Summary

QuantumScape (NYSE: QS) is a San Jose, California solid-state battery developer focused on a sulfide-based lithium-metal cell with a proprietary ceramic separator. The company is the highest-profile independent pure-play in the space, backed by Volkswagen and publicly listed since 2020. Its QSE-5 cell (5 Ah, 844 Wh/L, 301 Wh/kg) began shipping B1-grade samples to automotive customers in Q3 2025. The Eagle Line pilot production facility was inaugurated in February 2026. A manufacturing partnership with Murata Manufacturing — a Japanese ceramics precision specialist — was announced in April 2025 for scaling the company’s proprietary Cobra ceramic separator process.

Key Facts

  • Founded: 2010
  • HQ: San Jose, CA, USA
  • Type: Public (NYSE: QS)
  • Key backers: Volkswagen (strategic investor since 2018; primary automotive launch partner)
  • Technology: Sulfide-based lithium-metal cell; proprietary ceramic separator (“Cobra” process)
  • QSE-5 cell specs (verified): 5 Ah capacity; 844 Wh/L volumetric density; 301 Wh/kg gravimetric density; 12.2-minute 10–80% charge; >95% capacity retention at 1,000 cycles
  • Current milestone: B1-grade samples shipping to automotive customers (Q3 2025); Eagle Line pilot production inaugurated February 2026
  • Manufacturing partner: Murata Manufacturing (ceramics expertise for Cobra separator scale-up; joint development agreement signed Oct 2025)
  • Mass production target: ~2027–2028 (customer-dependent)

What It Is / How It Works

QuantumScape’s cell is a lithium-metal solid-state design using a sulfide-based solid electrolyte with a ceramic separator as the core differentiator. The separator is the thin membrane between the anode and cathode; QuantumScape’s version is a dense ceramic film that physically blocks lithium dendrite growth (the failure mode that causes lithium-metal cells to short-circuit) while conducting ions efficiently.

The company’s Cobra manufacturing process is a ceramic film deposition technique developed specifically to produce these separators at scale and with consistent quality. Cobra was fully integrated into QuantumScape’s baseline production in 2025 and is central to the Eagle Line pilot’s output. The name of the process refers to the serpentine or coiled nature of the deposition path, though the specific process chemistry is proprietary.

The Murata Manufacturing partnership addresses the most significant remaining scale challenge: Murata is one of the world’s leading precision ceramics manufacturers (best known for ceramic capacitors), and its manufacturing expertise in ceramics material formulation, sheet forming, and firing maps directly to what is needed for high-volume ceramic separator production. The April 2025 framework agreement and October 2025 joint development agreement represent QuantumScape’s strategy to vertically integrate critical supply rather than own all manufacturing in-house.

The QSE-5 is the first commercial-format cell QuantumScape has shipped externally. The B1 designation is an automotive development milestone — it represents a cell format that OEM customers can test in vehicle-level integration, ahead of the A-sample and production-intent C-sample stages. QuantumScape’s launch customer is understood to be Volkswagen, though other undisclosed automotive customers have also received samples.

Notable Developments

  • 2026-02: Eagle Line pilot production facility inaugurated in San Jose; designed for higher-volume QSE-5 cell production.
  • 2025-10: Joint development agreement with Murata Manufacturing signed for manufacturing of ceramic separators at scale. (Murata)
  • 2025 (Q3): B1-grade QSE-5 samples begin shipping to automotive launch customers. (QuantumScape IR)
  • 2025-04: Framework agreement with Murata Manufacturing announced; confirms ceramics collaboration. (QuantumScape)
  • 2025: Cobra separator process fully integrated into baseline production; enables gigawatt-level scaling.
  • 2020: SPAC IPO on NYSE (QS).
  • 2018: Volkswagen Group strategic investment; partnership formalized.

Key People

  • Siva Sivaram — CEO (since 2022); previously President of Technology at Western Digital
  • Jagdeep Singh — Co-founder; now Executive Chairman; was CEO through early commercialization phase
  • Tim Holme — CTO and co-founder

Claim Verification

Claim: QSE-5 specs — 844 Wh/L, 301 Wh/kg, 12.2-min charge, 95%+ capacity at 1,000 cycles

Status: Verified (QuantumScape internal; shipped to external automotive customers for independent validation)

Supporting sources:

Refuting / questioning sources:

  • No specific refutation of the QSE-5 specs; independent OEM validation reports have not yet been published (B1 testing is ongoing as of early 2026)

Summary: Cell specs are company-reported from internal characterization and are in the process of being validated by automotive OEM customers. No independent peer-reviewed publication yet, but the B1 sample shipping milestone indicates readiness for external scrutiny.

Sources