The Influence of Polyethylene Oxide Degradation in Polymer‐Based Electrolytes for NMC and Lithium Metal Batteries
A multilayered ternary solid polymer electrolyte (TSPE) is presented. First, the influence of polyethylene oxide degradation on cell failure, development of subsequent volatile degradation products, and cell impedance is analyzed. The low electrochemical stability window/oxidative stability (≥3.8 V)...
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Published in | Advanced energy and sustainability research Vol. 4; no. 12 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Argonne
John Wiley & Sons, Inc
01.12.2023
Wiley-VCH |
Subjects | |
Online Access | Get full text |
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Summary: | A multilayered ternary solid polymer electrolyte (TSPE) is presented. First, the influence of polyethylene oxide degradation on cell failure, development of subsequent volatile degradation products, and cell impedance is analyzed. The low electrochemical stability window/oxidative stability (≥3.8 V) results in side‐chain oxidation and loss of active material. Subsequently, electrolyte stability is improved and a thin‐film (≤50 μm) TSPE with three functional layers is developed to match the wide‐ranging electrolyte requirements toward Li metal anodes and different cathode materials like LiNi0.6Mn0.2Co0.2O2 and LiFePO4 (NCM622, LFP). The high‐voltage stability of ≥4.75 V makes the TSPE a promising candidate in high‐voltage applications. Because of high Coulombic efficiencies in NMC622‖Li metal (99.7%) and LFP‖Li metal (99.9%) cells, the presented electrolyte enables stable long‐term cycling with great capacity retention of 86% and 94%, respectively. The temperature stability of >300 °C and the capability to prevent high surface area Li and dendrite formation (even at an areal capacity utilization of >40 mAh cm−2) contribute to high safety under a wide range of conditions.
Polyethylene oxide is the most researched solid polymer electrolyte. However, it is unsuitable for lithium metal and NMC batteries due to its low electrochemical stability, resulting in degradation and shortened battery life. Therefore, a protective poly(vinylidene fluoride‐co‐hexafluoropropylene) layer is used to prevent electrolyte degradation. |
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ISSN: | 2699-9412 2699-9412 |
DOI: | 10.1002/aesr.202300153 |