Halide-based nanocomposite, solid electrolyte containing the same, method for manufacturing the same, and all-solid-state battery comprising said solid electrolyte

High-Voltage Stable Halide Solid Electrolyte Material with In-Situ Grown ZrO2 Nanonetwork

This technology is a halide-based nanocomposite that maximizes ionic conductivity and electrochemical stability by reacting lithium oxide precursors with metal halide precursors via mechanical milling, causing 5–10 nm ZrO2 to grow in-situ within the electrolyte and at the interface in a network structure.

Conventional sulfide-based solid electrolytes offer excellent ionic conductivity but suffer from low atmospheric stability and severe side reactions with cathode active materials in high-voltage environments. Existing halide-based electrolytes also face limitations in commercialization due to low ionic conductivity and high interfacial resistance.

This technology involves reacting lithium oxides (e.g., Li2O, LiNO3) with metal halides (e.g., ZrCl4) under specific mixing ratios and ball-milling conditions to produce a nanocomposite where 5–10 nm crystalline ZrO2 is formed in-situ within a Li-Zr-Cl host. It enhances ionic conductivity through the space-charge layer effect and improves interfacial stability and high-voltage cycle performance by blocking direct contact between sulfide electrolytes and the cathode. Applicable to cathode coating layers for all-solid-state batteries using high-nickel cathodes, sulfide-halide bilayer electrolytes, and cells for EVs and ESS, it prevents the decomposition of sulfide electrolytes during high-voltage operation, increasing cell design flexibility.

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Key Features:

• Halide-based nanocomposite for lithium-ion battery solid electrolytes represented by at least one of M1Oc-LiaM1Xb, LiX-LiaM1Xb, or M1Oc-LiX-LiaM1Xb
• Metal halide host where M1 is at least one of Ti, Zr, or Hf, and X is Cl, Br, F, or I
• ZrO2 nanocrystals with an average crystal size of 5–10 nm via TEM analysis, grown in-situ and formed as a network within the LiaM1Xb host
• Step of preparing a halide-based nanocomposite by solid-state mixing of a metal halide precursor with a lithium oxide precursor in an inert gas atmosphere

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