Single-ion conducting polymer solid electrolyte and manufacturing method thereof

High-transference number solid electrolyte based on quaternary ammonium-fixed network polymers and cationic nanoparticles

This technology is a solid electrolyte that enhances both lithium-ion transference number and ionic conductivity by dispersing cationic inorganic nanoparticles, surface-treated with a metal oxide layer, into a network polymer matrix formed by photocuring monomers containing quaternary ammonium groups and multifunctional monomers.

Conventional dual-ion conducting polymer electrolytes suffer from low lithium-ion transference numbers because both lithium cations and anions are mobile, leading to concentration gradients and cell polarization that degrade battery performance. Furthermore, existing solid electrolytes have high interfacial resistance with electrodes and are unstable with lithium metal anodes, resulting in dendrite growth.

This technology fixes quaternary ammonium cation functional groups to the polymer backbone to suppress anion movement and maximize selective lithium-ion transport, while incorporating TiO2 and SiO2-coated cationic inorganic nanoparticles to reinforce interfacial stability and ionic conductivity. Additionally, it minimizes interfacial resistance by integrating the electrolyte and electrode through a solvent-free printing process. It can be applied to lithium metal batteries operating above 4V and the manufacturing of thin-film/flexible batteries based on printing processes, reducing cell polarization and enabling the production of integrated electrode-electrolyte cells without solvent drying equipment.

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Key Features:

• Network polymer polymerized from a photocurable composition containing monomers with quaternary ammonium groups and multifunctional monomers
• Cationic inorganic nanoparticles coated with a metal oxide layer containing titanium dioxide and silicon dioxide, dispersed within the network polymer
• Electrolyte included at 50–300 parts by weight, along with 10–300 parts by weight of inorganic nanoparticles per 100 parts by weight of the photocurable composition
• Step of forming a solid electrolyte by printing the curable composition with dispersed inorganic nanoparticles onto a lithium metal layer and then photocuring it

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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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