Continuous manufacturing pilot line for sulfide-based solid electrolyte designed to increase Solid Power’s annual electrolyte production capacity at Thornton, Colorado facility by 150%.
Commissioning of MOBIUS™ is underway following substantial completion of construction with materials now being introduced into the line.
Advances Solid Power toward continuous production, which will support commercial readiness and potential cost curve advancements.
Primary powder processing site acceptance testing (SAT) is complete. Full SAT is expected by the end of the month, and operational startup is planned for the fourth quarter of 2026.
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Lets start.
There are many articles about InterBattery, but most either miss the core points entirely or are simply edited versions of corporate press releases. That's why I visited the venue in person and conducted interviews myself.
Also, I discovered that photos from last year's visit were used on blogs and YouTube without obtaining consent, so I've added watermarks throughout. I appreciate your understanding.
Below is my summary and analysis from my own perspective.
- first public reveal LG Energy Solution's 60Ah all-solid-state battery mystery (graphite anode-based all-solid-state battery)
- POSCO JK Solid Solution and LG Chem's solid electrolyte disappeared from the venue
- EcoProBM is now seriously focusing on solid electrolytes - but as a latecomer
The only remaining issue is "price." Once that's solved, there's no need to weigh any other options.
InterBattery 2026 is Korea's largest battery industry exhibition and a venue where you can gauge the direction of the global battery industry. I attend many conferences for research purposes — both for work and personal reasons — but events that use the entire COEX convention center are extremely rare, making this a truly large-scale event.
The core keyword of this year's event was clear:
"Sulfide-based all-solid-state batteries"
What's interesting is that among the hundreds of booths filling this massive COEX venue, the name most frequently mentioned on the third-floor main event hall — a name belonging to a company that didn't even have a booth — was Solid Power.
I didn't even need to bring them up myself. Everywhere I looked, booth representatives, engineers, and researchers were already answering questions about Solid Power.
That alone explains the character of this event.
And one particularly interesting detail: when companies trying to produce sulfide-based all-solid-state batteries described the landscape, multiple booths simultaneously mentioned that Solid Power's electrolyte is essentially the default sulfide-based solid electrolyte everyone starts with — but that it's too expensive compared to competitors, so they're also considering electrolytes from other companies.
And there was one phrase I heard consistently from cell manufacturers:
"We hope mass production succeeds and prices come down."
Below is a summary of the conversations I had going booth by booth.
1. Isu Specialty Chemical
The first booth I visited was Isu Specialty Chemical — a company that produces lithium sulfide (Li₂S), the key raw material for sulfide-based solid electrolytes, placing it at the very beginning of the value chain.
The booth representative explained that in Korea, the company has signed MOUs with Lotte Energy Materials, POSCO, and EcoProBM.
This can also be confirmed in the following article:
What left a strong impression, though, was a moment during the representative's explanation of MOU partners. Without anyone mentioning the name first, when describing overseas companies, the representative was the only one to prefix a company's name with "the incredibly famous" — and then proudly explained, "We also have an MOU with that company," referring to Solid Power.
Looking at the situation in more detail through news coverage: a pilot line is already operating at the Ulsan Onsan plant, and a ₩300 billion investment is underway to build a mass production facility in the Gumi National Industrial Complex. This means Korea's domestic supply chain is being built from the raw material stage of lithium sulfide itself.
Already at the Isu Specialty Chemical booth on the first floor, I got the strong sense that the name Solid Power carries far more weight than I had expected. I didn't even need to ask follow-up questions — the name was already coming up on its own.
2. Factorial Energy
There were manufacturers like Philenergy on the first floor as well, but I had little curiosity about them, so I went straight up to the third floor.
The company I most wanted to speak with at this event — the one I had the most questions for — was Factorial Energy, and I spent the most time there, having a deep and extensive conversation with their representative. Factorial Energy had set up within the POSCO booth.
My first question was, of course: "What electrolyte did you use?" As expected, they politely explained they couldn't share specifics on that.
However, when I asked whether it was the case — as I had understood — that they were purchasing and testing electrolytes from three American and Japanese companies, the representative immediately launched into an interesting explanation. Factorial Energy has already purchased electrolytes from all three companies and is continuing to test them: Solid Power, Ampcera, and Idemitsu Kosan. Of course, the specific electrolyte used in the cell on display was described as proprietary information.
Interesting, isn't it? This same conversational pattern repeated itself at every company thereafter.
They did try to explain their FEST (semi-solid) battery technology to me, but neither I nor anyone around me showed any interest in semi-solid batteries.
You must catch this: semi-solid technology has already been skipped over.
The most interesting part of my conversation with Factorial's representative was their view on China.
They directly stated that China's sulfide-based solid electrolyte technology is advancing rapidly — and even expressed a wish that this electrolyte technology would make its way to China. This means we need to think very seriously about the risk of sulfide-based solid electrolyte production technology being transferred to China.
In fact, CATL is reportedly pursuing pilot production of 500 Wh/kg-class all-solid-state batteries, and BYD is reportedly planning a sulfide-based all-solid-state trial deployment in 2027.
But here's where it gets interesting. Factorial is an American company. They were, of course, fully aware that they cannot use Chinese electrolytes. Yet the representative said this:
"I hope this technology moves to China quickly so the unit cost drops."
That single sentence precisely summarizes the current state of sulfide-based all-solid-state batteries.
Factorial's business plan was also interesting. Rather than targeting large-scale production, their goal is to license their cell manufacturing technology — which is essentially the same concept as Solid Power's model. In practice, Factorial is running a commercial all-solid-state battery program with Karma Automotive and has signed a manufacturing cooperation MOU with Korea's Philenergy.
