A research team at Helmholtz Center Berlin (HZB) has investigated lithium-sulfur pouch cells with reduced electrolyte content under realistic conditions for the first time. Operando neutron tomography revealed how the electrolyte distributes itself across the electrodes during charging and discharging processes. These experiments were conducted at the Institut Laue-Langevin in Grenoble, France, and allowed for a precise analysis of light elements, such as lithium and hydrogen. The cells were manufactured in the Pouch Cell Assembly Lab at HZB with industry-standard parameters. The goal was to understand the wetting processes crucial to the functionality and lifespan of lithium-sulfur batteries when the electrolyte amount is low.
Dynamic wetting behavior documented
The investigations revealed that unwet areas tend to accumulate locally, particularly at the start of rest phases. Longer rest periods led to only minor improvements in electrolyte distribution. In contrast, charging and discharging cycles increased the homogeneity of wetting, thereby activating the sulfur. For the first time, periodic changes in electrolyte behavior related to sulfur compound chemical reactions could be described. These results offer insight into the causes of accelerated aging processes and failures in lithium-sulfur systems. At the same time, the results are intended to support the development of compact cells with higher energy density. This project is funded by the German Federal Ministry of Research, Technology and Space through the “Battery 2020” program, as well as by the “HealingBat” EU Horizon project.
Source:
https://www.helmholtz-berlin.de/pubbin/news_seite?nid=30866&sprache=en&seitenid=74699
