Method for Manufacturing Lithium Secondary Battery Thick Films and Lithium Secondary Batteries Using Electrospray of Slurries Containing Sulfide-Based Solid Electrolytes

Large-Area Continuous Deposition of Sulfide Solid Electrolyte Thick Films via Cone-Jet Electrospray Process

This technology involves electrospraying a slurry of sulfide-based solid electrolyte powder dispersed in a non-reactive solvent, such as dichloroethane or dichlorobenzene, in cone-jet mode under a nitrogen atmosphere. This process forms uniform solid electrolyte or composite electrode thick films with excellent bonding properties on current collectors.

Conventional thin-film processes are costly due to high vacuum requirements, while pressing methods struggle with large-area scalability and interface quality. Casting methods also face limitations in controlling thickness and forming large-area films.

This technology achieves a stable cone-jet mode by maintaining an applied voltage-to-spray distance ratio of 1.0–1.5 kV/cm and a spray flow rate of 115–320 cm/h in a nitrogen atmosphere. By heating the current collector during deposition, it enhances the bonding and strength of the thick film without requiring a separate drying step. It enables the continuous stacking of composite slurries—including solid electrolytes, electrode materials, and conductive agents—to manufacture complete cells. Applicable to mass production lines and pilot coating equipment for all-solid-state batteries, it allows for the completion of cathode-electrolyte-anode stacks in a single process flow without vacuum equipment or high-pressure presses.

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Key Features:

• Preparation of a slurry by mixing sulfide-based solid electrolyte powder with at least one solvent from dichloroethane and dichlorobenzene in a weight ratio of 1:10 to 1:100
• Deposition of a lithium secondary battery thick film by electrospraying the slurry onto a current collector in cone-jet mode under a nitrogen atmosphere
• Heating the current collector while electrospraying the slurry during the deposition of the lithium secondary battery thick film
• Deposition of a lithium secondary battery solid electrolyte thick film by electrospraying a solid electrolyte slurry onto the first composite electrode thick film

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