Lithium halide solid electrolyte, method for manufacturing the same, and all-solid-state battery comprising the same

Low-cost, air-stable zirconium-based Li2ZrCl6 halide solid electrolyte

This technology is a glass-ceramic lithium halide solid electrolyte composed of lithium (Li), a +4 oxidation state transition metal (such as Zr), and a halogen element, achieving both air stability and high ionic conductivity.

Conventional sulfide-based solid electrolytes suffer from low stability, as they degrade easily in the atmosphere. Existing halide alternatives also face limitations, requiring expensive rare metals like In or Y, which drives up manufacturing costs and hinders mass production.

This technology synthesizes a Li2ZrCl6 solid electrolyte based on Zr, an abundant and low-cost +4 oxidation state transition metal, using either a solid-state method via mechanical milling (e.g., ball milling) or a wet process using organic solvents. It can be applied to cathode composite layers and solid electrolyte layers in all-solid-state batteries for EVs, as well as mass-production pilot lines, reducing both dry-room management burdens and raw material costs.

‍

‍

Key Features:

• A compound represented by the chemical formula Li2ZrCl6, exhibiting a peak between 2θ 15° and 20° in X-ray diffraction analysis
• A lithium halide solid electrolyte showing a main peak between 2θ 30° and 35° with smaller peaks on either side
• A step of solid-state reacting lithium halide and zirconium halide precursors via mechanical milling, such as ball milling at 400 rpm to 700 rpm
• A solid electrolyte layer formed between the cathode and anode layers, containing a glass-ceramic lithium halide solid electrolyte

‍

This invention was developed with support from the Ministry of Science and ICT for the development of highly ion-conductive, solution-processable sulfide-based solid electrolyte technology for high-stability, room-temperature sodium all-solid-state batteries.

‍