Solid electrolyte comprising a covalent organic framework and all-solid-state battery containing the same

Ion-channel solid electrolyte with polyalkylene oxide cross-linked network formed in lithium-functionalized COF pores

This technology is a solid electrolyte that enhances ionic conductivity and interfacial stability by using a covalent organic framework (COF) introduced with lithium-ion conductive functional groups as a scaffold and building lithium-ion channels through a polyalkylene oxide-based cross-linked polymer formed within its pores.

Conventional inorganic solid electrolytes suffer from low flexibility, high interfacial resistance with electrodes, and vulnerability to dendrite growth. Polymer solid electrolytes have limitations in high-voltage cathode applications due to low room-temperature ionic conductivity and a narrow electrochemical window.

This technology involves mixing a COF structure containing repeating units with lithium salts and a polyfunctional polyalkylene oxide monomer into a slurry, which is then pressurized, polymerized, and cross-linked to form a continuous 3D cross-linked polymer network within the COF pores. Applicable to all-solid-state lithium batteries using high-voltage cathodes and thin-film solid electrolyte cells under 100㎛, this technology simultaneously leverages the flexibility of polymers and the regular ion channels of crystalline frameworks in a single membrane.

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Key Features:

• -Covalent organic framework composed of repeating units with lithium-containing functional groups such as -COOM, -SO3M, and -PO4M
• -Polygonal framework structure containing repeating units on each side with pores 1.0 to 8.0 nm in diameter formed inside
• -Cross-linked polymer derived from polyalkylene oxide-based polyfunctional monomers containing two or more reactive functional groups such as acrylic, methacrylic, or thiol groups
• -Step of applying 5 to 250 MPa of pressure to a slurry composition containing the framework structure and polyfunctional monomer

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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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