After InterBattery 2026 — Where the Strategies of Korea’s Big Three Battery Makers Diverge (March 2026)

What Is at Issue: The Same Exhibition Hall, Three Different Weapons

At InterBattery 2026, Korea’s three battery makers all widened their gaze to applications beyond EVs (AI data centers, robots, ESS), but the weapons they put forward differed. Samsung SDI stressed the legitimacy of its prismatic technology and its solid-state timeline, LG Energy Solution its foundational technology and application portfolio, and SK On the systematization of safety. This article explains where the three strategies diverge and what the differences mean for patent risk and planning decisions.

Start with the industry context. InterBattery 2026 was held at COEX in Seoul from March 11 to 13, 2026. According to closing reports, 667 companies from 14 countries took part with 2,382 booths, and a record 77,250 visitors attended. The focus of the show was reported to have moved beyond EVs to ESS (energy storage systems), humanoid robots and solid-state batteries.

The tension lies in the numbers just before the event. On December 17, 2025, LG Energy Solution disclosed the termination of a battery supply contract with Ford worth about 9.6 trillion won. The contract had been to supply a total of 109 GWh to Europe from 2027 to 2032. On the 26th of the same month, the termination of a battery module contract worth about 3.9 trillion won followed, and cathode maker L&F was reported to have said that its supply contract with Tesla, worth about 3.84 trillion won, had been cut to about 9.73 million won, effectively the amount already delivered. With reliance on automaker demand alone becoming difficult, this article answers three questions: where exactly the three companies’ strategies diverge, how the patent figures in public statements should be read, and what planning and IP staff should track.

Basic Principle: Facing the Same Demand Cliff, Build Walls, Widen Roads, or Buy Insurance

The three companies’ choices can be read as different solutions to the same problem. By analogy, as traffic on the main road (EVs) falls, one company raises walls around its territory (patents and form-factor legitimacy), one opens new roads in several directions (application diversification), and one first designs the insurance needed whichever road is taken (a safety framework). It is less that one is right than that each company’s assets differ, so their choices split.

Two terms are worth clarifying. By outer shape (form factor), battery cells divide into prismatic cells housed in a metal can, pouch cells housed in an aluminum-film pouch, and cylindrical cells housed in a round can. A solid-state battery replaces the liquid electrolyte inside the cell with a solid electrolyte, and is regarded as a next-generation candidate that can reduce fire risk and raise energy density.

• Samsung SDI: unveiled for the first time the new names “PrismStack” and “SolidStack” for its prismatic and solid-state batteries, and showed for the first time a pouch-type solid-state sample for physical AI
• LG Energy Solution: under the theme “Original Innovator, Creating the Future of Energy,” exhibited AI infrastructure, robotics and drone applications in the largest booth, 540 m²
• SK On: Park Ki-soo, head of its Future Technology Institute (CTO), presented the “3P-Zero” safety strategy of Prevent, Protect and Predict, and the concept of “Trust Density”

Comparison: The Three Companies’ Announcements and Patent Figures

Company	Key announcements	Next-generation timeline, incl. solid-state (as announced)
Samsung SDI	First public showing of a pouch-type solid-state sample for physical AI, 700 Wh/L high-energy prismatic battery, warning of firm action on prismatic patent infringement	Mass production of pouch-type solid-state targeted for H2 2027
LG Energy Solution	AI infrastructure, robotics and drone applications; 94% nickel product in mass production and 95% product developed; sodium-ion 12 V and 24 V batteries in vehicle testing	Graphite-based solid-state (EVs) 2029, anode-free solid-state (robots, UAM) 2030
SK On	“3P-Zero” safety strategy (flame-retardant separator and non-flammable electrolyte, safeguard system and prismatic on-vent cell, AI-based development and manufacturing)	Sulfide-based solid-state 2029, AI risk-prediction system around 2027

What this table says: The solid-state target dates disclosed by the three companies range from H2 2027 (Samsung SDI) to 2029-2030 (LG Energy Solution, SK On), a gap of two to three years. Even under the same “solid-state” label, the first markets they target (robots, EVs, UAM) differ, making a simple speed comparison difficult.

Category	Disclosed figure	Speaker / counting party
Samsung SDI prismatic patents	More than 1,200 registered in the U.S. (claims domestic competitors hold around 30 to 40)	Research institute head Ju Yong-rak, 2026-03-11
LG Energy Solution patents	About 70,000+ filed (after March AGM) → as of May 2026, 100,000 filed and about 59,000 registered	CEO Kim Dong-myung’s remarks / reported company announcement
Growth in solid-state patent filings	Annual average 2021-2023: Samsung SDI 51.7%, LG Energy Solution 50.8%	Reports citing a February report of the Korean IP office

What this table says: The disclosed figures use different bases (U.S. registrations, worldwide filings, filing growth rates). Setting numbers with different bases side by side cannot establish superiority, and the numbers themselves read as part of each company’s messaging strategy.

Patent Perspective: The Target of the Warning Is “New Entrants to Prismatic”

What was disclosed: Samsung SDI’s warning did not name specific patent numbers or claims. According to reports, research institute head Ju Yong-rak issued the warning while referring to competitors’ plans to enter the prismatic segment, and explained that Samsung SDI first filed a prismatic battery patent in the U.S. in 1997. Therefore, the specific claims targeted by the warning cannot be identified from published patent information. This article does not guess at patent numbers either.

