What’s the story: two investments in opposite directions in the same month
On August 12-13, 2026, news came out in quick succession that Solivis, a company specializing in sulfide solid electrolytes, had raised 23 billion won in a Series C, and that Cosmos Lab, an aqueous zinc-halogen battery company, had raised 22 billion won in a Series A. Both companies target ‘what comes after lithium-ion’, but one chose to push up energy density (solid electrolytes), while the other put non-flammability and cost first (aqueous zinc). This article compares the principles and bottlenecks of the two technologies and, from a patent perspective, sets out which layers of rights should be tracked in each.
Starting with the industry picture, Cosmos Lab announced on August 12, 2026 that it had raised a 22-billion-won Series A from domestic and overseas financial and strategic investors, including Smilegate Investment. The company is developing cells that use a water-based non-flammable electrolyte and zinc and halogen-based materials for AI data centers and grid ESS, and said it aims for mass production in 2027 through joint development with SoftBank. The next day, August 13, Solivis announced that it had closed a 23-billion-won Series C with participation from OpenWater Investment and others, bringing its cumulative investment since its founding in 2020 to 65.2 billion won. Solivis was reported to be operating a solid-electrolyte plant with an annual capacity of 36 tons in Hoengseong, Gangwon Province.
The tension lies in the fact that the two pools of money bet on different answers to the same question. There is still no single solution that addresses both the fire risk and the energy-density limit of lithium-ion, and investors are betting on which of ‘higher’ or ‘safer and cheaper’ will open the market first. This article answers two questions: what do the two technologies change and what are their bottlenecks, and which patents should IP staff look at first in each camp.
Basic principle: what materials and chemistry change
A solid electrolyte replaces the liquid organic electrolyte with a solid (sulfide, oxide, polymer, etc.) to structurally reduce leakage and ignition risk, with the goal of raising energy density in combination with a lithium-metal anode. Sulfides are regarded as a key material because of their high ionic conductivity and excellent formability. However, the resistance of the solid-solid interface is higher than with a liquid electrolyte, and lowering it is the key task for commercialization.
Source: reconstructed by the editorial team from the original comparison table and Cosmos Lab's technology description in Money Today (2026-08-12)
By analogy, a solid-electrolyte battery is a mechanical watch with precisely meshed parts to eliminate gaps between components, while an aqueous zinc battery is a sturdy water-filled container. The watch is small and precise but stops if its parts are even slightly misaligned (poor interfacial contact), while the container does not catch fire and is cheap but has a limit on how much it can hold in the same volume (energy density).
Aqueous zinc secondary batteries take the opposite approach. Because they use a water-based electrolyte instead of an organic one, fire risk is low from the outset and cost is low, but energy density is lower than lithium-ion, making them suited first to uses such as ESS where weight matters less. Cosmos Lab’s approach is a zinc-halogen type using zinc and halogens (bromine-based), and, unlike conventional zinc-bromine flow batteries that need external electrolyte tanks and circulation pumps, it promotes an integrated cell structure. When it unveiled the technology in October 2025, the company presented an energy density of about 170Wh/kg at the cell level and a 50Ah prismatic form factor.
Comparison: the goals and bottlenecks of the two paths
| Item | Solid electrolyte (lithium-based) | Aqueous zinc secondary battery |
|---|---|---|
| Target energy density | High | Medium to low (Cosmos Lab presents about 170Wh/kg at cell level) |
| Fire safety | Improved vs. liquid | Inherently excellent (water-based non-flammable electrolyte) |
| Cost | High | Low |
| Main applications | EVs, high-energy-density applications | ESS, stationary storage, AI data centers |
| Commercialization bottleneck | Interfacial resistance, mass-production yield, mass production of solid electrolytes | Cycle life, self-discharge, halogen fixation |
Source: compiled by the editorial team from the original comparison table, supplemented with figures Cosmos Lab disclosed to The Asia Business Daily (2025-10-10)
What this table says: The two technologies trade energy density against safety and cost. However, the roughly 170Wh/kg at cell level presented by Cosmos Lab is a company figure, and without confirmed third-party verification it is safer to read it only as an upper-end example of the ‘medium to low’ range.
| Item | Solivis | Cosmos Lab |
|---|---|---|
| Announcement date | 2026-08-13 | 2026-08-12 |
| Round and size | Series C, 23 billion won | Series A, 22 billion won |
| Technology | Sulfide solid-electrolyte materials | Aqueous zinc-halogen cells |
| Value-chain position | Material (electrolyte) supply | Cells and systems |
| Production | Hoengseong plant, 36 t/yr in operation (reported) | Joint development with SoftBank, mass production targeted for 2027 |
| Cumulative investment | 65.2 billion won (since founding in 2020) | Not confirmed from public sources |
Source: compiled by the editorial team from Newspim and ZDNet Korea (2026-08-13) and Money Today and Asia Economy (2026-08-12)
What this table says: The investment sizes of 23 billion won and 22 billion won are similar, but one is a materials company selling to solid-state cell makers and the other is a company making the final cell. Even under the same label of ‘next-generation battery investment’, the point where revenue arises and the point where risk sits differ.
Here we add one insight not in the original. The two investments are more accurately read as a difference in ‘choice of value-chain position’ than as ‘technology competition’. Solivis chose a position from which it can supply sulfide electrolytes whichever cell maker wins the solid-state race, while Cosmos Lab ties a specific demand source, AI data centers, to a large partner (SoftBank) and competes with the cell itself. The former is more exposed to the growth of the solid-state market as a whole, and the latter to the mass-production success of specific projects.
