The Korea Herald
America’s battery war with China is no longer just about EVs. It is now moving into defence, where military demand, supply-chain security, and Korean manufacturers are creating a new power play.
US military cuts Chinese batteries; Korea steps in
US efforts to reduce reliance on Chinese battery supply chains are expanding beyond electric vehicles and energy storage into the defense sector, opening new opportunities for Korean battery makers navigating a slowdown in EV demand.
The US Department of Defense signaled its intent to deepen partnerships with Korea to standardize batteries for military use at a Korea-US defense battery cooperation seminar held during InterBattery 2026 in Seoul earlier this month — a move aimed at lowering costs and accelerating mass production.
According to Eric Shields, senior battery advisor in the office of the US Secretary of Defense, more than 5,000 battery types are currently used across systems ranging from infantry gear and jammers to drones, submarines and space-based weapons.
“Batteries should be standardized like ammunition and fuel,” Shields said, noting that widely used formats such as 18650 cylindrical cells could play a central role in improving interoperability.
The Pentagon’s push reflects a broader effort to establish non-Chinese supply chains. Under the National Defense Authorization Act, the US will effectively bar Chinese-made batteries from new weapon systems starting in 2028, with restrictions expanding to legacy platforms such as submarines from 2031.
The urgency stems from China’s overwhelming control of battery production. Lisa King, director of advanced battery strategy at LEAP Manufacturing, said about 90 percent of cylindrical batteries used in defense and electronics are currently made in China — a concentration that poses risks in a sector tied directly to national security.
The initial focus on cylindrical batteries, particularly 18650 cells measuring 18 millimeters in diameter and 65 millimeters in length, reflects their widespread use in lighter systems such as military radios, drones and small unmanned vehicles. US officials said standardization will gradually extend to larger formats, including prismatic batteries used in heavy platforms such as submarines and armored vehicles.
Korean battery makers are emerging as key beneficiaries of the shift.
Samsung SDI is seen as having a strong edge in cylindrical lithium-ion batteries, supported by its leading position in small-format cells used in data center backup units and consumer electronics. The company held about a 50 percent share of the global battery backup unit market in the fourth quarter of last year, according to its earnings call.
A senior researcher at a major battery firm said companies with existing cylindrical production lines are well placed to maintain a cost advantage, as they can adapt capacity without significant new investment.
“Defense orders tend to be stable and placed in fixed volumes, meaning even relatively modest margins compared to EVs can be viable,” the researcher said.
He added that smaller formats such as the 18650 are less expensive to manufacture while offering proven reliability across applications.
“These batteries have also demonstrated low defect rates after extensive testing under extreme conditions, which is critical in defense settings, where malfunctions can result in life-or-death situations — making cylindrical cells particularly well suited for military use.”
Samsung SDI is also expanding into larger battery formats. The company has co-developed a submarine-grade prismatic lithium-ion battery with Hanwha Ocean and Hanwha Aerospace, with deployment expected between 2027 and 2028.
Other Korean battery makers are also stepping up their defense presence.
LG Energy Solution has built credibility in high-performance environments, supplying batteries for aerospace projects linked to NASA and SpaceX. It is also indirectly involved in US defense electrification through GM Defense, which uses battery technologies from LG Energy Solution and its joint venture Ultium Cells to adapt EV platforms for military applications.
GM Defense has reportedly joined Pentagon-backed projects to test EV batteries for directed energy systems — weapons that use focused energy such as lasers — while also participating in battery standardization efforts.
SK On is supplying high-nickel pouch batteries for unmanned systems developed by Hyundai Rotem and is in talks with US and European defense firms to supply batteries for AI-powered submarines and electric vertical take-off and landing aircraft.
For Korean battery makers, the defense sector offers a potential new growth engine as EV demand slows. Unlike the highly competitive EV market, defense contracts tend to be stable and long-term, with fixed volumes that support predictable revenue streams.
“Excluding Chinese players, Korean battery makers are effectively Washington’s only viable alternative with both advanced technology and mass production capacity,” an industry source said.
As the US accelerates efforts to decouple from Chinese suppliers, Korea’s battery industry is increasingly positioned at the center of a strategically driven market — one shaped as much by national security priorities as by commercial demand.
Credits: TCA, LLC.