Research

[POSTECH develops a magnetic-field battery technology that prevents explosions and delivers four times the capacity]

A new battery technology has been developed that delivers significantly higher energy storage—enough to alleviate EV range concerns—while lowering the risk of thermal runaway and explosion. A research team at POSTECH has developed a next-generation hybrid anode that uses an external magnetic field to regulate lithium-ion transport, effectively suppressing dendrite^*1  growth in high-energy-density electrodes.

A POSTECH research team—led by Professor Won Bae Kim of the Department of Chemical Engineering and the Graduate School of Battery Engineering, together with Dr. Song Kyu Kang and integrated Ph.D. student Minho Kim—has introduced a “magneto-conversion^*2” strategy that applies an external magnetic field to ferromagnetic manganese ferrite conversion-type^*3 anodes. The study has been published in the leading energy journal Energy & Environmental Science.

As the electric vehicle and large-scale energy storage markets expand rapidly, the battery industry faces a pressing challenge: developing batteries that store more energy while remaining safe. Lithium metal anodes offer exceptionally high theoretical capacity, but they are prone to forming sharp, needle-like dendrites during repeated charging, which can pierce the separator, cause internal short circuits, and trigger fires or explosions. Meanwhile, conventional graphite anodes—now widely used—have inherent capacity limitations, making next-generation anode technologies essential.

The idea was simple: “If a magnet can align iron filings, why not use it to organize the flow of lithium ions?” When lithium is inserted into the manganese ferrite anode, it produces ferromagnetic metallic nanoparticles. Under an applied magnetic field, these nanoparticles align like tiny magnets inside the electrode. This alignment spreads the lithium ions more evenly across the surface, preventing them from concentrating in specific regions. During this process, the Lorentz force^*4—the force exerted on charged particles in a magnetic field—further disperses the lithium ions, promoting uniform transport. As a result, instead of forming hazardous dendrites, the anode develops a smooth, dense, and uniform lithium metal deposition layer.

In addition, the anode operates as a hybrid system, storing lithium both within the oxide matrix and as metallic lithium deposited on the surface. This dual mechanism enables an energy storage capacity approximately four times higher than that of commercial graphite anodes, while maintaining stable charge–discharge cycling without dendrite formation. Notably, the battery sustained a Coulombic efficiency above 99% for more than 300 cycles, demonstrating excellent long-term stability.

Professor Won Bae Kim, who led the research, stated, “This approach simultaneously addresses the two biggest challenges of lithium metal anodes—instability and dendrite formation. It represents a new pathway toward safer and more reliable lithium-metal batteries.” He added, “We expect this technology to serve as a foundation for improving capacity, cycle life, and charging speed in next-generation batteries.” 

This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Science and ICT (MSIT), , and the Korea Institute for Advancement of Technology (KIAT) grant funded by the Ministry of Trade, Industry and Energy (MOTIE).

DOI: https://doi.org/10.1039/D5EE02644J

1) Dendrite: A needle-like, tree-shaped crystalline structure of lithium metal that forms during repeated charging and discharging. If dendrites grow through the electrode surface and penetrate the separator, they can cause internal short circuits and potentially lead to fires or explosions. Suppressing dendrite formation is therefore a central challenge in the development of lithium-metal batteries. 

2) Magneto-conversion: A hybrid anode design strategy in which an external magnetic field is applied to ferromagnetic transition-metal oxides used as conversion-type anode materials. This enables magnetic control over lithium-ion flux and nucleation within the electrode, improving uniformity and stability during cycling. 

3) Conversion-type: High-capacity anode materials in which metal oxides are converted into metallic nanoparticles and lithium oxide during charging. This conversion reaction allows lithium ions to be stored at capacities significantly higher than those of conventional intercalation-type anodes such as graphite. 

4) Lorentz force: The Lorentz force refers to the force experienced by a charged particle as it moves through an electric or magnetic field. In a magnetic field, an ion in motion experiences a force perpendicular to both its direction of travel and the direction of the magnetic field. This effect can be used to redistribute lithium-ion flux more uniformly within the electrode