Samsung and Hyundai Motor Group are moving beyond a simple parts supply relationship. The two companies are now jointly designing battery packs and developing manufacturing technology for next-generation solid-state batteries, which they hope to bring to market by the second half of 2027.
Joint Battery Pack Patent
A patent titled “Battery Pack and Vehicle Including the Same” was published on October 22 in South Korea’s patent database. It was jointly filed by Hyundai Motor, its affiliate Kia and Samsung SDI, Samsung’s battery unit. The design places gas vents at the bottom of the battery cells and creates a channel through the lower part of the pack. This lets hot gas escape during a thermal runaway, a dangerous overheating event, while combining the gas-venting and impact-protection spaces into one. The result is more room for energy storage. Five Hyundai and Kia researchers and two Samsung SDI researchers are named as inventors. The design is built around Samsung SDI’s prismatic battery, a rectangular cell format.
Growing Supply Relationship
Samsung SDI signed its first EV battery supply contract with Hyundai in October 2023. Under the agreement, it will supply prismatic batteries made at its Hungarian plant for Hyundai and Kia’s Europe-bound electric vehicles from this year through 2032. Hyundai and Kia have mainly used pouch-type cells, so the adoption of prismatic cells signals that they value the format’s energy density and safety. Samsung SDI batteries now power three models: Kia’s EV2, Hyundai’s Ioniq 3 and Genesis’s GV90 electric SUV.
Solid-State Research
The companies have filed nine solid-state battery patents, including divisional applications, from 2022 through 2025, and two have been registered. Samsung SDI is the lead applicant on seven of them. Early work focused on coating sulfide-based solid electrolytes, which degrade when exposed to moisture and can release toxic gas. From 2023, the research expanded to battery life and mass production. One filing covers temperature measurement for high-temperature isostatic pressing, a high-heat, high-pressure step in manufacturing, along with devices for preheating and moving battery cells.
Solid-state batteries replace liquid electrolytes with solid materials, offering potential gains in safety and energy density. Hyundai Motor Group Chairman Euisun Chung said in August that the group is researching the technology as part of its electrification strategy.
Robotics as the Next Frontier
The partnership is also extending into robotics. In February 2025, Hyundai, Kia and Samsung SDI signed a memorandum of understanding to co-develop high-performance robot batteries. Samsung SDI would handle materials and cell design, while Hyundai and Kia’s Robotics Lab would integrate the batteries into robots and test them. Humanoid robots need strong bursts of power, compact batteries and strong impact protection, because they work alongside people. Samsung SDI is preparing cylindrical and solid-state robot batteries and believes solid-state technology could extend humanoid operating time to as much as eight hours. Hyundai plans to deploy Boston Dynamics’ humanoid Atlas at its Metaplant in Georgia, in the United States, in 2028, and it aims to produce 30,000 robots a year. However, neither company has confirmed that the jointly developed battery will be used in Atlas.
Executive Engagement
On the 9th, Samsung Electronics hosted “HMG Appreciation Day” at its Seocheon Training Center in Yongin, Gyeonggi Province. The event drew 177 guests, including Hyundai Motor Group executives and their spouses. It was the first large-scale invitation event Samsung has held for a single South Korean group. Samsung Electronics Vice Chairman Jeon Young-hyun and Hyundai Motor Group Vice Chairman Jang Jae-hoon presided. Jang said the companies were expanding cooperation into robotics and energy, and Jeon said Samsung’s technology would help “open up new value and infinite possibilities.” Solid-state batteries and cell and pack modules were on display.
The two companies’ relationship dates to 2020, when Chung and Samsung Electronics Chairman Lee Jae-yong exchanged visits to discuss next-generation EV batteries. That exchange preceded the 2023 supply deal.
Financial Pressure
Samsung SDI reported third-quarter consolidated operating profit of 407.8 billion won (about $303.8 million), a turnaround from an operating loss of 591.3 billion won (about $440.5 million) a year earlier. Energy storage systems drove much of the improvement. Analyst Park Jin-soo of Shinyoung Securities expects the automotive battery division to return to losses in the fourth quarter, as government subsidy benefits fade and battery production for BMW and North American EVs declines, despite higher supply volumes to Hyundai and Kia in Europe.
The key questions now are whether the joint research will reach production vehicles, whether the companies can secure mass-production technology for solid-state cells, and whether the partnership expands into robotics as planned.
