Sustainable Design of Recyclable Solid-State Batteries of Sulfide Electrolyte

In recent decades, the development of solid electrolytes including sulfide, halide, polymer, and oxide for solid-state batteries has made significant progress. Materials with high ionic conductivities of more than 10-3 S cm-1 have become commercially available [1]. In particular, sulfide (Li6PS5X; X=Cl, Br, I) electrolytes are promising candidates for solid-state batteries because of their low densities, processability and low-cost precursors. However, to achieve good contact between the electrodes and solid electrolytes, high pressures have to be applied to ensure high performance and stable cycling of the battery cells. For industrially relevant battery cells, the solid electrolytes must be processed to form thin (~30 µm) electrolyte layers that are either applied directly to the electrodes as a coating or prepared as a stand-alone film. As a result, these electrolyte powders will need to be further processed for use in a battery cell. Methods and technologies closely related to those already used in conventional battery production are preferred. For this reason, the wet chemical processing of the sulfide electrolyte powders is a suitable approach in this respect [2]. Based on the two manufacturing processes of the solid-state battery, it is quite important and attractive to re-use the materials that are obtained from the solid-state battery. However, the understanding of the recyclability of SSBs as compared to LIBs is limited from the point of view of the possible adaptation of LIBs methods to the recycling technologies of solid-state batteries. Therefore, new strategies for indirect recycling of different types of SSBs need to be explored. These recycling approaches, which require robust, energy-efficient processes with reduced environmental impact, can provide a vision for high recycling rates and reuse of materials and components for lithium-ion and solid-state batteries (Figure 1).

Figure 1. Schematic illustration of principle approaches of the recycling process for solid-state batteries.

References
[1] A. Tron, H. Raad, N. Zhang, A. Paolella, P. Wulfert-Holzmann, V. Kolotygin, P. López-Aranguren, A. Beutl, J. Energy Storage 2023, 66, 107480.
[2] A. Tron, R. Hamid, N. Zhang, A. Beutl, Nanomaterials 2023, 13 (2), 327.

Acknowledgements. This work was supported by the European Commission through the H2020 program under grant agreement No. 875028 (SUBLIME project) and the Horizon Europe program for research and innovation under grant agreement No. 101069686 (PULSELION project).