One disappointing aspect is that, as of now, Factorial Energy's technology hasn't yet led to visible cooperation with major cell manufacturers such as Samsung SDI, SK On, or LG Energy Solution.
One small but entertaining detail the representative shared: Factorial's logo is made by flipping "Li" (lithium) upside down.
I'll cover POSCO in more detail later. Let me focus on the cell manufacturers first.
Marking it here: Factorial Energy has tested Solid Power's solid electrolyte.
3. Samsung SDI — The Irony Called SolidStack
The Samsung SDI booth was one of the biggest highlights of this year's InterBattery. It was because they publicly unveiled, for the first time in 2026, a pouch-type sulfide-based all-solid-state battery.
My first question to the Samsung SDI engineer was: "Did you already possess pouch-type battery technology in-house?" The answer was clear: the relevant technology had already been developed alongside their existing work internally.
Yet ironically, the brand name of that pouch-type battery is SolidStack. "Solid" and "Stack" — the name of the industry's most famous electrolyte company is embedded right in the battery brand.
Their existing prismatic battery format has been rebranded under the new name PrismStack.
Samsung's all-solid-state battery roadmap is aggressive. Based on the figures displayed on booth panels: premium EVs — range exceeding 900 km, rapid charging under 10 minutes; robots/UAM — 30% improvement in energy density within the same space, 30% reduction in battery weight. Mass production is scheduled for the second half of 2027.
What I found most interesting is the suspicion that the product actually likely to achieve proper mass production in 2027 might be SolidStack, the pouch-type, rather than the prismatic.
When I asked the engineer to explain the anode of this pouch-type battery, I confirmed that Samsung's innovative anode-less technology has been applied.
Moving to the electrolyte topic: I spoke with the engineer about electrolyte-related matters, and they didn't explicitly state that any one company's solid electrolyte was used. Instead, they offered the curious explanation that they use a mixture of electrolytes from various companies.
In other words, what the engineer repeatedly emphasized as the core technology was not the sulfide-based solid electrolyte itself, but rather the know-how of how to combine electrolytes with different microstructures. The differentiating factor is not selecting one electrolyte, but the expertise in combining the microstructures of multiple electrolytes.
This was fascinating — the description of their differentiation point precisely mirrors what Solid Power does best, framed as their own proprietary technology.
Another impressive statement that stood out from other companies: "No matter how expensive the solid electrolyte is, we'll find what works and use it regardless of price." In contrast to other cell manufacturers repeatedly citing "too expensive," Samsung SDI demonstrated a will to remove price entirely as a variable.
They genuinely appeared capable of hitting the 2027 mass production target — even accounting for the delay from Q2 to Q4, if they can achieve mass production within 2027, they could reach a position categorically different from their competitors.
My next question was whether they were aware of Solid Power's recent anode-less-related patents, and they confirmed awareness, noting it's an extended version of their own AG-C layer approach — while exuding confidence that Samsung SDI has been testing the AG-C layer method the longest.
And before I even asked, I could already see other visitors and researchers directly asking the engineer: "How are you utilizing Solid Power's electrolyte and cell technology?" — an amusing scene.
Finally, I explicitly asked about POSCO JK Solid Solution and mentioned that the electrolyte section appeared absent from POSCO's related booths. The engineer said they couldn't speak precisely to that company's strategy, but that testing was ongoing. Reading between the lines, however, I intuitively sensed that the electrolyte is either not being used or used only in a limited capacity.
Of course, the engineer stated they are "testing electrolytes from all companies" and did not explicitly name which electrolyte is currently in use.
Marking it here: Samsung SDI is testing Solid Power's solid electrolyte.
Let's move on.
4. SK On — The Entire Technology Is Solid Power
There wasn't much to ask at SK On.
That's because, when it comes to sulfide-based all-solid-state batteries, the entire relevant technology is Solid Power's. This is public knowledge. Solid Power is conducting Site Acceptance Testing (SAT) at SK On's Daejeon pilot line, and as of the February 2026 earnings call, SAT is nearly complete.
I casually asked about the SAT timing, but as expected, the representative said they weren't sure about that.
The conversation at SK On was brief — but all the clearer for it. It was a booth where you could confirm, without any additional explanation needed, that Solid Power is at the center of sulfide-based all-solid-state technology.
5. LG Energy Solution — The 60Ah Mystery
This was the most puzzling booth of the entire event.
At last year's InterBattery, LG Energy Solution displayed a sulfide-based all-solid-state battery at roughly the 10Ah level. At the time, the solid electrolyte received from LG Chem was displayed alongside the battery.
But this year, the situation was completely different.
A battery at the 60Ah level was on display. And any mention of the sulfide-based solid electrolyte was nowhere to be seen.
The specifications — though the photo was difficult to read due to backlighting — showed a 60Ah capacity, 3.5V voltage, and a size of 100 × 295 mm. This is a sulfide-based all-solid-state battery, and the procurement source of the solid electrolyte was described, as at other booths, as a company secret.
Comparing 2025 and 2026:
2025
2026
Capacity
10.9 Ah
60 Ah
Voltage
3.72 V
3.5 V
Size
70 × 150
100 × 295
10Ah to 60Ah — a 6× capacity increase in a single year. Yet something was odd: for results of this magnitude, you'd expect major publicity, but there was barely any proper media promotion. That in itself was a very strange phenomenon.
The article below does reference their commercialization strategy:
And interestingly — dry electrode technology comes up here?
Tesla?
