Chinese researchers achieve solid-state battery breakthrough, lowering pressure from hundreds of megapascals to 5 MPa
Researchers at the University of Science and Technology of China have reported a breakthrough that addresses a central obstacle to the practical deployment of all-solid-state lithium batteries: their reliance on extremely high external pressure during operation. The findings, published on January 8, 2026, in Nature Communications, describe a new solid electrolyte that enables stable battery cycling at substantially lower pressure than previously reported.
All-solid-state lithium batteries are widely studied for their potential to combine higher energy density with improved safety compared with conventional liquid lithium-ion batteries. However, because both the electrolyte and electrodes are solid, prior research has shown that maintaining adequate solid-solid interfacial contact typically requires external pressures of tens to hundreds of megapascals. Such pressure levels are difficult to achieve in practical battery systems, which has limited the technology largely to laboratory environments.
The research team, led by Professor Ma Cheng, developed a new inorganic solid electrolyte composed of lithium, zirconium, aluminum, chlorine, and oxygen, chemically described as 1.4Li2O-0.75ZrCl4-0.25AlCl3. Compared with mainstream inorganic solid electrolytes, including sulfide-based materials, the new electrolyte exhibits substantially lower mechanical stiffness. Its Young’s modulus is reported to be less than 25 percent of comparable materials, while its hardness is below 10 percent, allowing it to deform more readily under applied pressure.
Despite this mechanical compliance, the electrolyte remains in an inorganic powder form rather than behaving as a gel. This allows compatibility with industrial processes such as roll-to-roll manufacturing and high-pressure calendaring, avoiding excessive material flow during processing. Using a dry-fabrication method suitable for scaled production, the research team assembled small pouch-type all-solid-state battery cells incorporating ultra-high-nickel ternary cathodes and lithium-metal anodes.
Electrochemical testing showed that the electrolyte delivers ionic conductivity above 2 millisiemens per centimeter at room temperature, exceeding the level generally regarded as necessary for practical battery operation. These combined properties enabled all-solid-state batteries to cycle stably under an external pressure of 5 megapascals, representing a significant reduction from previously reported pressure requirements, while maintaining stable performance over several hundred charge-discharge cycles.
The study also addressed material cost. Unlike sulfide solid electrolytes that rely on high-purity lithium sulfide, the new electrolyte uses zirconium tetrachloride as a core raw material. The researchers estimate the material cost at approximately 43.70 USD per liter, which is below 5 percent of the cost of mainstream sulfide solid electrolytes.
According to peer review comments cited by the authors, the reported breakthrough is expected to make an important contribution to all-solid-state battery research and may help bridge laboratory-scale development and large-scale practical application.
