SK on successfully develops new solid electrolyte to improve vehicle battery performance

According to foreign media reports, SK on, a battery manufacturer under South Korea's SK Group, has successfully developed a new oxide-based solid-state electrolyte, which has the world's highest lithium ion conductivity and is expected to improve all-solid-state batteries. -state battery) competitiveness.

The oxide solid electrolyte was jointly developed by SK on and a team led by Professor Park Hee-jung of the School of Materials Science and Engineering at Dankook University. And SK on has now applied for a patent for this technological achievement both inside and outside Korea.

SK on and its R&D team have adjusted the additives of the oxide solid electrolyte material LLZO (composed of lithium, lanthanum, zirconium, and oxygen). Compared with the lithium ion conductivity of existing products, the lithium ion conductivity of the new material has increased by 70%, achieving the highest conductivity in the world. Lithium ion conductivity refers to the movement rate of lithium ions in the electrolyte. Higher movement speeds will enhance battery output and charge faster. In addition, this technology can uniformly control the LLZO microstructure to ensure atmospheric stability. SK on said that usually, solid electrolytes are easily affected by humidity and carbon dioxide, so long-term exposure will reduce performance, while the oxide solid electrolyte shows high stability in this regard.

Although oxide solid-state electrolytes have lower ionic conductivity than sulfide solid-state electrolytes, they have higher chemical stability. The oxide solid electrolyte has low activity when reacting with the cathode material, thus suppressing problems such as the formation of lithium dendrites that can cause fires, allowing high-capacity lithium metal anodes to replace graphite anodes.

得益于氧化物固态电解质，电池容量得到显著增加。使用液态电解质的锂离子电池（LiB），其最大工作电压最高可达4.3 V，而使用氧化物固态电解质的锂离子电池的最大工作电压高达5.5V。SK on公司表示：“若将该新款氧化物固态电解质运用于电池生产中，理论上可以将电池容量提高25%。”

The oxide solid electrolyte material can be used not only for all-solid-state batteries based on NCM (nickel, cobalt, manganese) cathode materials, but also for curable lithium-sulfur batteries (lithium-sulfur batteries) and lithium-oxygen batteries (lithium-air batteries). ) and other next-generation batteries, as well as the polymer-oxide composite all-solid-state battery being developed by SK on.

If used in next-generation batteries, the oxide solid electrolyte could ensure both fire safety and long-distance driving. Choi Kyung-hwan, head of SK on's next-generation battery research center, said: "This solid electrolyte with both ionic conductivity and air stability is an innovative technology for manufacturing high-quality all-solid-state batteries and has a chain reaction." We will base this on Future technology competitiveness, taking the lead in seizing growth opportunities in the next-generation battery field. "

Currently, SK on is developing two all-solid-state batteries: polymer oxide composite solid-state batteries and sulfide solid-state batteries. SK on aims to produce early prototypes of the two batteries in 2026 and commercialize them in 2028. The company's next-generation battery pilot plant is currently under construction at the Battery Research Center in Daejeon, South Chungcheong Province and is expected to be completed in 2024.