GIST Solves Key Lithium Metal Battery Challenge with a 2-Minute Process

Formation of the Anode Surface Governing Lithium Transport and Stability

(From left) Professor Eom Kwangseop, PhD candidate Lee Changhyun. Provided by Gwangju Institute of Science and Technology

The Gwangju Institute of Science and Technology (GIST) announced on the 9th that the research team led by Eom Gwangseop, director of the Next Generation Energy Research Institute and professor in the Department of Materials Science and Engineering, has developed a technology that forms, in just 2 minutes, the surface (interface) that governs lithium transport and stability at the anode of lithium metal batteries by repeatedly applying short electrical signals to finely tune the electrode surface, a method known as an electrochemical pulse deposition process.

The core of this research is the formation of a nanowire precursor (SCN) structure, which is much thinner than a human hair, by introducing only a minute amount of tin onto the copper surface that carries current at the battery anode. The team demonstrated that this enables the rapid and simple fabrication of a stable interface on which lithium metal can be deposited evenly without clustering on one side.

For electric vehicles (EVs) and energy storage systems (ESSs), it is crucial that stored electricity can be used safely and reliably when needed. Commercial lithium-ion batteries are currently the main technology used in these systems.

Lithium-ion batteries have the advantage of storing a large amount of energy relative to their size and weight, but the structural limitations of graphite anodes cap the amount of energy that can be stored. As a result, interest is growing in next-generation high-energy battery technologies that can surpass conventional lithium-ion batteries.

The research team focused on "lithium metal batteries," which use lithium metal instead of graphite as the anode. Lithium metal batteries can theoretically store a very large amount of energy and therefore have great potential as next-generation high-energy batteries.

However, if lithium ions do not move uniformly along the interface during charge and discharge, lithium can accumulate unevenly on the anode surface and grow into sharp crystal structures known as dendrites.

Schematic comparing the native solid electrolyte interphase (SEI) formed on an untreated copper (Cu) surface with low grain boundary density and the SCN-derived solid electrolyte interphase (SEI) with multiple grain boundaries.

As dendrites grow, the electrode interface becomes unstable, causing battery performance and lifespan to deteriorate rapidly. Therefore, for lithium metal batteries to be put into practical use, new electrode and interface design technologies are needed to control lithium-ion transport so that it is fast and uniform.

The research team applied a precise design strategy that preserves only the desired functions while minimizing side effects. By introducing tin in an atomically minute amount, they succeeded in creating an anode interface to which lithium adheres well, without causing issues such as excessive mixing or deformation of the material.

As a result, they were able to guide lithium metal to deposit evenly instead of clustering on one side, and confirmed that deformation of the electrode structure and performance degradation could be effectively suppressed. In particular, the nanostructured interface, which is much thinner than a human hair, naturally transforms in the early stages of charging into a protective solid electrolyte interphase (SEI), forming pathways through which lithium ions can move rapidly and stably.

Through this precisely engineered anode interface structure, the research team increased the lithium-ion transport rate to about 24 times that of conventional copper interfaces. Consequently, they were able to effectively suppress both the long-standing problem in lithium metal batteries of non-uniform lithium deposition and the growth of dendrites.

Comparison of the electrochemical properties of the solid electrolyte interphase (SEI) formed on untreated copper (Bare Cu) current collectors and nanowire precursor (SCN) current collectors.

The batteries incorporating this nanowire interface structure operated stably for more than 900 hours, and in practical cell tests using a lithium iron phosphate (LFP) cathode, they retained 98.2% of their initial capacity even after 480 cycles under high-rate conditions in which charging and discharging were completed within about 1 hour.

This means that both fast charging and long battery life were achieved at the same time, indicating strong potential for deployment in industrial applications such as electric vehicles and energy storage systems.

Professor Eom Gwangseop said, "This study is significant in that it demonstrates that the most critical challenge for the commercialization of lithium metal batteries, namely dendrite formation, can be effectively addressed solely through electrochemical interface design of the lithium anode," adding, "Because this simple process can be implemented within 2 minutes while achieving both fast charging and long lifespan, it is a practical technology that can be directly applied to existing battery manufacturing lines."

This research, supervised by corresponding author Professor Eom Gwangseop of the GIST Department of Materials Science and Engineering and conducted by PhD candidate Lee Changhyun as first author, was supported by the Mid-career Researcher Program of the Ministry of Science and ICT and the National Research Foundation of Korea, as well as the Advanced Future Radiation Technology Development Program.

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