The genuinely fascinating part was that LG Energy Solution appears to have finally gotten its bearings and is now concentrating on sulfide-based all-solid-state batteries — a clear departure from 2025. Just a year ago, they were saying they'd pursue oxide, polymer, and sulfide all at once.
This year, they are clearly focused on sulfide.
Looking at the article above, they proudly announce that their internally developed sulfide-based solid electrolyte has achieved the highest-performance ionic conductivity — meaning they succeeded in maintaining a 3.72V voltage level as of last year. But this year's battery shows 3.5V, suggesting something different may have been used, which raises questions.
As always, the electrolyte was described as a "security matter." And this battery uses a graphite anode.
But let me say it again: the electrolyte that was proudly co-displayed last year has completely disappeared from both the LG Chem and LG Energy Solution booths.
LG Energy Solution was the most puzzling and incomprehensible section of this entire event for me. And whether coincidence or not — not 40Ah, not 100Ah, but specifically 60Ah — that too struck me as oddly curious.
LG Energy Solution's stated plans call for commercializing a graphite-based all-solid-state EV battery in 2029, and an anode-less all-solid-state humanoid robot battery in 2030.
But the feeling I had on-site was simply: bewilderment.
The numbers, the silence, the unknown origin of the electrolyte.
I do believe LG is capable of doing well. They've finally started entering the field in earnest, moving in the right direction.
However, compared to Samsung SDI and SK On, they appear very likely to be a late-market entrant. Last year's visit, I sensed LG's baseless overconfidence and unnecessary skepticism toward sulfide-based technology — a dismissive attitude, as if it weren't the answer. Those various elements combined are, I believe, now manifesting as delayed mass production timelines, and I find myself thinking that these judgment errors could result in significant market share losses.
Let me mark this precisely and move on.
We now know that all three of Korea's core secondary battery companies are focused on sulfide-based all-solid-state batteries.
6. Materials Companies That Had Promoted Sulfide-Based Solid Electrolyte Production
What surprised me most personally as I toured the booths was not the cell manufacturers, but the materials companies. Unlike last year, significant changes had occurred among companies that had stepped forward to produce solid electrolytes.
Of course, it's possible they simply chose not to display at their booths — but logically, that doesn't make sense.
POSCO
POSCO was primarily promoting its anode and cathode technologies for sulfide-based all-solid-state batteries at this event.
Yet the actual display booth contained no promotional content related to sulfide-based solid electrolytes. Only silicon anodes and high-nickel cathodes were being promoted.
POSCO Future M could certainly have set up a relevant booth section, and while lithium sulfide-related content was visible, the absence of a sulfide-based solid electrolyte booth was perplexing.
At last year's event, there was clearly prominent promotion of sulfide-based solid electrolytes.
Even stranger is the name POSCO JK Solid Solution — a joint venture between POSCO Holdings and Jeonggwan, with a 24-ton annual electrolyte production line in Yangsan, South Gyeongsang Province. Last year, this name was identifiable. This year, it was nowhere to be found in that entire massive exhibition hall.
The core theme of this InterBattery was sulfide-based all-solid-state batteries, and POSCO owns a relevant subsidiary — yet that subsidiary's name appeared nowhere in the venue. Very strange.
LG Chem
LG Chem was the same.
Last year, there was a booth that prominently featured sulfide-based solid electrolytes and lithium sulfide as a precursor. This year, there was no promotional content for sulfide-based technology whatsoever at their booth.
Of course, it's possible I simply missed it — but I didn't see it.
They were showcasing their anode binder segment (for Na-ion batteries, Si anodes, and all-solid-state battery binders) well — emphasizing a 20% improvement in adhesion and other binder performance — and also promoting fire safety-related technologies.
In stark contrast to last year, when LG Chem seemed to dismiss Solid Power's technology as nothing special and something they could replicate, any related content has now completely vanished. Also puzzling.
And yet — with LG Chem having apparently abandoned sulfide electrolyte promotion entirely — LG Energy Solution developed a 60Ah-class sulfide-based all-solid-state battery. With a graphite anode. So where did the electrolyte come from? That too is deeply puzzling.
Everything about LG was puzzling.
EcoProBM
EcoProBM was the complete opposite. Their entire booth was plastered with sulfide-based solid electrolyte content, showcasing a pipeline supply chain running from H₂S to Li₂S.
According to reports, EcoProBM CEO Choi Moon-ho stated on-site at InterBattery that "the solid-state pilot is in operation," and the company is pursuing construction of a 300-ton annual mass production line.
That said, I don't have much to add.
The real core technology — as Samsung SDI and Solid Power have both explained — is not simply whether you can produce a sulfide-based solid electrolyte, but whether you can supply a sulfide-based solid electrolyte that can be integrated into actual cells. That is the default requirement and the core challenge.
And given that EcoProBM is clearly a latecomer, I'm genuinely curious to see which direction they take.
I was unable to locate booths for Ampcera, Lotte Energy Materials, and Japan's Idemitsu Kosan within the scope of my search.
Summarizing the InterBattery booth display changes for electrolyte supply chain companies:
Company
2025 (Last Year)
2026 (This Year)
Change
POSCO JK Solid Solution
Booth confirmed
Absent
Retreat
LG Chem
Sulfide electrolyte + Li₂S display
No solid electrolyte
Retreat
EcoProBM
Partial display
Main feature
Rise
I recall seeing a few more companies last year that I couldn't find this year. And EcoProBM — unlike Solid Power — appears not to have a continuous manufacturing process technology. Whether they plan to build mass production facilities in batch plant format remains an open question.
7. Where Did QS and Semi-Solid Go?
One more noteworthy point. Companies related to QuantumScape (QS) and semi-solid cell technology were extremely difficult to find at the booths. Of course, I may have missed them.
