SK On’s energy storage system (ESS) has proven its fire safety compliance with global standards by suppressing thermal runaway in adjacent container batteries during a large-scale fire test simulating real-world conditions. Based on these results, SK On aims to accelerate its expansion into the global ESS market.
On Wednesday, SK On announced that its ESS meets the UL 9540A evaluation criteria, the North American benchmark for ESS fire safety testing. UL 9540A is a prominent safety standard in North America that assesses heat dissipation during battery thermal runaway.
The Large-Scale Fire Test (LSFT) replicates actual ESS fire scenarios to verify fire spread to adjacent containers. In March, the criteria for evaluating fire spread were strengthened to provide more precise standards.
Test results showed no thermal runaway in battery cells of adjacent containers due to heat from the fire-affected ESS container. The internal temperature of the container also met evaluation standards.
SK On explained that their ESS design disperses heat over extended periods, mitigating heat release rate spikes and reducing the risk of fire spreading to nearby containers.
With this UL certification, SK On plans to accelerate its global ESS market strategy.
In August, the company inked a supply deal for lithium iron phosphate (LFP) batteries with U.S. ESS firm NeoVolta Power. Last September, it secured a 1 GWh ESS supply contract with American renewable energy company Flatiron.
SK On is also ramping up efforts in the domestic market. In February, the company secured 284 MW, over half of the 565 MW total capacity in the second central contract market. Currently, it’s converting 3 GWh of its 7 GWh production line at the Seosan plant to focus exclusively on LFP batteries for ESS.
An SK On spokesperson stated that this test confirmed our ESS’s ability to suppress fire spread and maintain key safety performance under real fire conditions. It will continue enhancing the safety technology and product competitiveness to deliver tailored ESS solutions and expand the global market presence.
Meanwhile, SK On reported Q2 consolidated revenues of 2.946 trillion KRW (approximately 2.2 billion USD) and an operating profit of 821.8 billion KRW (around 615.2 million USD). This marks SK On’s first operating profit since Q3 2024 (24.1 billion KRW (about 18 million USD)) and represents the largest operating profit in the 19 quarters since its spin-off.
