Lithium electrode coated with a protective layer and lithium secondary battery containing the same

Lithium metal electrode with dendrite suppression via 2D Si-SiOx nanosheet protective layer

This technology involves coating the surface of a lithium metal electrode with a 2D silicon-silicon oxide (Si-SiOx) composite or transition metal oxide protective layer. This suppresses lithium dendrite growth and prevents side reactions between the lithium and the electrolyte.

Due to its high reactivity, lithium metal often causes side reactions with liquid electrolytes, leading to dendrite growth, initial overpotential increases, and risks of fire or explosion. Furthermore, existing protective layer processes like ALD or UV are costly and suffer from low productivity.

This technology utilizes a 1–20 nm thick, large-area 2D Si-SiOx composite—consisting of crystalline silicon bonded to sheet-like silicon oxide—or a transition metal oxide, mixed with a binder to create a slurry that is coated onto the lithium metal surface and dried. Applicable to lithium metal battery anodes, high-energy-density drones, and electric vehicle batteries, it offers the advantage of mass-producing protective layers via roll coating without expensive vacuum deposition equipment.

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Key Features:

• Large-area 2D silicon-silicon oxide composite with crystalline silicon bonded to sheet-like silicon oxide
• Lithium electrode for lithium secondary batteries coated with at least one selected from nickel oxide, copper oxide, and black titanium oxide
• Step of mixing the composite or transition metal oxide with a binder and solvent to create a slurry, then coating it onto the lithium metal surface
• Step of drying the slurry-coated lithium metal at a temperature of 60 to 150 °C for 2 to 10 hours

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This invention was developed with support from the Ministry of Science, ICT and Future Planning for non-flammable alkali metal secondary batteries based on organic-inorganic hybrid ionic liquid electrolytes.

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