Patent perspective: interface-coating claims and early-stage aqueous zinc
In the solid-electrolyte field, there is a clear tendency for composition patents to be filed in fine segments by sulfide, oxide and polymer families. Many claims have been granted on the composition of coating layers to lower interfacial resistance (for example, buffer layers such as LiNbO₃) or on pressing conditions, which fits a typical portfolio strategy of treating one composition as the core technology and densely patenting its surroundings implementation by implementation.
A representative example is Toyota’s US8557445B2 (title “All-solid-state battery”, applicant Toyota Motor Corp). Bibliographic data: priority date April 28, 2009, filing date April 27, 2010, grant date October 15, 2013; its legal status on Google Patents is Active, with an anticipated expiration date of September 9, 2031. The publication is US20100273062A1.
Gist of the claims (restated): The independent claim claims an all-solid-state battery in which a first sulfide solid electrolyte substantially free of cross-linking chalcogen (a structure in which a sulfur atom bridges two phosphorus atoms) (e.g., Li₃PS₄) is placed in the cathode layer, and a second sulfide solid electrolyte having cross-linking chalcogen (e.g., Li₇P₃S₁₁) is placed in the solid electrolyte layer between the cathode and anode. The design confines the highly reactive structure to the middle layer and places a stable composition at the cathode interface to suppress decomposition. A configuration in which the cathode active material is coated with a lithium-ion-conductive oxide such as LiNbO₃ is recited as a limitation at the dependent-claim level.
Source: reconstructed by the editorial team from the claims of US8557445B2
- Nature of the scope of rights: The claimed subject is the battery configuration, not the electrolyte material. The direct risk of infringement therefore lies with cell makers, while electrolyte material suppliers may become subjects of indirect review depending on whether the materials they supply are used in this layer configuration.
- Design-around options: Using the same type of sulfide electrolyte in the cathode layer and the electrolyte layer (for example, a single composition without cross-linking structure), or using a composition system such as argyrodites that differs from the claim’s ‘presence or absence of cross-linking chalcogen’ distinction, may leave room to keep distance from the claim elements.
- Design-around scenario (counterargument): However, the expression ‘substantially does not have’ is a matter of degree, so which side a composition with a small residual cross-linking structure falls on may be disputed depending on the analytical conditions. Conversely, from the patentee’s side, the scope of rights may be interpreted narrowly when compared with the flood of sulfide composition literature since 2009.
Aqueous zinc has been regarded as an early-stage technology with relatively low patent density, and securing claims first on electrolyte additives, suppression of zinc dendrites (branch-shaped metal deposits) and halogen-fixation structures is likely to be a factor that creates a gap with latecomers. Cosmos Lab said in September 2023 that it had registered patents titled ‘zinc-bromine supercapattery’ and ‘membrane electrode assembly and zinc-bromine supercapattery including the same’, but the registration numbers and claim scope could not be confirmed from published patent information in this article. Patents in the name of Solivis likewise could not be verified at the level of numbers and are left as tracking points.
Limits and outlook
Unless the interfacial-resistance problem is solved, solid electrolytes may be slow to secure cost competitiveness in mass production, and aqueous zinc batteries are likely to remain centered on ESS because of their energy-density limit. For now it is more reasonable to see the two technologies not as competitors but as parallel development paths that split by application.
The optimistic outlook is that solid-state cell mass production gets fully under way around 2027, raising demand for sulfide electrolytes, and that the safety requirements of AI data centers open the first large market for non-flammable aqueous batteries. There is also an opposite scenario. When Cosmos Lab unveiled its technology in October 2025 it presented a target of full-scale production in 2026, but in its August 2026 announcement it stated a mass-production target of 2027, showing that mass-production schedules for new chemistries can slip. If solid-state cell makers’ mass production is delayed, the utilization of electrolyte plants with annual capacities of tens of tons may also fall.
The strategic alternative is to build a portfolio that divides the two camps by ‘value-chain position’ rather than ‘application’. Evaluating materials companies on their supply track record and composition patents tailored to multiple cell makers, and cell companies on certification with specific customers and cell-structure patents, as their respective core assets reveals risk more accurately.
Practical action: Planning and IP staff seeking to procure or supply sulfide solid electrolytes should check whether the sulfide compositions used in the cathode layer and electrolyte layer of the target cell have cross-linking structures, and prepare an element-by-element comparison chart against the claims of US8557445B2 before signing a contract.
Items requiring verification
- The registration numbers and claim scope of Cosmos Lab’s registered patents (‘zinc-bromine supercapattery’, etc.)
- The registration status of solid-electrolyte composition and manufacturing patents in the name of Solivis
- The test conditions and any third-party verification of Cosmos Lab’s figure of about 170Wh/kg at cell level
- Published cycle-life and self-discharge data for Cosmos Lab cells
- The operating basis of the 36 t/yr capacity at Solivis’s Hoengseong plant (whether it includes trial production)
Sources
- Newspim, Solivis attracts 23 billion won Series C investment (2026-08-13)
- ZDNet Korea, ‘Solid electrolyte’ company Solivis attracts Series C investment… full-scale global push (2026-08-13)
- Money Today, ‘Non-burning battery’ for data centers and ESS… Cosmos Lab attracts 22 billion won (2026-08-12)
- Asia Economy, Cosmos Lab attracts 22 billion won Series A… accelerating mass production of ‘non-flammable’ non-lithium batteries (2026-08-12)
- Seoul Economic Daily, SoftBank Partners with Korean Startup Cosmos Lab for Zinc Battery Production (2026-05-04)
- The Asia Business Daily, Cosmos Lab Officially Unveils “100% Non-Flammable” Aqueous Zinc-Halogen Battery for ESS (2025-10-10)
- Money Today, Cosmos Lab registers patents for core technology of next-generation ‘water battery’ that solves fire problem (2023-09-25)
- Google Patents, US8557445B2 – All-solid-state battery (Toyota Motor Corp)