South Korean battery startup UBATT is targeting aerospace and defense applications such as drones and unmanned aerial vehicles (UAVs) with high-energy-density lithium-metal batteries, aiming at applications that require 400–500 Wh/kg or more and are difficult for conventional lithium-ion batteries to serve.
The company is also positioning itself to benefit from growing US efforts to reduce reliance on Chinese suppliers in defense supply chains.
UBATT Managing Director Yoo JongTae said drones are evolving from auxiliary equipment into increasingly important assets on the modern battlefield. The trend extends beyond aerial systems to unmanned surface vessels, reconnaissance platforms, unmanned ground vehicles and military robots.
Batteries for such systems must deliver more than high energy density, Yoo said. They also need high power output, low weight, vibration resistance and reliable operation under low-temperature and low-pressure conditions.
Military drones, in particular, can require bursts of high power during vertical takeoff and landing, rapid maneuvering and emergency avoidance. High-altitude missions introduce another challenge, as atmospheric pressure falls well below ground-level conditions.
If cell packaging and structural designs are inadequate, reduced external pressure can contribute to swelling in pouch cells, damage seals, and potentially cause electrolyte leakage.
Lithium metal targets the limits of conventional Li-ion
UBATT is therefore developing lithium-metal batteries and testing them specifically for drones and other aerospace platforms.
While today's EV battery cells typically operate around the 300 Wh/kg range at the cell level, aerospace and defense applications can demand 400 Wh/kg and, in some cases, more than 500 Wh/kg.
Lithium metal is considered one of the leading candidates for moving beyond conventional lithium-ion energy-density limits. A lithium-metal anode offers substantially higher theoretical specific capacity than a graphite anode.
UBATT has already established a lithium-metal battery production line and worked with equipment suppliers to jointly develop manufacturing processes, according to Yoo.
Following approximately one to two years of process optimization, the company has begun testing cells exceeding the 500 Wh/kg class, alongside pouch-cell validation and drone flight tests.
For battery startups, competing directly in electric vehicles and energy storage systems (ESS) is increasingly difficult. Large battery manufacturers already operate massive production networks capable of competing aggressively on both cost and capacity.
Aerospace and defense offer a different market structure.
Orders tend to involve smaller volumes, greater product variety, and more customization, while customers are generally less sensitive to battery prices when performance is mission-critical. That creates an opening for startups such as UBATT to commercialize emerging battery chemistries without immediately matching the manufacturing scale of established EV battery giants.
Defense supply-chain reshoring opens a window for Korean suppliers
US efforts to reduce dependence on Chinese components in defense supply chains could further strengthen that opportunity, particularly in aerospace and defense markets where supply security is becoming increasingly important.
South Korean media reported in March 2026 that US defense officials and executives from defense contractors had held closed-door meetings in South Korea with smaller Korean battery companies, including UBATT, Vitzrocell, LiBEST, BEI, and JR Energy Solution.
Some Korean battery suppliers had reportedly begun supplying cells to US customers by late 2025, highlighting Washington's search for alternative sources outside China.
The market opportunity is also expanding. MarketsandMarkets forecasts the global drone battery market will increase from US$1.59 billion in 2025 to US$2.41 billion by 2030, representing a compound annual growth rate of 8.7%. Military drones are expected to represent the largest platform segment by the end of the forecast period.
South Korea is pursuing similar localization goals. The government has announced plans to deploy roughly 60,000 unmanned systems by 2029, while seeking to increase the share of domestically sourced components.
For startups such as UBATT, aerospace and defense could therefore provide an important bridge between advanced battery R&D and commercial deployment.
Lithium-metal technology, however, remains far from mature. Challenges including dendrite formation, cost, cycle life, safety, and manufacturing yield still need to be overcome.
Drones may offer an attractive initial market because some applications impose less demanding cycle-life requirements than passenger EVs. But whether companies can use those early deployments to resolve the fundamental technical and manufacturing challenges of lithium-metal batteries will ultimately determine whether the technology can compete more broadly with mainstream lithium-ion chemistry.
Article translated by Scarlett Yu and edited by Jerry Chen