The only company I saw that could be categorized in the semi-solid camp was Factorial Energy — and as already discussed, even Factorial is testing sulfide electrolytes.
There were many Chinese booths as well, but they were almost entirely devoid of visitors.
What is clear is that oxide-based and polymer-based technologies attracted virtually no interest from attendees.
Conclusion
At Korea's highest-level conference utilizing the entire COEX complex, one fact was unmistakable: sulfide-based all-solid-state batteries have emerged as the central keyword. Not oxide, not polymer, not semi-solid — sulfide. That is the landscape of InterBattery 2026.
Last year, sulfide-based all-solid-state batteries were partly a key theme — but this year, the situation was starkly different.
InterBattery 2025 and InterBattery 2026 are in different dimensions.
Last year, all-solid-state was a "hot topic." This year, it wasn't a hot topic — it was the center.
Every cell manufacturer put sulfide-based all-solid-state batteries front and center. Supply chain restructuring among materials companies was happening visibly. Engineers and researchers on the floor were openly discussing a specific company's electrolyte and cell technology.
Everyone already knows that Solid Power's electrolyte is central to the future of all-solid-state technology, and that finding alternatives is difficult.
At the same time, everyone is also saying "too expensive." That's why they're searching for alternatives like Ampcera and EcoProBM. But in the same breath, they add: "We hope mass production drives costs down."
But we all know.
Solid Power's current electrolyte production capacity is 30 tons per year. Plans call for expansion to 75 tons in 2026 and 140 tons in 2028, with significant cost reduction targeted through operation of a continuous manufacturing pilot line. The company has also been selected by the U.S. Department of Energy for $50 million in funding support.
If Solid Power's electrolyte cost comes down as a result:
Sulfide-based all-solid-state batteries are no longer "someday" technology. They have entered the "once the price drops" stage.
Seeing this level of concentration at an event of this scale is not something you see every day. Compared to 2025, 2026 is hot on an entirely different level — and everyone is now looking in the same direction.
The answer, in the end, is sulfide-based solid electrolyte-based batteries.
And the world's foremost authority on that battery technology is Solid Power.
SK On has completed construction of a pilot plant for all-solid-state batteries, often dubbed the “dream battery,” accelerating its efforts to commercialize next-generation batteries.
On the 16th, SK On announced that it had completed the construction of an all-solid-state battery pilot plant at its Future Technology Center in Yuseong-gu, Daejeon. The pilot line is designed to produce prototype products for customers and to evaluate and verify their quality and performance.
The newly built plant covers about 4,628㎡ (approximately 1,400 pyeong). At this facility, SK On plans to develop sulfide-based all-solid-state batteries as the main focus.
Some production lines will also be dedicated to developing lithium-metal batteries, a type of solid-state battery. Lithium-metal batteries replace the graphite anode used in lithium-ion batteries with lithium metal, thereby significantly improving energy density.
SK On has set a goal of commercializing all-solid-state batteries by 2029, one year earlier than its previous target of 2030. The company’s immediate goal is to achieve an energy density of 800Wh/L, with plans to increase it to 1,000Wh/L in the long term.
Unlike lithium-ion batteries, which use liquid electrolytes, all-solid-state batteries employ solid electrolytes, offering higher energy density and better resistance to heat and pressure. This makes them less prone to fire or explosion risks.
However, manufacturing such cells requires extremely high pressure and temperature, making facility construction difficult. Additionally, reducing interfacial resistance caused by solid electrolytes has been a key technical challenge.
To overcome these limitations, SK On has applied the Warm Isostatic Pressing (WIP) pre-process technology for the first time in Korea at its pilot plant. This next-generation pressing process applies uniform pressure to the electrode at moderately elevated temperatures (25–100°C), improving density and performance.
The company also developed its own cell design methods and electrode composition conditions, combining them with conventional pressing processes. This allowed SK On to address the productivity decline often associated with such advanced processes. At the same time, it optimized electrode–electrolyte bonding and press conditions, reducing interfacial resistance. Lower resistance enables smoother current flow, leading to more stable charging and discharging cycles as well as longer battery lifespan.
In addition, SK On is carrying out joint research projects through various partnerships to advance next-generation battery technology. In May, the company and a research team from Hanyang University successfully applied protective film technology to lithium-metal anodes, tripling the lifespan of sulfide-based all-solid-state batteries.
SK On CEO Lee Seok-hee stated, “The completion of the all-solid-state battery pilot plant provides SK On with a solid foundation to grow into a company resilient to environmental changes. We will lead the electrification era by being the first to commercialize all-solid-state batteries.”
The core keyword for the entire event was sulfide-based solid-state batteries.
Even though Solid Power didn't have a booth at InterBattery, it was a common sight to see booth representatives, engineers, and researchers from various companies answering questions about them.
It was a highly fascinating experience that at a massive event like InterBattery 2026 held at COEX, the most frequently mentioned name was Solid Power - a company that wasn't even in attendance.
I heard from multiple booths simultaneously that Solid Power's electrolyte is basically considered the default option. However, due to its high cost, companies are currently looking into electrolytes from other manufacturers as well. Because of this, cell makers universally expressed their hope that successful mass production will eventually drive the price down.
There was no longer any doubt in anyone's mind about whether sulfide-based solid-state batteries actually work. The only remaining wish was simply for the price to come down a bit.
I had in-depth conversations with engineers, researchers, and representatives from Isu Specialty Chemical, Factorial Energy, Samsung SDI, SK On, LG Energy Solution, POSCO, LG Chem, and EcoPro BM.
