New Low-Pressure Solid-State Battery Design Marks Major Research Milestone

Researchers at the University of Science and Technology of China have announced a major advance that could accelerate the real-world adoption of all-solid-state lithium batteries.

The team has developed a new solid electrolyte that allows these batteries to operate reliably under much lower external pressure than previously required, overcoming one of the technology’s biggest practical hurdles. The findings were published on January 8, 2026, in Nature Communications.

All-solid-state lithium batteries are considered a next-generation alternative to conventional lithium-ion cells, promising higher energy density and improved safety by eliminating flammable liquid electrolytes. However, their widespread use has been constrained by a fundamental challenge.

Because both the electrodes and the electrolyte are solid, maintaining stable contact at their interfaces typically requires extremely high external pressures, often ranging from tens to hundreds of MPa. Such conditions are impractical for commercial battery packs, keeping most demonstrations confined to laboratory settings.

Led by Professor Ma Cheng, the research team addressed this issue by designing a new inorganic solid electrolyte made from lithium, zirconium, aluminum, chlorine and oxygen, with the chemical composition 1.4Li₂O–0.75ZrCl₄–0.25AlCl₃.

Compared with commonly used inorganic electrolytes, including sulfide-based materials, the new compound is significantly more mechanically compliant. Its Young’s modulus is reported to be less than a quarter of that of conventional alternatives, while its hardness is under 10 percent, allowing it to deform more easily and maintain interfacial contact at lower pressures.

Crucially, the electrolyte remains a dry inorganic powder rather than a gel-like material. This ensures compatibility with industrial manufacturing techniques such as roll-to-roll processing and high-pressure calendaring, without the risk of excessive material flow.

Using a dry fabrication process suitable for scale-up, the team built small pouch-type all-solid-state cells featuring ultra-high-nickel ternary cathodes and lithium-metal anodes.

Testing showed the electrolyte achieves room-temperature ionic conductivity above 2 mS/cm, exceeding the threshold typically considered necessary for practical battery operation. As a result, the batteries were able to cycle stably under an external pressure of just 5 MPa, while maintaining consistent performance over several hundred charge-discharge cycles.

Cost was also a focus. By using zirconium tetrachloride instead of expensive lithium sulfide, the researchers estimate the material cost at roughly $43.70 per litre, less than 5% of that of mainstream sulfide electrolytes. 

Peer reviewers noted that this breakthrough could play a key role in bridging the gap between laboratory research and large-scale deployment of all-solid-state batteries.

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