Chonnam National University Researchers Develop New Composite Electrolyte That Improves Safety and Lifespan of Lithium-Metal Batteries

Researchers have developed a new composite solid electrolyte with enhanced ionic conductivity and mechanical durability

GWANGJU, South Korea, Aug. 26, 2026 /PRNewswire/ -- Lithium metal batteries (LMBs), that use pure lithium (Li) for their negative electrodes, are attracting significant attention due to their extremely high theoretical capacity. However, their practical applications are limited by low cycling stability and safety issues, arising from dendrite formation, electrolyte breakdown and uneven solid-electrolyte interface formation.

Solid-state electrolytes are a promising solution to address these challenges. They offer electrochemical stability, mechanical flexibility and manufacturing advantages. Despite these advantages, their practical implementation is hindered by low ionic conductivity, which impedes lithium-ion mobility and exacerbates interfacial issues with lithium-metal anodes.

Now, a research team led by Professor Mincheol Chang from the Department of Polymer Engineering and the School of Polymer Science and Engineering at Chonnam National University, South Korea, has now developed a new tri-layer composite solid electrolyte (CSE) that enhances ion transport and suppresses dendrite formation in LMBs. Prof. Chang explains "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." Their study was published in Volume 38, Issue 43 of Advanced Materials on August 03, 2026.

The proposed tri-layer architecture consists of soft outer layers made of a PEO/lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) matrix surrounding a central hard layer reinforced with polydopamine (PDA)-coated Li₇La₃Zr₂O₁₂ (LLZO) particles as the ceramic additive and poly(ethylene glycol)-block- poly(propylene glycol)-block-poly(ethylene glycol) (PPP) as a ductile polymeric component. This tri-layered membrane was fabricated through solvent-assisted dispersion, tape casting, thermal lamination, and hot pressing.

The soft outer layers are designed offer intimate contact with electrodes and Li⁺ transport channels. Meanwhile, the central PDA@LLZO-PPP layer forms a mechanically robust and highly conductive backbone. Specifically, the chemically active PDA-coated LLZO (PDA@LLZO) particles improve Li⁺ - ion mobility through hydrogen bond-coupling between PDA and PEO chains and percolating conduction pathways. PDA also improves Li⁺-ion concentration by selectively interacting with TFSI^- ions. The flexible PPP polymer reinforces the hybrid network, improving its mechanical elasticity while helping suppress lithium dendrite growth.

In experiments, the optimized CSE-30 design with 30% by weight of PDA@LLZO incorporation and equal layer thicknesses, achieved nearly four times higher ionic conductivity over plain PEO. It also demonstrated a high lithium transference number (a measure of efficient Li-ion transport) of 0.81. In symmetric cell tests, CSE-30 offered over 1000 hours of stable, dendrite free cycling. In full cell tests, it delivered an impressive capacity of 133.6 mAhg^-1 with over 80% capacity retention after 1000 charging/discharging cycles.

Additionally, in a flexible pouch-cell configuration, even when the cell was folded or partially cut, it continued powering an LED, demonstrating both mechanical durability and functional reliability.

"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," remarks Prof. Chang.

Overall, this innovative tri-layer design offers a practical blueprint for developing safer, longer-lasting batteries, paving the way for lithium-metal batteries in electric vehicles, consumer electronics, wearable devices, and grid-scale energy storage.

Reference
Title of original paper: Surface-Functionalized LLZO-Incorporated Multilayer Composite Solid Electrolytes for Dendrite Suppression and Efficient Ionic Conduction in Lithium–Metal Batteries
Journal: Advanced Materials
DOI: 10.1002/adma.73879 

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SOURCE Chonnam National University