Industrial robots could soon run an entire eight-hour shift without a battery swap, but the technology that makes this possible carries a steep price tag. SK On, a major South Korean battery maker, is betting that manufacturers will pay a 4x premium for solid-state cells if the math on total cost of ownership works out.

What You Need to Know

Solid-state batteries promise higher energy density and longer runtime than lithium-ion, but they cost roughly four times more to manufacture. SK On is targeting industrial robotics as a first market where the added cost could be offset by reduced downtime and lower operating expenses. The company plans commercial solid-state cells for robots by 2028, with a faster sulfide-based variant arriving in 2029.

The TCO Math: Why Upfront Cost Is Not the Full Story

Speaking at the 2nd Battery Foundry Forum in Seoul last month, Ko Young-seok, executive vice president at SK On, argued that manufacturers must evaluate solid-state batteries through total cost of ownership (TCO) rather than sticker price alone. The TCO calculation factors in labor spent on swapping batteries, charging infrastructure and the opportunity cost of robot downtime.

Ko presented two competing approaches: battery swapping and ultra-fast charging. Both avoid the upfront premium of solid-state but carry their own hidden costs. Swapping requires extra battery packs and handling equipment. Fast charging degrades cells faster over time. Solid-state, he argued, could deliver lower TCO for factories that need continuous shift coverage.

Today, a lithium-ion battery accounts for under 2% of an industrial robot's total manufacturing cost, according to SK On. Switching to solid-state would push that share to around 8%. For a $55,000 robot, the battery cost jumps from roughly $1,100 to $4,400. This premium demands clear productivity gains.

  • Battery swapping: Requires extra packs and robotic handlers, raising facility costs but avoiding battery upgrade.
  • Ultra-fast charging: Degrades lithium-ion cells faster, increasing long-term replacement frequency and cost.
  • Solid-state TCO: Higher upfront but eliminates swap equipment and reduces charging degradation over robot lifetime.

SK On's Timeline and Competition

SK On completed its all-solid-state pilot plant in Daejeon last September, built with US solid-electrolyte firm Solid Power. The company is developing two chemistries: a polymer-oxide composite cell targeted for 2028 and a sulfide-based cell for 2029. This timeline has already been accelerated by one year. Samsung SDI, working with the same Solid Power technology, aims for 2027.

For applications with short duty cycles, a cheap lithium-ion pack or fast charging between tasks may remain the better economic answer. Ko acknowledged this directly. The pitch is aimed at robotics and industrial players that need sustained runtime and can afford the premium. Commercial EVs, however, remain a tougher market. Solid-state cells are still too expensive for mass-market electric cars, which must hit price points that consumers accept.

This dynamic means industrial robotics could become the proving ground for solid-state technology before it trickles down to vehicles. Manufacturers willing to pay for productivity gains may adopt solid-state sooner than EV buyers, who typically prioritize low upfront cost over long-term energy density benefits.

Why This Matters

The solid-state battery race is shifting from laboratory breakthroughs to commercial deployment. SK On's TCO argument matters because it frames adoption as an economic decision rather than a technical one. If early industrial users validate the cost math, it could accelerate investment in solid-state production capacity and drive costs down for all applications, including EVs.

Competition between SK On and Samsung SDI is already compressing timelines. Both companies target 2027-2029 for production, years earlier than earlier projections. The real test will come when factory operators compare the 8% battery cost share against the productivity gains of uninterrupted eight-hour shifts. For now, lithium-ion remains the default choice for most robot builders. Solid-state, as Ko put it, must prove it can earn its premium through lower total cost of ownership, not just through longer runtime.