SK On and SK Innovation are strengthening their push into the energy storage system (ESS) market through a partnership with Standard Energy, a domestic specialist in vanadium ion battery (VIB)-based ESS solutions.
Through the collaboration, the companies plan to expand their ESS portfolio beyond lithium iron phosphate (LFP) batteries to include highly fire-safe VIB technology, further reinforcing their focus on battery safety.
On January 5, SK On and SK Innovation signed a memorandum of understanding with Standard Energy in Daejeon to cooperate on secondary battery technology development and ESS business expansion, according to an announcement made on January 6. The signing ceremony was attended by Lee Seok-hee, CEO of SK On; Park Ki-soo, head of SK On’s Future Technology Institute; Kim Pil-seok, head of the Environmental Science & Technology Institute at SK Innovation; and Kim Boo-gi, CEO of Standard Energy.
The core of the agreement is technological cooperation to enhance the performance of high-safety, high-output VIBs optimized for short-duration ESS applications. ESS solutions are generally categorized into short- and long-duration systems based on storage time. Short-duration ESS typically store and discharge energy for less than four hours and are widely used in data centers and industrial facilities, where repeated high-power operation makes safety and output performance critical.
The three companies plan to combine their respective technological strengths to improve both performance and cost competitiveness. SK On will leverage its experience in mass battery production to expand cooperation with Standard Energy across the entire value chain, from raw material procurement to materials, cells, and battery management systems (BMS). The partners also plan to develop differentiated technologies, including large-area cell design.
SK Innovation will focus on improving material performance through electrolyte additive development, while also exploring cost-reduction measures by utilizing vanadium recovered from its refining processes.
With this partnership, SK On will broaden its product portfolio to include VIBs alongside nickel cobalt manganese (NCM) and LFP batteries, further advancing its safety-oriented battery strategy. VIBs use water-based electrolytes, eliminating the risk of fire and explosion, and offer high output, making them well suited for short-duration ESS applications.
Standard Energy’s VIB ESS solutions have already demonstrated their safety and reliability. Installed in central Seoul under a regulatory sandbox program by Korea’s Ministry of Trade, Industry and Energy, the systems have operated without a single incident. They have since been deployed in high-traffic subway stations and buildings, further validating their safety and performance.
Standard Energy is recognized as the world’s first company to develop VIBs specialized for ESS applications and has successfully commercialized the technology following extensive demonstrations. The company currently supplies VIB ESS solutions to multiple customers and gained international recognition when it was named the only Korean company on TIME magazine’s list of the World’s Best GreenTech Companies 2025.
Lee Seok-hee, CEO of SK On, said the collaboration will enable the joint development of fire-safe vanadium ion batteries for ESS, further strengthening the company’s product portfolio. He added that SK On aims to deliver new value to customers based on global-level technological competitiveness.
Kim Boo-gi, CEO of Standard Energy, said vanadium ion batteries have complementary characteristics to lithium-ion batteries and that working with SK On and SK Innovation will accelerate commercialization. He noted that the partnership aims to set a new standard for ESS that can be safely used in environments such as data centers, indoor facilities, and urban areas where both safety and performance are critical.
Meanwhile, the second round of Korea’s centralized ESS market bidding currently underway has identified fire safety as a key evaluation criterion. SK On plans to target the market with ESS solutions equipped with electrochemical impedance spectroscopy (EIS) technology, which can detect abnormal signs at least 30 minutes before a potential fire. The approach focuses on early detection to reduce risks, rather than responding after an incident occurs.
