A research team in South Korea has created an innovative transfer printing process that applies protective thin layers to lithium metal surfaces, addressing the persistent dendrite problem affecting next-generation lithium-metal batteries.

Dr. Jungdon Suk’s team at the Korea Research Institute of Chemical Technology (KRICT) has successfully applied hybrid protective layers made of solid polymers and ceramics onto lithium metal through a solvent-free method. This process allows for uniform coating over extensive regions without compromising the reactive lithium surface, representing a notable advancement towards commercial feasibility, in contrast to traditional wet coating methods.

Lithium-metal batteries represent an advanced energy storage device that substitutes graphite with lithium metal for the anode. Lithium-metal anodes provide tenfold the theoretical capacity of traditional lithium-ion batteries and are essential components in solid-state and lithium-sulfur batteries that require elevated energy density. The potential for dendrite growth during charge and discharge cycles poses safety risks, such as short-circuiting and fire dangers, while also diminishing battery longevity. Furthermore, conventional wet-coating methods that utilise organic solvents introduce contaminants and surface degradation, complicating large-scale manufacturing and commercialisation.

To address these issues, the study team created two varieties of protective layers: a dual-layer consisting of alumina (Al₂O₃) and gold (Au), and a hybrid layer integrating ceramic (Al-LLZO) and polymer elements. These protective layers were later laminated onto lithium metal with a roll-based transfer printing approach, representing the inaugural demonstration of this method in this domain. This technology creates a protective layer on a distinct substrate and subsequently transfers it to lithium by pressure, thereby obviating the necessity for solvents and reducing lithium damage while enhancing uniformity and process reproducibility.

Previous research demonstrated that the Al₂O₃–Au dual layer successfully inhibited dendrite formation and ensured steady cycling by utilising mechanical strength and minimising interfacial resistance. This study was the first to present transfer printing as a remedy for interface instability and the constraints of wet coating.

The research team has now developed a way for transferring ionically conductive, flexible hybrid protective coatings over an area of 245 × 50 mm with a thickness of only 5 μm. These hybrid layers inhibit dendrite formation and promote uniform lithium-ion flow at the interface between the electrode and electrolyte, facilitating steady cycling performance. The consistent application of extensive protective layers validates both technological progress and scalability for commercial use.

In pouch-cell evaluations, the hybrid-protected lithium anode exhibited 81.5% capacity retention after 100 charge/discharge cycles, characterised by a low overpotential of 55.34 mV and a high Coulombic efficiency of 99.1%, demonstrating over twice the stability of unprotected lithium cells. Even under high-rate settings that completely deplete the battery in 9 minutes, the cells maintained 74.1% of their original capacity, exhibiting rapid, stable, and efficient cycling properties.

The team anticipates that this invention may expedite the actual implementation of lithium-metal batteries in high-energy applications, including electric vehicles and energy storage systems (ESS). Furthermore, the technology may encompass solid-state and lithium-sulfur batteries, hence enhancing the development of next-generation battery systems.

“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 study was published in the international journal Energy Storage Materials (IF: 20.2), with two distinct publications on the Al₂O₃–Au dual-layer and the ceramic–polymer hybrid film, released in February and July 2025, respectively.

KRICT is a government-funded research institute in South Korea, advancing chemical technologies since 1976. It focuses on global challenges in chemistry and engineering. More at https://www.krict.re.kr/eng.

Funding: NST Global TOP Strategy Project (GTL24011-000) and KRICT internal R&D.

Original Publication
Authors: Junyoung Choi, Jinkyu Park and Jungdon Suk.
Journal: Energy Storage Materials
DOI: 10.1016/j.ensm.2025.104428
Article Title: A Scalable Transfer-printed Hybrid Interface for Dendrite-free and High-energy Lithium-metal Batteries
Article Publication Date: 3-Jul-2025