Researchers at the University of Science and Technology of China said they have developed a new solid electrolyte that significantly reduces the external pressure required for operating all-solid-state lithium batteries, addressing one of the main barriers to their commercial deployment.
The findings, published on Jan. 8, 2026, in the journal Nature Communications, describe an inorganic solid electrolyte that allows stable battery operation at pressures far below those typically reported in earlier studies. All-solid-state lithium batteries are viewed as a potential successor to conventional lithium-ion cells because of their higher energy density and improved safety, but their practical use has been constrained by demanding mechanical requirements.
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Previous research has shown that maintaining reliable contact between solid electrolytes and solid electrodes often requires external pressures ranging from tens to hundreds of megapascals, levels that are difficult to achieve and sustain in real-world battery packs. As a result, most all-solid-state battery demonstrations have remained confined to laboratory settings.
The research team, led by Professor Ma Cheng, developed an electrolyte composed of lithium, zirconium, aluminum, chlorine and oxygen, with a chemical formulation described as 1.4Li₂O–0.75ZrCl₄–0.25AlCl₃. According to the study, the material has substantially lower mechanical stiffness than commonly used inorganic solid electrolytes, including sulfide-based systems. Its reported Young’s modulus is less than 25% of comparable materials, while its hardness is below 10%, allowing it to deform more easily and maintain interfacial contact under lower pressure.
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Despite its mechanical compliance, the electrolyte remains a solid inorganic powder rather than a gel, which the researchers said makes it compatible with established industrial processes such as roll-to-roll manufacturing and high-pressure calendaring. Using a dry fabrication process intended to be scalable, the team assembled small pouch-type all-solid-state battery cells incorporating lithium-metal anodes and high-nickel ternary cathodes.
Electrochemical tests showed that the electrolyte achieved ionic conductivity of more than 2 millisiemens per centimetre at room temperature, a level generally considered sufficient for practical battery operation. The batteries were able to cycle stably under an external pressure of 5 megapascals, a substantial reduction compared with previously reported requirements, while maintaining performance over several hundred charge–discharge cycles.
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The study also highlighted potential cost advantages. Unlike sulfide-based solid electrolytes that depend on high-purity lithium sulfide, the new material uses zirconium tetrachloride as a key raw input. The researchers estimated the electrolyte’s material cost at about $43.70 per litre, less than 5% of the cost of mainstream sulfide solid electrolytes.
Peer review comments cited by the authors said the work could make an important contribution to all-solid-state battery research and help narrow the gap between laboratory demonstrations and large-scale practical applications, as automakers and battery manufacturers continue to search for safer, higher-performance energy storage technologies.
