Solid-state batteries advance to engineering validation phase

The all-solid-state battery industry reached a pivotal milestone in 2026, with leading Japanese, Korean, and Chinese manufacturers moving beyond laboratory research into engineering validation — a phase that brings the technology closer to automotive deployment even as costs for key materials drop sharply.

Industry Advances to TRL 5–6

TrendForce's "Quarterly Report on Developments in Global SSB Industry, 2Q26," published on August 12, found that Technology Readiness Levels for all-solid-state batteries have advanced to TRL 5–6 at leading companies, up from the proof-of-concept stage of TRL 1–3. Toyota, Honda ↗ 0.48%, Nissan, and Samsung SDI are at the front of small-scale pilot production, with Japanese suppliers having already verified key automotive-grade performance metrics.trendforce

Nissan's thick-format 23-layer stacked automotive ASSB cell has completed charge-discharge testing and demonstrated better capacity retention than conventional liquid lithium-ion batteries, according to TrendForce. Chinese companies including CATL Contemporary Amperex Technology Co., Limited, BYD, and FAW are advancing toward TRL 4–5.trendforce

Applications are also expanding beyond electric vehicles into drones, eVTOLs, microelectronics, construction machinery, and embodied robots, with orders beginning to materialize from companies including Maxell, Ilika, ProLogium, and Factorial.trendforce

Lithium Sulfide Costs Collapse

A key enabler of ASSB progress is the rapid decline in material costs. Lithium sulfide (Li₂S) prices have fallen by more than 50% over the past six months, reaching approximately $219 per kilogram in June 2026, TrendForce reported. Global installed lithium sulfide capacity exceeded 600 metric tons in the first half of 2026 and is expected to reach the thousand-ton scale by 2027. Monthly shipments from some suppliers have grown from kilogram-scale to metric-ton-scale volumes since early 2026.trendforce

QuantumScape and Solivis Push Commercialization

QuantumScape ↗ 0.16% presented at the J.P. Morgan 2026 Automotive Conference on August 12, where CFO Kevin Hettrich outlined a capital-light licensing model and reported $40 million in cumulative customer billings. The company said its Eagle pilot line, launched in February 2024, is operating above 90% uptime and serving as a sampling platform for Volkswagen, Honda, and two unnamed top-10 automakers. Hettrich said QuantumScape's QSE-5 cell offers 800 Wh/L energy density and a 10-to-80% charge time of about 12 minutes.investing

Separately, South Korea's Solivis closed a 23 billion KRW (roughly $16 million) Series C round backed by Openwater Investment and Seulgi Asset Management to scale solid-state battery materials production.dealroom+1