Contemporary Amperex Technology Co. Ltd. (CATL) has secured a new patent for solid-state battery technology and arranged a large-scale supply of copper foil, signaling continued progress toward its goal of pilot production later this decade, according to recent disclosures and media reports.
The patent, published on March 5, 2026, by the World Intellectual Property Organisation (WIPO), outlines CATL’s approach to a sulfide-based solid-state battery. Titled “Positive Electrode Sheet, Solid-State Battery Cell, Battery Device, Electric Device, Positive Electrode Active Material and Preparation Method Therefor,” the document details a layered anode design combining a substrate material, a cobalt-rich material, and a coating incorporating an electrolyte salt.
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According to Electrek, the coating utilizes a fluorine-containing lithium salt, which is designed to react with the sulfide electrolyte to form lithium fluoride. This process aims to create a protective layer for the anode and address the known instability of sulfide electrolytes, a key technical challenge in solid-state battery development.
Industry portal CarNewsChina reported that CATL has already begun pilot production of solid-state batteries with an energy density of 500 Wh/kg. The report added that “technical data indicates the company is currently at technology maturity level 4 and aims to reach levels 7 or 8 by 2027. This level signifies the transition from laboratory prototypes to automotive-grade cells ready for pilot-scale vehicle integration,” according to CarNewsChina.
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CATL has previously stated its ambition to produce a limited series of solid-state batteries by 2027. In the near term, the company is working to scale from 20-Ah samples to 60-Ah automotive-grade prototypes, as it prepares for eventual vehicle integration.
To support future production, CATL has also secured a substantial supply of copper foil, a critical battery component. CarNewsChina reported that the company reserved 626,000 tonnes of copper foil from Guangdong Jiayuan Technology for the 2026–2028 period, in a deal valued at approximately €8.4 billion. The portal described the agreement as a strategic move to stockpile materials for both semi-solid and solid-state batteries.
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Despite the progress, challenges remain. In October 2025, CATL acknowledged that while “scientific challenges have been largely resolved,” technical and cost barriers persist. “Sulfide solid-state cells are currently 3–5 times more expensive than conventional lithium-ion,” according to CarNewsChina, highlighting the economic hurdles facing large-scale commercialization.
CATL has been developing solid-state battery technology for more than a decade. Earlier statements from Chief Developer Wu Kai indicated that a significant research and development team is focused on advancing next-generation battery systems, supported by collaborations with universities and industry partners.
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The company is also part of a broader national effort to accelerate solid-state battery adoption. In early 2024, CATL joined other major battery and automotive manufacturers in the China All-Solid-State Battery Collaborative Innovation Platform (CASIP), a consortium initiated by the Chinese government. The group aims to advance key technologies, establish supply chains, and enable mass production of competitive solid-state batteries by 2030.
Participants in the alliance include battery makers such as CALB, EVE Energy, SVOLT, Gotion High-Tech, and FinDreams Battery, as well as automakers including BYD and Nio. The initiative also involves state-backed funds and academic institutions, underscoring China’s coordinated approach to maintaining its leadership in the global electric vehicle battery market amid the shift toward solid-state technology.
