From patents to research and commercialization activities

The first part of this article showed that lithium-sulfur batteries continue to be patented intensively, but that the patent landscape is strongly shaped by China and a small number of international actors. Europe has so far appeared only selectively in the global IP landscape.

This second part looks at two further levels: first, companies and start-ups seeking to commercialize or prepare Li-S batteries for market entry; and second, publicly funded research projects in Germany and Europe. This makes it possible to assess whether, beyond the patent landscape, research and corporate activity also point toward application, cell integration and industrialization — and what role Europe plays in this process.

Industrialization activities and start-ups

Lithium-sulfur batteries are primarily positioned around three value propositions: higher gravimetric energy density or lower weight, potentially lower material costs, and reduced dependence on nickel, cobalt and graphite.

Geographically, commercialization is not concentrated in one region but distributed globally, as Figure 1 shows based on selected company locations of active Li-S actors. The United States is strongly represented by start-ups and applications in defense, space and other specialized markets, including Lyten, Zeta Energy, Solidion, NexTech, Sion Power and Conamix. In Europe, relevant material and cell approaches can be found at Theion, Alteva and Gelion Europe/Oxlid; in addition, Lyten has acquired Northvolt assets in Sweden and Poland. Asia remains relevant through CATL, LG Energy Solution, Samsung SDI, SVOLT and Chinese actors such as General New Energy (GNE). Publicly, however, Li-S appears there more as part of broader next-generation battery portfolios than as a dominant short-term commercialization pathway.

Overall, the company landscape is heterogeneous. Some actors mainly communicate material, coin-cell or early pouch-cell results, while others already address concrete applications in unmanned aerial vehicles, defense, space or stationary storage systems. A broadly available automotive-grade Li-S cell for the mass market is currently not visible. An overview of individual company activities is provided in Table 1.

Lyten currently appears to be the company moving furthest toward industrialization. It communicates deliveries for UAV applications and is building up a manufacturing base in parallel. This includes a planned Li-S gigafactory in Nevada with up to 10 GWh of annual capacity, as well as acquired Northvolt assets in Europe, including battery energy storage system manufacturing in Poland and cell manufacturing and R&D capacities in Sweden. At the same time, it is clear that qualification for automotive applications requires longer timeframes. In the near term, markets with shorter validation cycles are therefore more likely to be in focus, including UAVs, defense, data centers and other specialized applications.

For the passenger car market, the cooperation between Zeta Energy and Stellantis is particularly relevant. Li-S is explicitly addressed there as a future technology for electric vehicles, but with a timeframe of around 2030. This suggests that, in the automotive sector, Li-S should be understood more as a medium-term option after further pre-series development, rather than as an immediate production chemistry for the next two to three years.

In addition, a larger group of companies is pursuing technically active but less industrialized pathways. Solidion, Gelion, Theion, Alteva, Conamix, NexTech and GNE address different parts of the value chain — from sulfur cathode materials and electrolytes to cell concepts and defense and space applications. The communicated performance indicators range from sulfur-based specific capacities and several hundred Wh/kg to roadmap targets of 500 to 1,000 Wh/kg at cell level. These figures are only comparable to a limited extent, as they may refer to different levels: active material, coin cell, pouch cell, cell level or strategic target values.

The large Asian cell manufacturers play a different role in this landscape. For CATL, LG Energy Solution and Samsung SDI, Li-S currently appears more as a strategic research or future option than as a short-term product program. LG Energy Solution demonstrated a sulfur cathode in an all-solid-state architecture in 2026, while Samsung SDI names Li-S as a development field for urban air mobility and lightweight applications, among others. CATL has activities and intellectual property around Li-S, but publicly communicates high energy densities more strongly through alternative approaches such as the condensed-matter battery.

This points to a structural difference between start-ups and established cell manufacturers. Start-ups are often more strongly committed to Li-S and therefore tend to drive the technology with greater strategic consistency. Large cell manufacturers have substantial technological and industrial capabilities, but are also deeply embedded in existing lithium-ion technologies, solid-state battery programs, production assets and customer programs. Li-S therefore competes not only technologically, but also strategically with existing investment pathways.

Research activities in Germany and Europe

The analysis of publicly funded Li-S research projects in Germany and Europe shows continuous research activity over the period from 2012 to 2027, with a clear evolution in thematic focus. The combined funding volume from national and European projects, calculated by distributing project budgets linearly over their project durations, rises from a few million euros per year in the 2010s to around 10.5 million euros in 2025. The European contribution becomes visible in the dataset only from 2023 onward. This may indicate a later European project wave, but could also be related to the search methodology and the availability of the project data captured.

