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Lotte Energy Materials (KOSPI: 020150): Sulfide Solid Electrolyte Materials for EV Batteries
The copper-foil maker turned solid electrolyte hopeful, betting a 2018 R&D bet finally pays off just as the industry needs the tonnage.
Who they are
Lotte Energy Materials is the battery-materials arm of the Lotte group, best known until recently as one of the world's larger makers of electrolytic copper foil — the ultra-thin film that carries current inside a lithium-ion battery's anode. Rebranded from Iljin Materials after Lotte Chemical acquired a controlling stake, the company has spent since 2018 quietly building out a second business: sulfide-based solid electrolyte, developed using both dry and wet synthesis methods to hit high ionic conductivity at nanoscale particle sizes.
What they do
The company's core, revenue-generating business is still copper foil for conventional EV and consumer-electronics batteries. Layered on top is its solid electrolyte push: a 70-tonne-per-year pilot line at its Iksan Plant 2 in Jeollabuk-do, completed with a ₩15 billion investment, and a roadmap to a 1,200 t/yr commercial-scale facility by 2026 ahead of a targeted 2027 production ramp. In June 2026, the company won national "NET" new-technology certification for a proprietary micronization process — using a ketone-based dispersant to grind sulfide electrolyte particles down to the sub-micron level without degrading crystal structure or ionic conductivity, a step aimed at improving yield and cutting production cost.
How they make money
Copper foil remains the overwhelming majority of revenue today, sold into conventional lithium-ion battery supply chains — a business exposed to the same EV-demand slowdown pressuring the whole sector. Solid electrolyte is still a pre-commercial R&D and sampling line, not yet a revenue contributor; the company has said it's evaluating a scale-up to roughly 1 GWh-equivalent capacity in cooperation with a battery-maker partner, but no named supply contract has been publicly disclosed.
Where it sits in the value chain
Lotte Energy Materials sits in Solid Electrolyte Materials, alongside EcoPro BM and ISU Specialty Chemical, as one of Korea's handful of sulfide-electrolyte pilot producers positioning ahead of actual cell-maker demand. That's typical for this stage of the chain — materials suppliers routinely build capacity before the exact order size is locked in, essentially betting that Samsung SDI's 2027 and LG Energy Solution's 2030 targets will actually hold.
The bigger trend
Lotte Energy Materials' solid electrolyte story is a good illustration of how the whole Korean materials tier is positioning: pilot line first (70 t/yr since 2024), a commercial-scale bet layered on top (1,200 t/yr by 2026) before a named large customer is locked in, and a steady stream of process patents and government certifications (like the June 2026 NET award) used to signal technical credibility to potential cell-maker partners. None of that guarantees a contract — sulfide electrolyte demand still depends entirely on Samsung SDI, LG Energy Solution, and SK On actually hitting their 2027–2030 mass-production windows.
What to watch
- Whether the planned 1 GWh-scale expansion, described as under evaluation with a battery-maker partner, converts into a named supply agreement.
- Whether the 1,200 t/yr commercial facility actually comes online on the stated 2026–2027 timeline, or slips as similar first-of-a-kind chemical plants often do.
- How much the copper-foil business — still the vast majority of revenue — recovers as EV demand growth normalizes, since that's what funds the solid electrolyte R&D in the meantime.
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FAQ
Is Lotte Energy Materials mainly a solid-state battery company?
Not yet in revenue terms. Its core business today is electrolytic copper foil for conventional lithium-ion batteries. Solid electrolyte is a fast-growing R&D and pilot-scale program layered on top, not yet a meaningful revenue line.
How much solid electrolyte can Lotte Energy Materials currently produce?
Its pilot line at Iksan Plant 2 in South Korea runs at up to 70 tonnes per year. The company has laid out plans for a larger, roughly 1,200 t/yr commercial facility targeting a 2026–2027 timeframe, and says it's evaluating a further scale-up toward 1 GWh-equivalent capacity with a battery-maker partner.
Does Lotte Energy Materials have a named cell-maker customer for solid electrolyte?
No specific supply agreement has been publicly disclosed as of mid-2026. The company has said it's in discussions with potential battery-maker partners on capacity expansion, but hasn't named a customer or contract.