'If AI is the brain, the battery is the heart': Samsung SDI targets robot market with all-solid-state battery

Hyun Jang-seok, Samsung SDI global TPM team leader

'Physical AI demands repeated high output — battery determines performance'

21700 cylindrical cells already used in humanoid robots

All-solid-state 'Solid Stack' targets mass production in second half of 2027

Hyun Jang-seok, senior vice president and global TPM team leader at Samsung SDI's strategic marketing division. [Samsung SDI]

"If generative AI is the 'brain' that understands and processes information, then physical AI — robots and self-driving cars — is the 'body' that translates those decisions into real-world action. The battery that keeps that body moving is the 'heart.'"

Hyun Jang-seok, senior vice president and global TPM team leader at Samsung SDI's strategic marketing division, said in a written interview Thursday that batteries are playing an increasingly critical role in the era of physical AI. Beyond simply supplying power over a long period, batteries must deliver sudden bursts of high output in compact, lightweight spaces — repeatedly and without compromising safety, he said.

'Cylindrical battery production since 1998 — safety and high output, both'

Hyun said the performance requirements for physical AI batteries differ fundamentally from those for electric vehicles or IT devices. Humanoid robots need multiple motors to fire simultaneously — when rapidly accelerating or stopping joints, lifting heavy objects, or maintaining balance — drawing large amounts of power in fractions of a second. That demands high power density, low internal resistance, fast response times and effective thermal management. Safety is also non-negotiable, given that these robots operate in factories, offices and homes alongside people.

"If EV batteries compete on 'how far can you go,' the core competency for physical AI batteries is 'how much power can you deliver repeatedly and safely at the moment it's needed,'" Hyun said. "Physical AI operates in factories, offices and homes close to people, and it is exposed to shocks, vibrations and repeated high-output use — so safety is equally essential."

Samsung SDI's current weapon of choice is the cylindrical battery. "Since developing and shipping cylindrical batteries in 1998, we have built more than 20 years of related technology and mass-production experience," Hyun said. "Cylindrical cells can achieve both high output and high energy density at the same time, and standardized cells can be combined to flexibly configure packs that match a robot's spatial constraints and its voltage, capacity and output requirements."

He added that Samsung SDI's 21700-based products are already being used in humanoid robots, and that the company plans to expand its cylindrical battery solutions to optimize for an even wider range of robot architectures going forward.

Samsung SDI's cylindrical battery cells. [Samsung SDI]

All-solid-state batteries carry high costs — so premium robots come first

Samsung SDI has chosen the robot market as the first target for its next-generation all-solid-state batteries. The company recently unveiled its all-solid-state battery brand "Solid Stack" and presented samples designed for robots, with initial mass production targeted for the second half of 2027.

All-solid-state batteries require specialized materials and new manufacturing processes, making initial production costs high. Unlike the fiercely price-competitive EV market, the premium robot segment — where high performance takes priority — has more room to absorb those upfront costs. The robot market is also more favorable in terms of initial production scale. EVs require gigawatt-hour-level production capacity from the moment of market entry, whereas the battery capacity needed for a single robot is comparatively small.

"With the pilot line we have already built and the initial mass-production equipment coming in the second half of 2027, we will be able to respond smoothly to demand and establish an early foothold in the robot market," Hyun said. "The realistic sequence is to absorb volume in the robot market — which has high early-stage tolerance — stabilize yields, establish technical standards, achieve economies of scale, and then expand into the EV market."

All-solid-state batteries replace flammable liquid electrolytes with solid ones, reducing fire risk while enabling higher energy density. Increasing capacity within the same size and weight extends a robot's operating time; alternatively, maintaining the same operating time while making the battery smaller and lighter improves mobility.

"Samsung SDI is achieving both high energy density and safety simultaneously through sulfide-based solid electrolyte technology and our proprietary anode-free technology," Hyun said. "We have built a pilot line called the S-Line and have reached the stage of conducting customer evaluations."

Samsung SDI's all-solid-state battery, Solid Stack. [Samsung SDI]

Two-track strategy — cylindrical and all-solid-state: 'We will push the limits of robot performance'

Samsung SDI expects cylindrical and all-solid-state batteries to coexist even after all-solid-state technology reaches commercialization, with each serving different applications and performance requirements. Cylindrical batteries, whose cost, quality and reliability are well established, will continue to be used in mass-production markets such as robotics and mobility, while all-solid-state batteries are expected to gain greater value in humanoid robots and next-generation mobility platforms that demand higher energy density and safety.

"If high-performance cylindrical cells play a key role in enabling current robot capabilities, all-solid-state batteries are the technology that can push the limits of robots' operating time, weight reduction and safety one step further," Hyun said.

"Our goal is not simply to be a company that supplies batteries for robots, but to be a core partner that expands the performance limits of robots through battery technology," he added. "Drawing on two technological pillars — cylindrical cells and all-solid-state — we will enable robots to run longer, harder and more safely."

Hyun is scheduled to deliver a lecture titled "The Heart of Physical AI — Battery" at the Herald Business Forum 2026, to be held at the Shilla Hotel in Jung-gu, Seoul, on Sept. 29. This year's forum, themed "Beyond Follower: Transition to a Leading Economy," will cover growth strategies for future industries including AI, semiconductors, physical AI and the space industry.

eyre@heraldcorp.com