Journal
MATERIALS ADVANCES
Volume 2, Issue 10, Pages 3251-3256Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/d1ma00009h
Keywords
-
Categories
Funding
- German Federal Ministry for Education and Research within the project FestBatt [13XP0175A]
Ask authors/readers for more resources
Pure PEO-based solid polymer electrolyte is often considered unsuitable for high voltage applications in Li metal batteries due to destructive failure caused by short circuits during dendrite penetration. This failure can be prevented by increasing electrode distance or incorporating a spacer to enable stable operation and fulfill benchmark standards in systematic R&D.
Pure, i.e., linear poly(ethylene oxide)-based solid polymer electrolyte (PEO-based SPE) as a common benchmark system for Li metal batteries (LMBs) is frequently assumed to be unsuitable for high voltage applications e.g., with LiNi0.6Mn0.2Co0.2O2 (NMC622)-based cathodes. In fact, a destructive failure appears immediately after cell operation, seen by a random-like voltage noise during charge, rendering continuous charge/discharge cycling in e.g., NMC622||Li cells not possible. Counterintuitively, this failure is a result of short-circuits in the course of e.g., Li dendrite penetration. It is shown that the distance between the electrodes plays a crucial role. This failure is more likely with a lower distance, particularly when the SPE is mechanically prone to shrinkage, for example at higher temperatures as systematically revealed by mechanical compression tests. Additionally, the active mass loading has a crucial impact on short circuits, and thus the voltage noise failure, as well. An effective and practically simple solution to realize cell operation with a PEO-based SPE is the incorporation of a spacer between the electrodes. This modification prevents the detrimental shrinkage and enables charge/discharge cycling performance in NMC622||Li cells with a defined and constant electrode distance, thus without voltage noise, and finally fulfills a reasonable benchmark for systematic R&D with specific capacities above 150 mA h g(-1) even at 40 degrees C.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available