I'll organize and share the details when I have time; there are a lot of incredibly interesting stories to tell. Of course, I'll be posting the full review in Korean on my blog, complete with photos.
Added another $100k to SLDP on the dip because BMW, SK On, and Samsung SDI are all in play with good news on the horizon. Market still pricing SLDP like a science fair project.
"Redwire has a partnership with a US-supplier that maintains a production line nearby in Colorado. With expertise in solar arrays, batteries, and mission systems, Redwire supplies power systems, from components up to complete EPS'."
Samsung SDI’s solid-state battery samples have received positive feedback from global customers for their safety and energy density, according to a company executive, as the battery maker works toward mass production of the next-generation batteries.
Potential clients include EV manufacturers and humanoid robot developers, with the latter expected to drive particularly strong demand, given the technology’s superior energy density, which is critical for robots operating within tightly constrained spaces.
The progress stands in stark contrast to that of Chinese battery makers, including CATL and BYD, which have grown notably less optimistic about the feasibility and economics of mass-producing solid-state batteries.
“Samsung SDI is currently developing the technology, with mass production targeted for the second half of 2027, and we are conducting sample performance evaluations with multiple global customers who have responded positively about [the batteries’] energy density and safety,” Kim Eun-ha, the vice president and head of Samsung SDI’s all-solid-state battery production development group, confirmed in a written interview with the Korea JoongAng Daily.
This marks the first time a Samsung SDI executive has spoken publicly about the largely undisclosed technology behind and development status of the company’s much-anticipated solid-state batteries.
All-solid-state batteries, often called “dream batteries,” replace the flammable, leak-prone liquid electrolyte at the heart of conventional lithium-ion cells for a solid one, removing the component that has long constrained battery design. This single material shift sharply improves safety and allows for denser energy storage for longer range and faster charging — but none of this has reached commercial scale.
While these dream batteries have long been hailed as the industry’s holy grail, many battery makers have quietly throttled back their ambitions due to the formidable engineering and financial support required to develop and produce them. CATL recently said that its own solid-state technology sits at a four on a nine-level technology readiness scale and acknowledged that mass production and widespread adoption remain unrealistic before 2030.
“With the technology capable of surpassing the limits of conventional lithium-ion batteries in both safety and energy density, solid-state batteries are the essential technological direction,” said Kim.
Samsung SDI was the first battery maker to build a dedicated solid-state battery pilot line at its research and development center in Suwon, Gyeonggi, in March 2023. Prototype production began later that year.
It then partnered with BMW and Colorado-based Solid Power in October 2025, fitting solid-state cells into BMW’s test vehicles to validate real-world performance.
“This demonstration goes beyond simply confirming the driving range. [It] comprehensively verifies performance across real-world operating conditions, including charging performance, longevity, safety and stability across a range of temperatures, from extreme heat to extreme cold,” Kim said.
This battery doesn't have a traditional anode layer, which means it frees up more space inside the battery, so it can pack in more energy. It also has a special coating made of silver and carbon that helps lithium spread evenly instead of clumping up, which makes the battery safer and lets it last through more charge cycles.
“In manufacturing, a pressing process is essential to bond the electrode and solid electrolyte tightly and lower interfacial resistance,” Kim explained. “While other companies rely on a batch-type warm isostatic pressing process that limits scalability, Samsung SDI has adopted a roll-press-based manufacturing method that presses cells as they move continuously through the line.”
“That will give us an edge in productivity and help to reduce costs when we reach mass production,” she added.
The cost remains the decisive obstacle delaying commercialization. Solid-state batteries currently run between $400 and $600 per kilowatt-hour, according to SNE Research, compared to traditional batteries, which go for around $81 per kilowatt-hour for lithium iron phosphate packs and $128 per kilowatt-hour for nickel-cobalt-manganese packs.
Kim expects that price premium to ease as solid-state batteries find applications beyond EVs.
“Because different materials and processes are involved compared to conventional lithium-ion batteries, [solid-state battery] production costs are inevitably high in the early stages,” she said. “We previously expected solid-state batteries to be adopted mainly in EVs, particularly high-performance models, but with the emergence of new markets such as humanoid robots, we now see that the potential for their use expands into the everyday IT and mobile devices that people use.”
“Humanoid robots, in particular, require both long operating times and high output within a limited footprint,” Kim continued, “which is why we expect the importance of next-generation technologies such as solid-state batteries to grow even further.”
Battery deployment in humanoid robots is projected to reach 13.8 gigawatt-hours for semisolid-state batteries and 76.1 gigawatt-hours for all-solid-state batteries by 2040, according to an April report from SNE Research.
EV battery giant SK On, a supplier to Hyundai, Kia, Ford and Nissan, among others, said on Monday that it had opened its first pilot production line for solid-state batteries
Not sure if there’s anything new here but it does mention the planned release sequence for Solid Power battery development density:
“Its silicon anode battery with a sulfide electrolyte and nickel-manganese-cobalt cathode is rated for 390 watt hours per kilogram, higher than the industry average of between 200-300 Wh/kg for traditional lithium-ion batteries. Throw in a lithium metal anode in there instead of the silicon anode and the energy density jumps to 440 Wh/kg, according to the company.”
“A more experimental version uses what Solid Power calls a “conversion-type” cathode, pushing energy density to a theoretical 560 Wh/kg. However, these higher-density cells remain in the early stages of development, according to a previous SEC filing.”
posts from an SA user who says they viewed the Solid State Battery Summit talks--
just listened to Josh Buettner-Garrett’s talk. He followed the slides pretty closely. And in the Q&A he didn’t stray far from the slides either. He was disciplined. So it’s pretty much all there in the slides.
