Method for manufacturing electrolyte and battery comprising the same

Synthesis process for low-electron-conductive sulfide-based solid electrolytes using microwave-assisted thermal carbon shock

This technology enhances electrolyte crystallinity and suppresses the carbonization of organic solvent residues by loading wet-synthesized sulfide-based solid electrolyte precursor powder onto carbon or carbon composites and subjecting it to rapid heating and cooling via microwave irradiation (thermal carbon shock).

Conventional wet synthesis methods often lead to the carbonization of residual organic matter during high-temperature heat treatment, which abnormally increases the electron conductivity of the solid electrolyte, resulting in electrical leakage and internal short circuits in all-solid-state batteries. Furthermore, standard heat treatment methods struggle to balance improved crystallinity with the suppression of impurity formation.

This technology uses carbon or carbon composites as a heat source under microwave irradiation to complete high-temperature heat treatment in a short time, preventing carbonization while maximizing crystallinity. This process minimizes sulfur loss and inhibits the formation of impurities like Li3PO4, achieving both low electron conductivity and high lithium-ion conductivity. Applicable to mass-production processes for argyrodite-based electrolytes and automotive all-solid-state cells, this method secures high-ion-conductivity electrolytes with reduced short-circuit risks in just minutes.

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Key Features:

• Preparing a precursor solution containing lithium-based precursors and sulfide-based or oxide-based precursors
• Drying the precursor solution at 150 to 250 °C for 4 to 15 hours to produce precursor powder
• Performing a thermal carbon shock step by loading the precursor powder onto carbon or carbon composites acting as a heat source and applying microwave irradiation
• Carbon black, graphite, or SiC carbon composites loaded at 100 to 220 wt% relative to 100 wt% of the precursor powder

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This invention was developed with support from the Ministry of Science and ICT under the project for developing bridge technologies for large-area, 600Wh/L-class all-solid-state EV batteries.

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