Researchers at Chonnam National University in South Korea have developed a new tri-layer composite solid electrolyte designed to improve the safety, cycling stability, and lifespan of lithium-metal batteries, which are being studied for future electric vehicles.
Lithium-metal batteries use pure lithium for the negative electrode and offer high theoretical capacity, but dendrite formation, electrolyte degradation, and unstable interfaces continue to limit their practical use.
The tri-layer composite electrolyte is designed to improve lithium-ion conductivity, cycling stability, and mechanical durability in lithium-metal batteries.
The research team, led by Professor Mincheol Chang of Chonnam National University’s Department of Polymer Engineering and School of Polymer Science and Engineering, developed a composite solid electrolyte that combines soft outer layers with a mechanically reinforced central layer.
The design is intended to improve lithium-ion transport while suppressing dendrite formation.
The outer layers use a polyethylene oxide, or PEO, and lithium bis(trifluoromethanesulfonyl)imide, or LiTFSI, matrix to improve electrode contact and provide lithium-ion transport channels. The central layer incorporates polydopamine-coated Li7La3Zr2O12, or LLZO, ceramic particles and a flexible triblock copolymer.
According to the researchers, the polydopamine coating improves lithium-ion mobility and helps create conductive pathways through the electrolyte, while the polymer component improves elasticity and reinforces the structure.
“Inspired by the natural adhesive proteins mussels use to stick to rocks, our tri-layer composite incorporates chemically active ceramic fillers with a flexible triblock copolymer, boosting ionic conductivity and mechanical strength,” Chang said.
In testing, the optimized CSE-30 electrolyte, containing 30% by weight of PDA-coated LLZO, achieved nearly four times the ionic conductivity of plain PEO and a lithium transference number of 0.81.
The electrolyte also supported more than 1,000 hours of stable, dendrite-free cycling in symmetric-cell testing. In full-cell tests, it delivered a capacity of 133.6 mAh/g and retained more than 80% of its capacity after 1,000 charge-discharge cycles.
The researchers also tested the electrolyte in a flexible pouch-cell configuration. The cell continued powering an LED after being folded or partially cut, demonstrating the mechanical durability of the electrolyte design.
“Our electrolyte is designed for next-generation lithium-metal batteries that can enable longer driving ranges for electric vehicles, safer batteries, flexible and wearable electronics, and long-cycle-life grid-scale energy storage,” Chang said.
Reference
“Surface-Functionalized LLZO-Incorporated Multilayer Composite Solid Electrolytes for Dendrite Suppression and Efficient Ionic Conduction in Lithium–Metal Batteries;” Journal: Advanced Materials (August 2026); DOI: 10.1002/adma.73879
Filed Under: Batteries, Technology News