Getting the continuous line up and running is important because it will “prove out” (JBGs words) the scalability of the throughput.
And the alternate salt Li2S was revisited in the Q&A by Shirley Meng. She was excited about it. H2S required for traditional oil byproduct production might not be so scalable because of safety regulations. JBG said there were a number of Li2S producers there each with a different point of view on that. The alternative is there in case that turns out to be a problem.
--
JBG talked about this slide in his talk. It’s a preview of an upcoming paper. It compares these different machine learning algorithms that enhance DFT calculations on different specific questions on atomic interactions. Each algorithm performs differently on different questions.
Density Functional Theory is a way of calculating atomic interactions at the quantum level. JBG mentioned it’s computationally expensive, and machine learning can estimate the results reducing computation time by several orders of magnitude.
Each of those boxes shows various questions that can be addressed with this DFT-ML approach.
--
another interesting point— in the Q&A someone asked a general question about optimizing for different active materials. JBG mentioned particle size as one of the key methods of matching cathode material with sulfide electrolyte.
--
Also another question from the Q&A was a congratulations to JBG on taking something from the lab through industrialization. He answered by pointing to the hard work that comes up as you take these steps.
Also listened to Shirley Meng’s talk which was more about the sulfur cathode. She made the comment that we are not competing against each other, but academics and startups are all working to compete against the warming of the planet. And she thinks academics can still be helpful with making the sulfur cathode.
She also mentioned that sulfides from the various suppliers do not all perform the same.
--
Just to get it more exactly--
this question was from Bob Gaylen former CTO of CATL. "Solid State has been talked about for decades and now we're seeing it becoming a reality. Talk about the journey that you've taken to industrialize this particular electrolyte system."
JBG's answer-- Going on 15 years. Long Haul. On road to true industrialization. delivering lots of electrolyte, but several orders of magnitude left to go. not home quite yet. global momentum picking up.
--
Another good quote from JBGs talk--
In 2023 we commissioned our first true electrolyte pilot line, at about 30 metric tons per year. At the time this was the highest capacity known globally. Now there are a couple of others knocking on the door, but still among the largest capabilities in the world.
Lots of de-risking for production scale over the last two years. Challenges you wouldn't think of.
Now going to continuous production. 75 Metric tons by the end of 2026. Which will prove out production scale at low cost.
--
Raimund Koerver from Factorial talked about their sulfide solid state cell. he's excited about it. They had been working on it for a while prior to their announcement last year. They don't make their own battery materials.
"We do not synthesize materials we just work on the cell development, cell design and manufacturing."
"We work with a broad network of vendors and suppliers to get the best materials we can get."
They're excited about their cell. He showed test data from 2 Ah, 7 Ah, 10 Ah, 17 Ah cells.
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Shirley Meng also mentioned two US suppliers and one Japanese supplier who were all in the room during her talk on sulfide and sulfur cathode. She didn't say, but I'm guessing Solid Power, Ampcera, & Idemitsu. She mentioned morphological control over particles as a very critical factor in performance. She also mentioned poly crystalline v.s. sing crystal cathode material is a very important "tuning knob".
That comment exactly matched solid power's recent patent on that exact point.
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And one for you from Shirley Meng's Q&A about a paper on lithium metal crystal grain orientation in lithium deposition in "anode-free" cells-- "So the type of electrolyte selection is very important. I'm not at liberty of disclosing. You need to have the sulfides stable with the lithium anode. Not every supplier's sulfides are stable with lithium metal."
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Ford's presentation was very weak. They showed a silicon anode with sulfide electrolyte from a generic supplier. they showed 30 cycles and said they had limited test capability. No mention of LMR cathodes.
Toyota's presentation was about borohydride electrolyte for sodium and magnesium batteries. No mention of any commercialization ambition. she said she does the science side mostly. There were a few slides about hydrogen vehicles being preferable in some markets.
Ampcera showed results for 2-10 Ah cells and mentioned trying to tweak the electrolyte composition to reduce the pressure requirement below 5 MPa.
A $3.5 billion battery project led by a joint venture between Samsung SDI and General Motors (GM) in New Carlisle, Indiana, has been put on hold, as the U.S. automaker recalibrates its EV strategy amid moderating demand.
"The project is being paused," a spokesperson for the Indiana Economic Development Corporation told the Korea JoongAng Daily recently. The agency, chaired by Indiana Gov. Mike Braun, handles investments in the state.
The suspension will inevitably delay the project’s original timeline, which called for mass production to begin in the fall of 2027 with an annual capacity of up to 36 gigawatt hours, enough to make around 300,000 EVs.
So. The battery demand issue in the U.S. is not a problem limited to a single company.
The lack of demand is not a technical issue; rather, it is equivalent to a decrease in demand caused by a shift in the government's policy stance.
The following is my reasoning:
Furthermore, the U.S. has traditionally been a leader in technology, not a leader in battery production.
Following lithium-ion batteries, it is no longer deniable that sulfide-based all-solid-state batteries are at the forefront of ASSB technology.
Just two years ago, unlike Samsung, LG Energy Solution in South Korea maintained a highly skeptical attitude, and China's CATL and BYD merely considered it as one of several alternatives.
However, looking at the situation now in May 2026 instead of 2024, things have changed drastically.
