Nature Communications published research on September 10, 2026, detailing a quasi-dry process that uses the organic additive alpha-pinene to fabricate freestanding sulfide electrolyte films. The method targets all-solid-state batteries, which require electrolyte films combining thinness, high ionic conductivity, and large-area feasibility to improve energy density and enable industrial-scale production.
Researchers at Shanghai Jiao Tong University and Contemporary Amperex Technology Co. Limited authored the study under DOI 10.1038/s41467-026-77590-1. Alpha-pinene is chemically compatible with Li5.5PS4.5Cl1.5, improves film flexibility via stress dissipation, enhances ionic conductivity by promoting a more even distribution of the polytetrafluoroethylene binder, and facilitates film densification through lubrication.
Performance and Cell Testing
The resulting films show reduced porosity, dropping from 12.24% to 7.78%, while retaining over 85% of the ionic conductivity found in the pristine powder. They exhibit an ionic conductivity of 4.79 mS/cm at 25 degrees Celsius, reach a thickness of 28 micrometers, and measure 30 by 10 centimeters in lateral dimensions.
Full cells built with Li4Ti5O12, Li5.5PS4.5Cl1.5, and [email protected] achieved a capacity retention of 93% after 500 cycles at 1 C under 2 MPa. At the stack level, a 50 mAh pouch cell retained 83% capacity after 1000 cycles at 0.5 C under 2 MPa.
Funding and Acknowledgments
Contemporary Amperex Technology Co. Limited provided funds to support the work. Z.N. received financial support from the National Natural Science Foundation of China under Grant No. 22309095, while L.L. received support from the Science and Technology Commission of Shanghai Municipality under Grant No. 24DZ3001402 for positive electrode material development. The authors thanked Jiaji Li and Yuanyang Shui for assistance with rheological measurements.