The decline in the displayed funding sums after 2025 should only be interpreted to a limited extent as an actual decline in research activity. Since the dataset only includes projects up to around 2025/26 and the budgets were distributed linearly over project durations, a tapering off of the sums in subsequent years is methodologically expected. New projects starting from 2026 onward could increase the funding volume accordingly. Nevertheless, for Germany, a certain dip is visible in the captured data from 2024 onward, which cannot be explained entirely by the visualization logic.

In terms of content, a shift in research priorities can be observed. In the early phase, from around 2012 to 2018, work focused on fundamental material and component challenges. These included the polysulfide shuttle, sulfur cathodes, separators and electrolytes, lithium-metal anodes and modeling. This phase was therefore less characterized by direct industrialization and more by building technological understanding of the central bottlenecks of Li-S batteries.

Between 2019 and 2022, the focus shifted more strongly toward cell concepts, applications and initial scaling questions. Research remained close to materials, but was increasingly linked to cell architectures, pouch cells, manufacturability and applications in aviation or UAV contexts. During this period, funding volumes mostly ranged between around 4.2 and 7.1 million euros per year. In terms of content, this phase marks the transition from addressing individual materials and components toward the question of how these can be transferred into functioning cell concepts.

From 2023 onward, the research landscape becomes visibly more application- and integration-oriented. Topics such as generation-5 battery concepts, solid-state and hybrid approaches, protective layers, sensors, process scaling and pouch cells become more prominent. Overall, however, Li-S research remains strongly shaped by material and component questions. The focus is no longer exclusively on basic or material research, but neither has it fully shifted to industrial cell manufacturing. More recent projects increasingly link cathodes, electrolytes, lithium-metal anodes and interfaces with cell integration, pouch-cell formats, manufacturing processes and validation under more application-oriented conditions.

The actor structure is also changing gradually. Across the entire period, a stable core of Fraunhofer institutes, universities, Helmholtz centers and other non-university research institutions can be observed. These actors form the long-term research base. At the same time, companies, start-ups and application-oriented partners are becoming more prominent over time. Examples such as Theion or IOLITEC in research consortia show that transfer pathways between publicly funded research and industrial development are being established. Nevertheless, the impression remains that research and industrial commercialization still form comparatively separate ecosystems. Publicly funded research has so far produced only a limited number of larger cell samples or clearly industry-oriented prototypes; process technology and prototype production are also less prominent than material, component and cell-concept development.

Moving toward application, but not yet a closed industrialization ecosystem for Li-S batteries

Taken together, patent activity, the company landscape and research projects present a consistent picture: lithium-sulfur batteries remain a relevant high-energy and post-lithium-ion option, but are still in a technologically and industrially open development phase.

For Europe, the picture is ambivalent. On the research side, significant competencies are available, particularly in materials, electrolytes, interfaces, modeling and cell concepts. So far, however, these competencies have translated only to a limited extent into a strong European IP position or a clear roadmap for commercialization. This reflects a pattern familiar from other battery technologies: Germany and Europe conduct intensive research, but translating this into industrial value creation remains challenging. One reason may be that the research agenda is often shaped more strongly by the scientific community than by a closed industrial ecosystem with clear product, customer and production pathways.

Against this background, Lyten’s acquisition of Northvolt activities can be understood as a relevant point of connection. It creates a European footprint for a US company that pursues Li-S much more clearly as its core business than many established cell manufacturers. Whether this will also lead to a transfer of European research results into industrial Li-S activities remains open.

The most likely first market opportunities are probably not in the immediate mass market for passenger cars or stationary storage, but in niches with a particularly high need for gravimetric energy density. These include UAVs, aviation-adjacent applications, space and defense. The growing defense market, the search for battery technologies with reduced raw-material dependencies and questions of technological sovereignty could provide additional momentum for Li-S. In these segments, competitive pressure from established lithium-ion technologies and future solid-state batteries may be lower than in the classic EV or BESS markets. The decisive question will be whether Europe can connect its existing research competencies more strongly with industrial actors, IP strategies and concrete customer markets.

Table 1: Activities and technical KPIs of selected companies active in Li-S batteries

The data used comes from the research project BETSY (funding 03XP0540B) funded by the Federal Ministry of Research, Technology and Space.