Reviving Reused Solid State Lithium Metal Battery Cells

Researchers in the United States have been focusing on enhancing the recyclability and reusability of solid-state battery cells. The team at Penn State University has made significant strides in this area by reconfiguring the design of solid-state battery cells with lithium metal anodes and LTO cathodes. Their goal was to ensure that all components of the battery can be easily recycled and reused in the creation of new cells.

Traditionally, the recycling of batteries has been challenging as core components tend to mix during the process, forming a problematic "black mass" that contains valuable materials required for batteries. This issue is further complicated in solid-state batteries due to the presence of solid electrolytes, which also get intermixed with the black mass. To address this, researchers inserted polymer layers at specific interfaces within the battery cell to facilitate the separation of components during recycling.

Prof Enrique Gomez, from the Penn State College of Engineering, emphasized the importance of considering the end-of-life implications of rechargeable batteries. He highlighted the potential of their work in showcasing the possibilities of recycling solid-state batteries through strategic design elements. Doctoral student Yi-Chen Lan explained the significance of dissolving the polymer layer during recycling to enable the easy separation of electrode and electrolyte components.

Through the use of cold sintering, a technique developed in 2016 at Penn State, the researchers successfully combined recovered metals and electrodes to create a composite material. This innovative approach allowed for the reconstruction of the battery with the addition of polymer layers, enabling the recycling of the entire battery for further use. The reconstructed battery demonstrated an impressive discharge capacity of between 92.5% and 93.8% of its original performance.

Looking ahead, the team envisions applying these advancements to larger batteries used in devices like cell phones and laptops as solid-state battery technology becomes more prevalent. While the commercialization of all-solid-state lithium batteries is still evolving, the insights gained from this research offer valuable ideas for designing recyclable versions of these batteries, paving the way for a more sustainable approach to battery technology.