CATL Accelerates Sulfide Solid-State Battery Development Toward 2027 Pilot

Chinese battery giant CATL is pushing forward with its solid-state battery technology as it targets a pilot production launch in 2027. A newly published patent (PCT/CN2025/086345) reveals the company’s focus on a specialized cathode material and manufacturing process designed to enhance the stability of sulfide electrolytes. These electrolytes have long faced challenges with interfacial contact failures—an issue CATL aims to resolve as it transitions from lab-scale prototypes to automotive-grade cells.

Internally dubbed Ningde Shidai All-Solid-State, CATL’s all-solid-state battery is reported to have achieved an energy density of 500 Wh/kg. The technology currently sits at readiness level 4, meaning it is being validated in a laboratory setting. By 2027, the company expects to reach level 7 or 8—where system prototypes are demonstrated in real-world environments or systems are fully qualified for pilot integration into vehicles.

On the supply chain front, CATL has locked in a major agreement with Guangdong Jiayuan Technology. Signed in November 2025, the framework deal reserves 626,000 tons of copper foil capacity for the years 2026 through 2028, with an estimated value of 66 billion yuan. This ensures access to critical anode current collector materials needed for both semi-solid and all-solid-state battery development.

Still, scaling remains a formidable challenge. Moving from 20 Ah lab samples to 60 Ah automotive-grade cells requires overcoming significant engineering hurdles. Sulfide-based solid-state stacks demand sustained high compression to maintain stable interfacial contact, often necessitating rigid casing designs that can eat into the weight savings from high energy density.

Cost is another major barrier. Currently, sulfide solid-state cells are three to five times more expensive than conventional lithium-ion batteries. As a result, CATL expects early adoption in niche applications like drones and robotics, where energy density takes priority over cost sensitivity.

Industry forecasts estimate all-solid-state battery shipments could hit 13.5 GWh by 2028, compared to 160 GWh for semi-solid variants. With its latest patent filings and strategic supply partnerships, CATL is positioning itself to lead in the emerging solid-state battery space.