Elimination of “Voltage Noise” of Poly (Ethylene Oxide)-Based Solid Electrolytes in High-Voltage Lithium Batteries: Linear versus Network Polymers

iScience

Johannes Kasnatscheew¹  Gerrit Homann²  Martin Winter²  Lukas Stolz² 

[1] MEET Battery Research Center, Institute of Physical Chemistry, University of Münster, Corrensstraße 46, 48149 Münster, Germany;Helmholtz-Institute Münster, IEK-12, Forschungszentrum Jülich GmbH, Corrensstraße 46, 48149 Münster, Germany;

关键词: Polymer Chemistry;    Electrochemistry;    Electrochemical Energy Storage;   

DOI  :  

来源: DOAJ

【 摘 要 】

Summary: Frequently, poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) reveal a failure with high-voltage electrodes, e.g. LiNi0.6Mn0.2Co0.2O2 in lithium metal batteries, which can be monitored as an arbitrary appearance of a “voltage noise” during charge and can be attributed to Li dendrite-induced cell micro short circuits. This failure behavior disappears when incorporating linear PEO-based SPE in a semi-interpenetrating network (s-IPN) and even enables an adequate charge/discharge cycling performance at 40°C. An impact of any electrolyte oxidation reactions on the performance difference can be excluded, as both SPEs reveal similar (high) bulk oxidation onset potentials of ≈4.6 V versus Li|Li+. Instead, improved mechanical properties of the SPE, as revealed by compression tests, are assumed to be determining, as they mechanically better withstand Li dendrite penetration and better maintain the distance of the two electrodes, both rendering cell shorts less likely.

【 授权许可】

Unknown