Improved interfacial li-ion transport in composite polymer electrolytes via surface modification of LLZO

Counihan, Michael J. [Argonne National Laboratory (ANL), Argonne, IL (United States)]; Lee, Jungkuk [Argonne National Laboratory (ANL), Argonne, IL (United States)]; Mirmira, Priyadarshini [Univ. of Chicago, IL (United States)]; Barai, Pallab [Argonne National Laboratory (ANL), Argonne, IL (United States)]; Burns, Meghan E. [Argonne National Laboratory (ANL), Argonne, IL (United States); Univ. of Chicago, IL (United States)]; Amanchukwu, Chibueze V. [Univ. of Chicago, IL (United States)]; Srinivasan, Venkat [Argonne National Laboratory (ANL), Argonne, IL (United States)]; Zhang, Yuepeng [Argonne National Laboratory (ANL), Argonne, IL (United States)]; Tepavcevic, Sanja [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000301518832)

doi:10.20517/energymater.2024.195

DOE OSTI · 2574955

Improved interfacial li-ion transport in composite polymer electrolytes via surface modification of LLZO

Counihan, Michael J. [Argonne National Laboratory (ANL), Argonne, IL (United States)]·Lee, Jungkuk [Argonne National Laboratory (ANL), Argonne, IL (United States)]·Mirmira, Priyadarshini [Univ. of Chicago, IL (United States)]·Barai, Pallab [Argonne National Laboratory (ANL), Argonne, IL (United States)]·Burns, Meghan E. [Argonne National Laboratory (ANL), Argonne, IL (United States); Univ. of Chicago, IL (United States)]·Amanchukwu, Chibueze V. [Univ. of Chicago, IL (United States)]·Srinivasan, Venkat [Argonne National Laboratory (ANL), Argonne, IL (United States)]·Zhang, Yuepeng [Argonne National Laboratory (ANL), Argonne, IL (United States)]·Tepavcevic, Sanja [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000301518832)

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Abstract

Composite polymer electrolytes that incorporate ceramic fillers in a polymer matrix offer mechanical strength and flexibility as solid electrolytes for lithium metal batteries. However, fast Li + transport between polymer and Li + -conductive filler phases is not a simple achievement due to high barriers for Li + exchange across the interphase. This study demonstrates how modification of Li 7 La 3 Zr 2 O 12 (LLZO) nanofiller surfaces with silane chemistries influences Li + transport at local and global electrolyte scales. Anhydrous reactions covalently link amine-functionalized silanes [(3-aminopropyl)triethoxysilane (APTES)] to LLZO nanoparticles, which protects LLZO in air. APTES functionalization lowers the poly (ethylene oxide) (PEO)-LLZO interphase resistance to half that of unmodified LLZO and increases effective Li + transference number, while insulating Al 2 O 3 completely blocks ion exchange and lowers transference number and conductivity in PEO-lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-LLZO composites. Modeling an inner resistive interphase between LLZO and PEO surrounded by an outer conductive interphase explains non-linear conductivity trends. Solid-state 7 Li & 6 Li nuclear magnetic resonance shows Li + only exchanges between PEO-LiTFSI and some LLZO interphase, with no appreciable Li + transport through bulk LLZO. Surface functionalization is a promising path toward lowering the polymer-ceramic interphase resistance. This work demonstrates that local changes in Li + transport affect macroscopic performance, highlighting the intricate relationships between all interfaces in inherently heterogeneous composite polymer electrolytes.

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25 ENERGY STORAGE Composite polymer electrolyte LLZO interface interphase ion transport lithium vacancies silane

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Counihan, Michael J. [Argonne National Laboratory (ANL), Argonne, IL (United States)], Lee, Jungkuk [Argonne National Laboratory (ANL), Argonne, IL (United States)], Mirmira, Priyadarshini [Univ. of Chicago, IL (United States)], Barai, Pallab [Argonne National Laboratory (ANL), Argonne, IL (United States)], Burns, Meghan E. [Argonne National Laboratory (ANL), Argonne, IL (United States); Univ. of Chicago, IL (United States)], Amanchukwu, Chibueze V. [Univ. of Chicago, IL (United States)], Srinivasan, Venkat [Argonne National Laboratory (ANL), Argonne, IL (United States)], Zhang, Yuepeng [Argonne National Laboratory (ANL), Argonne, IL (United States)], Tepavcevic, Sanja [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000301518832). 2025-01-22. Improved interfacial li-ion transport in composite polymer electrolytes via surface modification of LLZO. https://doi.org/10.20517/energymater.2024.195

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