QuantumScape’s Osprey solid-state cell hits 1,000 cycles

By Rebecca Stone

QuantumScape said on Wednesday that a two-layer Osprey all-solid-state cell completed 1,000 full 1C charge-and-discharge cycles from 0% to 100%, retaining about 80% of capacity at 30°C and one atmosphere. The company calls it the first public data of its kind for a sulfide-based cathode.

One atmosphere changes the proposition. Sulfide cells from rivals typically need 30 to 100 atmospheres or more of clamping in laboratories, adding steel end plates, weight and cost to a pack. CEO Siva Sivaram said: “The industry has invested heavily in sulfide-based batteries but keeps hitting the same fundamental limits.”

What did QuantumScape actually test?

QuantumScape’s current QSE-5, which it ships as samples from its Eagle Line pilot production operation in San Jose, pairs a solid ceramic separator with a conventional high-nickel cathode soaked in liquid catholyte.

Osprey makes the cell fully solid-state by replacing the cathode’s liquid electrolyte with a solid sulfide cathode. It retains the ceramic separator and the anode-free lithium-metal design, in which lithium plates against the separator on first charge.

• Cycle test: The two-layer cell used a 50 x 65 mm cathode, the same area as one QSE-5 layer, and a commercial-grade cathode loading of 5.5 mAh/cm². Electrek estimated the cell’s capacity at roughly 0.3 to 0.4 Ah, against about 5 Ah for a QSE-5.
• Fast charge: The press release’s five-minute charging result ran from 10% to 80%; the white paper says a two-layer cell reached that point at 10C and 80°C.
• Cold operation: A single-layer cell with a 21 x 21 mm cathode, discharged at C/3 below -20°C, retained 68% of its room-temperature capacity.
• Energy density: Up to about 1,100 Wh/L is a projection based on high-loading cathodes tested in an 11 mm coin cell at three atmospheres for 100 cycles, not a demonstrated Osprey-cell rating. QSE-5’s rated density is 844 Wh/L.

These results came from different cells under different constraints. The 1,000-cycle result operated at 30°C and one atmosphere; the five-minute charge required 80°C; and the roughly 1,100 Wh/L figure remains a projection from coin-cell work at three atmospheres.

Can Osprey attract sulfide developers?

QuantumScape describes Osprey as an open platform compatible with a range of cathode chemistries. The company says it has tested all-solid cathodes developed in-house and by automotive customers, and already works with automotive partners on Osprey. That opens licensing and co-development options for existing customers and developers of sulfide-based cells.

The laboratory remains the boundary. QuantumScape’s white paper says Osprey has been demonstrated “at laboratory scale” and that “significant work remains in process engineering.” The company gave no commercial timeline.

Separately, QuantumScape already licenses its technology to Volkswagen’s PowerCo and Honda. It reported $9.8 million in customer billings in the third quarter, providing a measure of current licensing activity that does not yet include a disclosed Osprey production ramp.

A day earlier, Factorial booked its first revenue on 450 Wh/kg aerospace cells, another commercial milestone arriving as established battery makers work toward sulfide-cell production.

What happens after the lab?

Osprey has no announced production schedule, but QuantumScape has a separate scale-up plan for its existing product: a 100 MWh QSE-5 line targeting production in 2028.

Electrek reported that sulfide competitors are moving on their own timelines. Samsung SDI targets mass production in the second half of 2027, while Toyota aims for 2027 to 2028.

Until QuantumScape supplies a commercial timeline and scaled-cell data, those 2027-28 schedules set the competitive reference point, and Osprey’s advantage will hinge on whether its low-pressure architecture survives process engineering without sacrificing energy density or adding cost.