QuantumScape launches open platform for sulfide-based solid-state batteries
QuantumScape, a specialist in solid-state batteries and partner of Volkswagen, is introducing an open platform for sulfur-based solid-state batteries. It aims to create new licensing and co-development opportunities for existing customers, as well as enable the integration of components from outside the company.
Illustration: A battery cell developed by QuantumScape with the company’s logo.
Image: QuantumScape
QuantumScape is introducing its new open platform for the next generation of solid-state batteries under the name “Osprey.” It builds upon the company’s previous platform (“QSE”) and incorporates the ceramic separator developed by QuantumScape over the past years, along with the already well-known lithium-metal design without an anode and a solid cathode. With this new platform, the Americans aim primarily to create “new licensing and co-development opportunities for existing customers, as well as to expand offerings for developers of solid-state batteries based on sulfides.”
The background is that the battery industry has been working on solid-state batteries using sulfide electrolytes for some time, but this has not yet resulted in a commercially promising technology. QuantumScape explains: “Approaches to solid-state batteries based on sulfides are very popular in the battery industry. This is due to the high ionic conductivity of sulfide electrolytes and their relatively simple processing. On the other hand, sulfides can react with lithium metal, which reduces the battery’s lifespan.” Furthermore, they generally require high pressure to operate, which is impractical for use in vehicles and many other applications. Although considerable progress has been made throughout the entire value chain, “these efforts were somewhat fragmented, and all faced the same fundamental limitations associated with using sulfides as separators.”
The “Osprey” platform is designed to function precisely at this location and serve as a new open base. QuantumScape states that it is already working with partners from the automotive industry on development projects built on this new platform. The collaboration begins at an early stage of cell development. QuantumScape explains, “While our QSE platform is currently being scaled up as a comprehensive technology solution for mass production, Osprey represents a fundamentally collaborative model for developing solid-state batteries.” Customers who prefer a sulfide-based cathode can either use QuantumScape’s proprietary sulfide-based cathode technology or integrate their own cathode into the Osprey platform. In this way, they can use their own cathode technology, materials, and supply chain while simultaneously benefiting from the advantages of QuantumScape’s ceramic separator.
QuantumScape already refers explicitly to its “Osprey” cells in connection with the new platform, claiming that these cells have achieved 1,000 full charge cycles in initial tests with approximately 80 percent capacity retention, as well as a fast charge capability to 80 percent in five minutes. This was demonstrated under demanding standard conditions, the company states. Specific parameters cited include charge/discharge rates of 1C/1C, a cathode capacity of >5 mAh/cm², a discharge depth of 100 percent at room temperature — all under 1 atmosphere of pressure. Additionally, the platform enables the use of highly charged cathodes, allowing for an energy density at the cell level of up to approximately 1,100 Wh/L.
The compatibility of the cathodes has been demonstrated to work with both the company’s own solid-state cathodes and those from third-party suppliers. Dr. Siva Sivaram, President and CEO of QS, summarized: “Osprey is the result of years of groundbreaking research and development, and we are pleased to introduce it to the public for the first time. The industry has invested heavily in sulfide-based batteries, but it continues to face the same fundamental limitations. As the data shows, Osprey can overcome these constraints. We are convinced that Osprey can unlock the full potential of solid-state batteries, and our goal is to make it the leading platform for their development.”
There are still significant technical challenges to overcome before “Osprey” is ready for mass production. According to the U.S. company, customers in the automotive industry generally prefer prismatic cells in a larger format that offer higher capacity than the current QSE-5 design. However, the results mentioned above come primarily from two-layer test cells. Although these have the same footprint as the QSE-5 cell design, “larger cells will likely require more layers as well as a larger area per layer,” the company states. There is also much development work left to be done in terms of the production process, as it has only been demonstrated on a laboratory scale so far.
Let’s take another look at the company’s history at this point: QuantumScape is one of the promising solid-state battery developers in the U.S., backed primarily by Volkswagen. At the end of 2025, the company announced that it had completed the installation of key facilities for the pilot production of its aforementioned QSE-5 solid-state cells in San Jose, California, with the launch of the pilot line following in February 2026. This so-called Eagle Line is an automated production line for manufacturing QuantumScape’s battery cells, intended to serve as the foundation for future mass production. However, QuantumScape does not aim to carry out its own large-scale manufacturing but rather plans to realize projects on a GWh scale mainly by licensing them to partners.
In October 2025, the Americans reported that they had begun delivering B1 prototypes of the QSE-5 cell. They did not specify to whom the company had passed on these new prototypes at the time. Volkswagen is likely among the recipients, as the relationship between QuantumScape and the Wolfsburg-based company is close and was further strengthened in the summer of 2025. At the heart of their joint program is the Ducati V21L motorcycle, which is equipped with solid-state batteries and is undergoing extensive testing. Additionally, Honda has also become another prominent development partner since mid-year.
It is clear that the cell named QSE-5 is set to become QuantumScape’s first commercial product — with a capacity of 5 Ah, an energy density of over 844 Wh/l, and a charging time of 12.2 minutes to reach 80% SoC (State of Charge). In October 2024, the manufacturer began producing and supplying small batches of B-version prototypes for testing by customers in the automotive industry, according to its own statements.
QuantumScape specifically describes the QSE-5 as a solid-state battery cell measuring 84.5mm x 65.6mm x 4.6mm. The cell is also designed to function at low temperatures down to -30 degrees Celsius. Two cell prototypes preceded the QSE-5 at QuantumScape: the “A0” cell prototypes were delivered to automakers for testing just before Christmas 2022. The so-called “Alpha-2” cells followed in March 2024.