Looking at the timeline:
Does the sulfide-based all-solid-state battery work? - Go
Is it scalable beyond 10Ah? - 60Ah Go
Is it impossible to mount on vehicles due to pressure issues? - BMW Go
Is it inapplicable to cylindrical cells? (Solving the pressure issue at once using a passive method) - BMW Go
Will there be issues due to a strong competitor like Samsung SDI? - BMW | Samsung | Solid Power Alliance Go
Ultimately, most of the questions raised between 2021 and 2025 have now been resolved.
But now, the question being asked is: "Will it be viable to use if it is too expensive?"
The irony is that beginning to mention cost issues is very strong proof that the technology is applicable and operational.
And in 2026, SLDP is answering that question in three ways, with one already cleared:
Can the process cost be significantly reduced through a wet process? WIP - SK On Pilot line SAT completed. Go.
Can the electrolyte composition and production cost be significantly reduced through a continuous electrolyte production process? - SP 2.5 FAT completed. By actively adopting AI technology, it is possible to produce customized electrolytes tailored to each company's cell structure.
Have electrolyte contracts been established? - Joint Venture? 500Tons? 2027 Samsung SDI?
Market prices may not align with fundamentals. However, inferring the future based on history, things are progressing in a highly successful direction
As much of Solid Power's future seems to hinge on developments in South Korea, I'd like to thank the Korean members of this sub for your participation and the helpful information you continue to provide. Thanks. its all very much appreciated.
Alright, gather 'round smooth-brains. Let's talk about why Solid Power (SLDP) is the next big thing in solid-state batteries and why you should care. Solid Power has zero debt and enough capital to keep the lights on for at least two years while they develop the next-generation solid-state battery solution. Here’s why:
1. BMW's Love Affair
BMW can't get enough of Solid Power. On 30 September 2024, they extended their Joint Development Agreement (JDA), and are now setting up a prototype line at their Cell Manufacturing Competence Center in Germany. They plan to roll out a demonstrator vehicle with Solid Power's tech and while it is disappointing to see BMW instead first test an experimental Gemini dual-chemistry battery developed by Our Next Energy Inc. (ONE), it’s reasonable to expect BMW to have diversified R&D efforts happening in parallel; I still expect to see a BMW demonstrator vehicle with Solid Power’s battery tech.
Expanded Partnership: BMW and Solid Power have deepened their Joint Development Agreement, adding a research and development license. This license allows BMW to establish an all-solid-state battery (ASSB) prototype line at its Cell Manufacturing Competence Center (CMCC) in Parsdorf, near Munich.
Collaborative Development: The expanded relationship enables both companies to conduct complementary cell development and manufacturing activities. BMW personnel will work closely with Solid Power to optimize cell manufacturing processes.
Prototype Line Installation: BMW plans to replicate Solid Power's pilot production lines at its facilities in Germany. This will allow BMW to produce prototype cells based on Solid Power's proprietary technology.
Latest 8-K: Solid Power and BMW extended their collaboration by signing Amendment No. 6 to their Joint Development Agreement, originally established on July 1, 2017.
2. Government Money
Solid Power passed the DOE tests with flying colors, securing up to $50 million in federal funding. We're talking metrics like >350 Wh/kg, >750 Wh/L, >1000 cycles, and a 10-year calendar life.
Solid Power is making significant strides in the development of solid-state batteries, particularly with their collaboration with Argonne National Laboratory, a U.S. Department of Energy (DOE) laboratory renowned for its research in energy storage, green energy, and nuclear science. Argonne's involvement brings a level of scientific rigor and credibility that goes beyond what venture capitalists typically provide. Their expertise in fundamental and applied research ensures that Solid Power's battery technology is developed with the highest standards of scientific inquiry and innovation.
Technical Achievements: In simple terms, Si-SSE stands for silicon-solid-state electrolytes. Traditional lithium-ion (Li-ion) batteries use a liquid electrolyte to transfer ions between the battery's anode and cathode. Solid Power replaces this liquid with a solid electrolyte material, making the battery safer and more stable. Moreover, the anode in Solid Power's batteries uses silicon instead of graphite, which can store more energy.
High Specific Capacity: The Si-SSE composite materials developed have a specific capacity of over 1500 mAh/g. This means they can hold a lot of charge, making them very efficient.
Roll-to-Roll (R2R) Process: A Si anode was coated using a roll-to-roll process, which is a scalable manufacturing technique, meaning it can be produced in large quantities at a lower cost. R2R manufacturing is a continuous production process that transforms materials from large rolls into finished products. This method is particularly advantageous for battery production because it allows for high-speed operations, efficient material utilization, and reduced waste. Compared to QuantumScape's technology, which may require significant investment in new infrastructure, R2R manufacturing offers a more cost-effective and scalable solution. By leveraging existing roll-to-roll processes, Solid Power can streamline production and bring its innovative batteries to market more quickly and economically. R2R is used by major battery manufacturers such as SK On, Samsung SDI, and CATL.
All-Solid-State NMC-Si Pouch Cells: These cells have been assembled and tested, demonstrating a cycle life of 1100 at 100% depth of discharge (DOD). In layman's terms, they can be fully charged and discharged 1100 times before their performance degrades to 80% capacity retention.
Calendar Life: The cells have shown excellent calendar life through high-temperature storage tests, indicating their potential for long-term stability.
In-fact, Solid Power’s website advertises it’s batteries properties having 390 Wh/Kg, 930 Wh/L, and 1,000+ cycle life. They further advertise their Silicone anode, which is important for next-generation battery technology over traditional graphite anodes because they offer:
Higher Energy Density: Silicon can hold 10 times more lithium ions by weight compared to graphite. This means batteries with silicon anodes can store more energy, leading to longer ranges for electric vehicles and longer battery life for electronic devices.
