Sulfide solid electrolyte slurry is a typically process-sensitive system. The electrolyte powder features fine particles and large specific surface area, which tends to agglomerate when mixed with binders and solvents. Gas adsorbed on powder surfaces gets entrapped into the slurry during stirring and forms tiny bubbles. If these bubbles remain in the electrolyte layer, ion transport channels will be blocked and the interfacial impedance rises. Uncontrolled gas content in the slurry greatly increases risks of pinholes and delamination in subsequent coating and film-forming processes.

News on October 26: a patent related to sulfide solid electrolyte from Huasheng Lithium Battery was published (Publication No. CN122968416A). It relates to the preparation of sulfide solid electrolyte with high ionic conductivity and stable interface, published on October 23. Patent layout for sulfide electrolyte materials is accelerating obviously. As the industry moves from formula development to verification and mass production, the process window for slurry preparation needs to be confirmed before production line implementation.

Electrolyte manufacturers usually determine the dispersion and defoaming window with real slurry samples during formula development, and then evaluate scale-up parameters accordingly. SIENOX engineers have recently received inquiries from multiple solid electrolyte material companies, who wish to conduct sampling and verification of sulfide-based slurries on small-volume equipment.

The SIENOX MIX60 adopted for verification is a laboratory model for formula evaluation with a 300ml processing capacity, suitable for parallel assessment of multiple formulas. It adopts a planetary revolution-and-rotation structure. Rotational shear fully wets and disperses fine powder particles, while centrifugal force from revolution pushes bubbles to the surface. Defoaming proceeds synchronously under vacuum (-98KPa) with a maximum speed of 2000rpm. Temperature control and atmosphere protection are optional custom configurations according to different systems. Its small capacity enables fast comparison of electrolyte formulas, and verified parameters can be transferred to pilot and mass-production machines.

The tested slurry shows no agglomeration or visible bubbles, with stable viscosity and gas content across batches. As solid-state battery materials advance rapidly toward mass production, vacuum defoaming mixers are undergoing intensive verification for sulfide systems. The supporting capacity of slurry defoaming machines for electrolyte slurry preparation and the applicability of laboratory vacuum defoaming mixers in formula development are worthy of early confirmation by material enterprises at the project initiation stage. The above content is compiled from public industry information; actual test data shall be subject to customer sampling verification.