Polymer composite with improved adhesion and manufacturing method thereof

Inorganic-coated separator with enhanced interfacial covalent bonding via oxygen plasma and low-dose radiation

This technology induces chemical covalent bonds, such as Si-O-C and Si-O-Si, between a polymer substrate and an inorganic thin-film layer by exposing the surface to 1–100 kGy of radiation. This process significantly improves interfacial adhesion.

Conventional polymer composite separators suffer from poor stability due to thermal shrinkage at high temperatures. Furthermore, weak bonding between the polymer substrate and the inorganic layer often leads to delamination, which can cause internal short circuits and battery explosions.

This technology involves treating a porous polymer substrate with oxygen plasma to impart hydrophilicity, depositing an inorganic thin film (e.g., SiO2, Al2O3), and then applying 1–100 kGy of radiation (e.g., electron beam) to strengthen the chemical bonds at the interface. Applicable to heat-resistant lithium-ion battery separators, high-safety EV cells, and water treatment membranes, it prevents inorganic layer delamination without adhesive binders, reducing the risk of internal short circuits.

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Key Features:

• Treating a porous polymer substrate with oxygen plasma to impart surface hydrophilicity
• Depositing an SiO2 or Al2O3 inorganic thin film on at least one side of the oxygen plasma-treated porous polymer substrate
• Increasing interfacial adhesion by irradiating the inorganic thin film with 1 kGy to 100 kGy of radiation
• Inorganic thin film formed to a thickness of 1 nm to 1 ㎛ via chemical vapor deposition or atomic layer deposition

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This invention was developed with support from the Ministry of Science, ICT and Future Planning for the development of organic environmental pollutant-reducing photoelectrochemical hydrogen production.

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