Lewis-acid fillers direct lithium-ion transport in solid polymer electrolytes
Journal
Journal of Energy Storage
Journal Volume
181
ISSN
2352-152X
Date Issued
2026-12
Author(s)
Abstract
Regulating polymer–ion coordination is critical for overcoming the trade-off between ionic conductivity and oxidative stability in PEO-based solid polymer electrolytes. Herein, a dual Lewis-acid coordination strategy is developed by incorporating Al3+ and Ca2+ additives into a PEO–LiTFSI matrix to reconstruct the local ionic microenvironment. Spectroscopic analyses reveal reduced PEO crystallinity and weakened Li+–TFSI− association, while computational results suggest a lower Li+ migration barrier and a more homogeneous electrostatic field after AlCa coordination. The optimized PEO–LiTFSI–10AlCa electrolyte delivers an ionic conductivity of 3.44 × 10−4 S cm−1 at 50 °C, an electrochemical stability window of 5.4 V, and a Li+ transference number of 0.53. The electrolyte also enables stable Li plating/stripping for 1000 h and increases the critical current density to 1.1 mA cm−2. In Li|CPE|LFP asymmetric cells, the electrolyte enables an initial discharge capacity of 153.9 mAh g−1 with 88.9% retention after 100 cycles and approximately 99% Coulombic efficiency. XPS analysis further indicates the formation of a LiF-rich interphase containing AlF and CaF species. This work demonstrates that dual Lewis-acid coordination is an effective route to balance Li+ transport, oxidative stability, and interfacial robustness in PEO-based solid polymer electrolytes.
Subjects
All-solid-state batteries
Composite polymer electrolyte
Lewis-acid coordination
Molecular dynamics
PEO electrolyte
Publisher
Elsevier BV
Type
journal article