ions favor the pathway through the LLZO ceramic phase instead of the PEO-LLZO interface or PEO. This approach can be widely applied to study ion pathways in ionic conductors and to provide useful insights for developing composite materials for energy storage and harvesting.
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA.
Jin
J
Zheng
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA.
Mingxue
0000-0002-7282-4100
M
Tang
Center of Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, FL, 32310, USA. hu@chem.fsu.edu.|Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA. hu@chem.fsu.edu.
Yan-Yan
0000-0003-0677-5897
YY
Hu
6,7Li NMR; diffusion pathways; isotope labeling; lithium ion batteries; solid-state electrolytes