Polymer Solid Electrolyte and All-Solid-State Battery Comprising the Same

High-Voltage Compatible Solid Electrolyte with Enhanced Ion Dissociation via Zwitterionic Polymer Matrix

This technology is a polymer solid electrolyte in which metal salts, such as lithium salts, are uniformly dispersed within a zwitterionic polymer matrix obtained by polymerizing zwitterionic compounds of a specific chemical formula.

Conventional polymer solid electrolytes suffer from low ionic conductivity, low lithium-ion transference numbers, and narrow electrochemical windows, making them difficult to use with high-voltage cathode materials. Furthermore, their unstable interface with lithium metal anodes has limited their practical application.

This technology involves applying a slurry of zwitterionic monomers and metal salts, followed by thermal polymerization to form a polymer matrix, which enhances ion dissociation and mobility while improving interfacial compatibility with electrodes and mechanical strength. It can be applied to next-generation all-solid-state batteries combining lithium metal anodes and high-voltage cathodes. By impregnating the cathode layer with the electrolyte to integrate it with the solid electrolyte layer, the internal cell interfacial resistance can be significantly reduced.

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Key Features:

• Zwitterionic polymer comprising structural units derived from the zwitterionic compound of Formula 1, forming an electrolyte with a metal salt
• Metal salt, such as a lithium salt, dispersed in a weight ratio of 1:0.05 to 1.5 relative to the zwitterionic polymer
• Step of applying a slurry containing the zwitterionic compound, metal salt, and organic solvent onto a substrate and evaporating the organic solvent
• Step of thermally polymerizing the applied zwitterionic compound at 110 to 150 °C to obtain the polymer solid electrolyte

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This invention was developed with support from the Ministry of Science and ICT for a single-ion conductor-based multidimensional free-form power system.

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