Practical Upscaling of Coating and Drying Processes for Sulfide-Based Solid-State Battery Component Production

Sulfide-based solid-state batteries (SSBs) are emerging as one of the most promising successors to conventional lithium-ion batteries (LIBs) due to their enhanced energy and power density. Their components can be manufactured using adapted wet-processing techniques from conventional LIB electrode production. The coating and drying processes play a crucial role, directly influencing the mass loading and the cohesion and adhesion of the layers. While existing research primarily focuses on coating and drying at the lab scale, strategies for upscaling to a continuous roll-to-roll process remain unaddressed. This work aims to comprehend the key factors for transferring table-top coating and drying process parameters to a roll-to-roll fabrication process. Chlorine-rich argyrodite sulfide solid electrolyte was used to produce solid electrolyte separators and composite cathodes via doctor blade coating with table-top processing in an argon-filled glovebox. The standard table-top coating parameters were then applied to the roll-to-roll machinery, and the mass loading, porosity, and tensile strength of the produced components were compared. The results highlighted the different effect the mass loading has on the tensile strength of sulfide-based SSB components compared to conventional LIB electrodes as well as the impact forced convection has on the sulfide-based SSB components' tensile strength after drying. The roll-to-roll produced components showed improvements in the mass loading's homogeneity and revealed new defect sources absent in lab-scale drying.