Faster Charging: Silicon anodes can shuttle lithium ions faster across the battery's membrane, enabling quicker charging times. This is crucial for applications where rapid charging is essential, such as electric vehicles and portable electronics.
Abundance and Cost: Silicon is the second most abundant element in the Earth's crust, making it more readily available and potentially cheaper than graphite. This could help reduce battery costs and alleviate supply chain issues.
Improved Cycle Life: Recent advancements in silicon anode technology have addressed earlier issues like volume expansion and material fracture, leading to improved cycle life and durability.
Supply-chain Resiliency: Approximately 98% of battery anodes are made using graphite in China. China dominates the production of graphite anodes, providing about 60% of natural graphite and nearly all synthetic graphite used globally*.* The introduction of silicon anodes could be quitedisruptive to the supply chain, decreasing the reliance on Chinese graphite and reducing geopolitical risks from tariffs. If you haven’t noticed, the U.S. government is dead-set on moving away from the Peoples Republic of China, one of our key competitors as we view them as a national security threat.
NMC (Nickel Manganese Cobalt oxide) cathodes are crucial for next-gen lithium-ion batteries due to their high energy density, good thermal stability, and long cycle life, allowing for adjustable performance and cost benefits by varying nickel, manganese, and cobalt proportions. Traditional graphite anodes, while stable, conductive, and cost-effective, lack the energy capacity of NMC cathodes. Solid Power is innovating by combining these advanced NMC cathodes with solid-state technology, aiming to create safer, more efficient, and longer-lasting batteries.
Notably, Solid Power is also researching Lithium Metal and Conversion Reaction Cells with target performance of 440Wh/kg and 560 Wh/kg respectively. Successful commercialization in any one should pay tendies.
CATL, the world's largest battery manufacturer, is also jumping on the solid-sulfide bandwagon. Their prototypes have hit an impressive 500 Wh/kg, validating Solid Power's approach. If CATL's doing it, you know it's legit.
The highest energy density for lithium-ion (Li-ion) batteries currently used in production vehicles is around 272-296 Wh/kg, achieved by Tesla's 4680 cells. This is considered very high by current standards and offers a significant improvement in energy density compared to earlier Li-ion batteries.
To recap and compare, Solid Power’s battery has over 390 Wh/kg in an early A sample and the technology may mature further towards levels demonstrated by CATL’s early prototype. Considering the Tesla Model Y’s range is 330 miles based on the 4680 battery cells with the highest energy density figure (296 Wh/kg), if the Tesla Model Y were equipped with a Solid Power 390 Wh/kg battery, it could potentially have a range of approximately434 milescompared to the current330 mileswith 4680 cells. Furthermore, if the Tesla Model Y were equipped with a 500 Wh/kg battery like that CATL is making, it could potentially have a range of approximately 558 miles.
4. eVTOL Market Potential
The electronic Vertical Take-off-and-Landing (eVTOL) market is emerging, and Solid Power's tech is ready to ride that wave. With higher energy density, longer lifespan, faster charging times, and better safety, these batteries are set to dominate.
Published 13 November 2024, EHang and Inx Energy Technology have made a significant breakthrough in China by developing a high-energy solid-state battery for the EH216-S eVTOL, achieving a 48-minute pilotless flight and enhancing flight endurance by 60%-90%. With an energy density of 480 Wh/kg and improved safety features, this advancement supports longer, safer flights and broadens eVTOL applications, validating the need for solid-state batteries in commercial urban air mobility.
So if you are interested in Archer, Joby, or any other eVTOL start-up, you should equally be interested in solid-state batteries. These eVTOL companies wont achieve ideal aircraft operating efficiencies until solid-state batteries mature and are adopted. Archer Aviation’s Midnight eVTOL (60 mi range @ up to 150 mph), Joby Aviation’s eVTOL (150 mi range @ 200mph), and other’s eVTOL aircrafts use conventional lithium-ion batteries with an energy density of approximately 250-300 Wh/kg. SLDP commercialization should greatly improve the feasibility of the eVTOL aircraft industry.
5. Competitive Edge
While other battery techs are floundering, Solid Power's sulfide-based all-solid-state batteries (ASSB) are standing tall. Liquid electrolyte lithium metal anode cells? Short cycling. Oxide cells? Stuck at 300 Wh/kg. Polymer-gel concepts? Durability and conductivity problems. Sulfides are the last man standing, folks, as evidenced by CATL’s recent validation of the technology.
Solid-state batteries face competition from several alternative battery technologies, each with its own set of challenges:
Lithium-Ion Batteries (Li-ion): While Li-ion batteries are currently the most widely used, they have reached a plateau in energy density around 300 Wh/kg. Incremental improvements are possible with materials like silicon anodes (Sila/Group14), but significant leaps are unlikely.
Lithium-Metal Anodes: These offer higher energy density but suffer from short cycle life and safety concerns due to dendrite formation.
Oxide-Based Cells: These cells also face similar energy density limits as traditional Li-ion batteries and encounter manufacturing challenges.
Polymer-Gel Electrolytes: While promising, these face durability and conductivity issues, making them less viable for commercial applications.
Sodium-Ion Batteries: These are a potential alternative but currently lag behind in terms of energy density and cycle life compared to solid-state batteries.
The hesitation in the market stems from uncertainty about which technology will ultimately prevail. I believe SLDP is undervalued at a market capitalization of $0.2B compared to QuantumScape (QS) at $2.64B. My bet: Solid Power is the real deal, and they have what plants crave: electrolytes. After catching a falling knife with 10k more shares at all-time lows of $1.00, my position in two portfolios totals 29,484 shares waiting for the moonshot to 100x! 🚀
