Magnetic control of lithium enables a safe, explosion-free 'dream battery' - Energy & Green Tech - Hi Tech & Innovation

Schematic of a magneto-conversion anode design for high energy density and dendrite-free hybrid lithium-ion/lithium-metal batteries. Credit: POSTECH

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 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" strategy that applies an external magnetic field to ferromagnetic manganese ferrite conversion-type anodes.

The study has been published in Energy & Environmental Science.

Challenges in battery safety and capacity

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.

Operando X-ray microscopy and computational modeling revealing the real-time dynamic behavior of lithium deposition. Credit: POSTECH

How the magneto-conversion strategy works

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—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.

Implications for next-generation batteries

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.

"We expect this technology to serve as a foundation for improving capacity, cycle life, and charging speed in next-generation batteries." 

Provided by Pohang University of Science and Technology 

by Pohang University of Science and Technology

edited by Sadie Harley, reviewed by Robert Egan 

Source: Magnetic control of lithium enables a safe, explosion-free 'dream battery'