Insight: the contrast of “1,200 vs. 30 to 40” is a message not about defense but about the cost of entry. For a competitor that has focused on pouch cells to enter prismatic, it must newly acquire design elements unique to prismatic cells, such as the can-and-cap assembly, the vent (gas-release structure), the electrode stacking or winding method and thermal-propagation barrier structures. If the rights on the side that has accumulated these elements for a long time are thick, a latecomer must first pay the cost of FTO (Freedom to Operate, the infringement-risk review) and the time needed for design-around.

Conversely, the LG Energy Solution CTO’s reference to “30 years of R&D” and “tuition” turns the same logic back in other areas such as solid-state and materials. Because the two sides’ statements rest on rights in different technology areas, points where the scopes of the rights directly overlap do not emerge from public information alone.

Tracking points and avoidance approaches: For those considering a new entry into prismatic, it is realistic to divide the rights landscape by the following elements.

• Can-and-cap assembly and vent structure: these are parts unique to prismatic cells, so rights density is likely to be high
• Electrode stacking and winding method: since Samsung SDI attached the name “PrismStack,” the filing trend for stacked prismatic cells needs checking
• Thermal-propagation prevention structures: Samsung SDI’s 700 Wh/L prismatic cell and SK On’s prismatic on-vent cell both emphasized this area

Design-around scenario (counterargument): Early prismatic patents filed around 1997 may already have expired based on a term of 20 years from filing, so a latecomer can argue for a path of designing on expired technology. However, whether “more than 1,200 registered in the U.S.” counts only patents still in force has not been disclosed, and if recently filed improvement patents cover the detailed implementations needed for mass production, it may be difficult to build a competitive product on expired technology alone. In the end, infringement risk can only be judged by comparing individual product designs one-to-one with claims still in force.

Limits and Outlook

The announcements are impressive, but a gap remains between showing a sample and actual mass production. The original article stated that no company had firmly presented a specific mass-production date, but according to the reports reviewed, each company did present target dates (Samsung SDI pouch-type solid-state in H2 2027, LG Energy Solution 2029-2030, SK On sulfide-based in 2029). These are targets, however, and verification of yield and cost remains outside what public materials confirm.

The optimistic outlook is that ESS, data-center and robot demand fills the EV adjustment period and each of the three strategies succeeds in its own market. There is a counter-scenario as well. If volumes in the new applications fall far short of EV scale, application diversification may impose a larger burden of splitting development resources than the benefit of spreading fixed costs. And if patent sparring escalates from public warnings to actual litigation, the costs the three Korean companies spend on one another may reduce their capacity to compete with overseas rivals.

The strategic alternative is to reread the three companies’ announcements not as “product roadmaps” but as “rights roadmaps.” Checking the filing trends in the relevant areas every quarter, in line with the form factors, safety structures and solid-state timelines each company emphasized, makes it possible to gauge whether the announcements are backed by actual rights.

Practical action: Planning and IP staff considering adopting prismatic cells or switching suppliers should search Samsung SDI’s in-force U.S. registered patents divided into four elements, the can-and-cap assembly, the vent, electrode stacking and thermal-propagation prevention, and organize the expiry dates for each element in a table.

Items requiring verification

• The official source of the event theme cited in the original, “expansion to everything beyond EVs”
• Whether LG Energy Solution’s exhibition included satellite (aerospace) applications
• The speaker, date and counting basis of LG Energy Solution’s statement of “up to six times more next-generation battery patents”
• The original wording of the SK On sentence “absolute safety from the cell perspective alone is not enough,” and the source of the expression “AI digital-twin-based design”
• The content of SK On’s and POSCO Future M’s contract cancellation or investment reduction disclosures in late 2025
• The counting basis of Samsung SDI’s “more than 1,200 prismatic patents registered in the U.S.” (including whether they are in force)

Sources

1. Samsung SDI press release, Samsung SDI unveils solid-state battery for physical AI for the first time (2026-03)
2. Hankyung, Samsung SDI unveils solid-state battery for physical AI for the first time (2026-03-09)
3. Etoday, Samsung SDI “will not overlook prismatic battery patent infringement or technology theft” [InterBattery 2026] (2026-03-11)
4. Etoday, CTOs of Korea’s three battery makers: “technology is the answer to breaking the chasm” [InterBattery 2026] (2026-03-11)
5. Asia Today, SK On CTO Park Ki-soo “managing battery safety with AI”… unveils “3P-Zero” strategy (2026-03-11)
6. Edaily, SK On CTO: “battery competitiveness is ‘trust density'” (2026-03-11)
7. mtnews.net, LG Energy Solution unveils next-generation batteries specialized for AI and robotics at InterBattery 2026
8. Digital Daily, InterBattery 2026 closes successfully [Weekly Battery] (2026-03-14)
9. Korea Financial Newspaper, LG Energy Solution vs. Samsung SDI: a fierce battery patent contest (2026-03-30)
10. Financial News, LG Energy Solution surpasses 100,000 global patents (2026-06-21)
11. Maeil Shinmun, Secondary-battery sector shaken by LG Energy Solution contract termination (2025-12-18)
12. Hankyung, After LG Energy Solution, L&F also loses 3.8 trillion won (2025-12-29)

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