[Edaily Reporter JAEMIN SONG ] “If you fall behind in investing, you could easily be left behind.”

The fact that South Korea’s three major battery manufacturers have successively disclosed patents related to all-solid-state batteries this month stems from this underlying sense of urgency regarding future strategic industries. Just as companies have recently been paying lip service to the idea of “slowing down” on artificial intelligence (AI) while failing to actually halt investment, the global competition for leadership in all-solid-state battery technology is also intensifying.

Beyond Materials to Manufacturing Processes… K-Battery Prepares for Mass Production at CHAEVI CO., LTD

An analysis by Edaily of the patents recently disclosed by South Korea’s top three battery manufacturers revealed that these patents cover not only materials—such as cathodes—but also technologies related to manufacturing processes, including stacking and compacting electrodes. This suggests that the scope of technology acquisition is expanding from materials to the actual processes required for production.

Since all-solid-state batteries use a solid electrolyte instead of a liquid one, it is crucial to ensure that the electrodes and electrolyte—both in a solid state—make uniform contact. If contact is uneven, resistance increases during the movement of lithium ions, which can lead to reduced performance. This is why the ability to precisely control manufacturing processes—such as stacking and compression—and to repeat production with consistent quality is considered a key challenge for commercialization, in addition to material performance.

SAMSUNG SDI CO.,LTD., which has announced the earliest mass production timeline (the second half of next year), has expanded the scope of its technology to include manufacturing processes in this latest patent as well. The company disclosed manufacturing technology involving the assembly, stacking, and compaction of electrodes and gaskets, as well as cathode technology utilizing sulfide-based solid electrolytes. It is currently conducting customer validation at the “S-Line” pilot line at its Suwon Research Center. Pouch-type products targeting physical AI applications, such as humanoids, are also under development.

LG Energy Solution has disclosed patents closely tied to actual production processes. A prime example is a manufacturing method that continuously supplies all-solid-state battery components and bonds them using a roll-to-roll process. The company is pushing forward with the construction of a pilot line at its Ochang Energy Plant and is also developing mass production processes. The company aims to commercialize graphite-based all-solid-state batteries for electric vehicles by 2029 and anode-free all-solid-state batteries for humanoid robots by 2030.

The patents disclosed by SK On focused on technology to reduce the internal resistance of all-solid-state batteries. This method involves applying a conductive layer between the current collector, active material, and solid electrolyte to facilitate the smooth movement of ions and electrons. While validating prototypes at the Daejeon Future Technology Institute’s pilot plant, the company is also collaborating with U.S.-based Factorial Energy on manufacturing. The goal for commercializing sulfide-based all-solid-state batteries is 2029.

High Bar to Commercialization… but Competition Among South Korea, China, Japan, and Germany Is Intensifying

There are many hurdles to overcome before all-solid-state batteries can rapidly replace existing lithium-ion batteries. Key challenges include the high cost of materials such as solid electrolytes, resistance at the interfaces where solids meet, durability issues, and yield rates during mass production. In particular, since energy density and safety in existing lithium-ion batteries are steadily improving, some observers point out that all-solid-state batteries must demonstrate clear competitive advantages in terms of both price and performance.

Park Cheol-wan, a professor in the Department of Automotive Engineering at Seojeong University, said, “Lithium-ion rechargeable batteries have seen significant improvements in energy density and safety compared to the past,” adding, “All-solid-state batteries must demonstrate that they can be technically and commercially competitive compared to existing technologies.”

Nevertheless, global technological competition is actually accelerating. China’s BYD is pushing for small-scale production of all-solid-state batteries next year, and CATL is also aiming for trial production in the same year. Japan’s Toyota is establishing a supply chain for sulfide-based solid electrolytes with Idemitsu Kosan and is pushing for the commercialization of electric vehicles equipped with all-solid-state batteries next year or the year after.

European automakers have taken the lead in real-world vehicle validation. Germany’s Mercedes-Benz is conducting on-road tests with an EQS prototype equipped with all-solid-state cells from U.S.-based Factorial Energy. BMW is also testing an i7 prototype featuring all-solid-state cells from U.S.-based SolidPower on public roads. This marks a broadening of the competitive landscape, moving beyond pilot production by battery manufacturers to a stage where automakers are verifying performance and feasibility in actual vehicles.

In particular, there is a growing trend among Korean companies to focus on solid-state batteries as a “game-changer” that could reverse their lag behind China in battery supply chain leadership. The goal is to establish a technological barrier that creates a significant lead in order to catch up with China. A senior industry official stated, “Batteries are a core strategic industry for the nation,” adding, “The government also needs to provide full support to secure solid-state technology capabilities.”