A research team in South Korea has developed a breakthrough transfer printing technology that forms protective thin layers on lithium metal surfaces—an innovation poised to solve the long-standing dendrite issue plaguing next-generation lithium-metal batteries.
Dr. Jungdon Suk's team (Advanced Battery Research Center) at the Korea Research Institute of Chemical Technology (KRICT) has successfully transferred hybrid protective layers composed of solid polymers and ceramics onto lithium metal using a solvent-free process. Unlike conventional wet coating methods, this technique enables uniform coating over large areas without damaging the reactive lithium surface, marking a significant step toward commercial viability.
Lithium-metal batteries are a next-generation energy storage system that replace graphite with lithium metal as the anode. Offering ten times the theoretical capacity of conventional lithium-ion batteries, lithium-metal anodes are a key material in solid-state and lithium-sulfur batteries, which demand high energy density. However, the risk of dendrite formation during charge/discharge cycles raises safety concerns, including short-circuiting and fire hazards, while also limiting battery lifespan. Moreover, traditional wet-coating processes, which rely on organic solvents, introduce impurities and surface damage that complicate large-scale production and commercialization.
To overcome these challenges, the research team developed two types of protective layers: a dual-layer composed of alumina (Al₂O₃) and gold (Au), and a hybrid layer combining ceramic (Al-LLZO) and polymer components. These protective layers were subsequently laminated onto lithium metal using a roll-based trasnfer printing technique, marking the first demonstration of this method in this field. This technique forms the protective layer on a separate substrate and then transfers it to lithium using pressure, eliminating the need for solvents and minimizing lithium damage while improving uniformity and process reproducibility.
In earlier studies, the Al₂O₃–Au dual layer effectively suppressed dendrite growth and maintained stable cycling by leveraging mechanical strength and reduced interfacial resistance. This work was the first to introduce transfer printing as a solution to interface instability and the limitations of wet coating.
Building on this, the research team has now demonstrated a method for transferring ionically conductive, flexible hybrid protective layers over a 245 × 50 mm area with a thickness of just 5 μm. These hybrid layers suppress dendrite growth and induce uniform lithium-ion flux at the interface between the electrode and electrolyte, enabling stable cycling performance. The uniform transfer of large-area protective films confirms both technological advancement and scalability for commercialization.
In pouch-cell tests, the hybrid-protected lithium anode maintained 81.5% capacity retention after 100 charge/discharge cycles, with a low overpotential of 55.34 mV and a high Coulombic efficiency of 99.1%—more than twice the stability of bare lithium cells. Even under high-rate conditions that fully discharge the battery within 9 minutes, the cells retained 74.1% of their initial capacity, demonstrating fast, stable, and efficient cycling characteristics.
The team expects this innovation to accelerate the practical use of lithium-metal batteries in high-energy applications such as electric vehicles and energy storage systems (ESS). Moreover, the technology may extend to solid-state and lithium-sulfur batteries, further contributing to the advancement of next-generation battery platforms.
"This study combines novel protective materials and a scalable transfer printing process to overcome the critical challenges of interfacial instability and wet-processing limitations in lithium-metal batteries," said Dr. Suk. KRICT President Dr. Young-Kuk Lee added, "This represents one of the most practical solutions for enabling high-energy-density lithium-metal batteries and could boost Korea's competitiveness in the global battery industry."
This research was published in the international journal Energy Storage Materials (IF: 20.2), with two separate articles on the Al₂O₃–Au dual-layer and the ceramic–polymer hybrid film appearing in February and July 2025, respectively.
