TodayToday's edition
A KAIST liquid-crystal polymer separator let a lithium-metal cell hold 94% of its capacity after 100 cycles at 4C, but it is a lab test with no cell size, cost or product date given.
Science DeskEdited by Ege Erten
3 min readAI-assisted
In KAIST's lab test, a lithium-metal cell with the vertically aligned separator kept 94% of its capacity after 100 cycles at 4C.
Illustration (AI-generated)
KAIST researchers have built a battery separator whose molecules line up like lanes on a road, and a lithium-metal cell fitted with it kept 94% of its initial capacity after 100 charge-discharge cycles at a 4C charging rate. The university announced the work on Nov. 9, 2026.
The team is led by chemistry professors Dong Ki Yoon and Hye Ryung Byon at the Korea Advanced Institute of Science and Technology (KAIST). The paper, "Directional Li+ Flux Control via Liquid-Crystalline Polymer Separators for Fast-Charging Lithium Metal Batteries," appeared in the journal ACS Nano; KAIST's release dates it to September 2026, while its EurekAlert record lists Oct. 13, 2026. Geunjung Lee and Rak Hyeon Choi are the co-first authors.
For anyone who charges a phone or an electric vehicle, the point is speed without wear. KAIST says 4C is a rate at which a battery can in theory be fully charged in about 15 minutes, based on its rated capacity. That is a theoretical figure for the rate, not a measured charge time reported for this cell.
A lithium-metal battery uses lithium metal as its anode and can store more energy than a conventional lithium-ion cell. During fast charging, however, lithium can pile up in sharp, branch-like deposits called dendrites. These shorten battery life, can damage the separator between the electrodes and, in the worst case, cause internal short circuits and fire, according to the KAIST release and NOCUTNEWS.
The team used liquid crystals, materials that combine the ordered structure of a solid with the flow of a liquid. Because their molecular orientation can be changed by surface treatment, the researchers could choose it. They made a porous separator from a liquid-crystalline polymer with nanometer-scale pores and added polyethylene glycol (PEG) chains, which help lithium ions move.
They then aligned the molecules either vertically or horizontally and compared the results. With vertical alignment, ions travel straight toward the electrodes instead of detouring. That cut the tortuosity, a measure of how winding the ion path is, by about 2.5 times against the horizontal version. KAIST says ions then moved faster and more evenly, which suppressed dendrite growth and improved stability.
The headline number comes from one lab test: 94% capacity retained after 100 cycles at 4C in a lithium-metal battery. The sources give no cell size, cell count, cathode or energy density, so the result says nothing yet about how the separator behaves in a large pack. Interesting Engineering, which also covered the work, noted that further tests will show whether it works in larger batteries.
For data centers and grid storage, the finding is background rather than a supply change: the sources name no battery maker testing the separator, and KAIST gives no date for a product. Lithium-metal cells matter because more energy per kilogram means lighter packs, but 100 cycles is a short test. Voltgrid has reported on a Korean manganese-rich cathode that was tested over 200 cycles, a similar lab-scale step.
KAIST has not said whether the separator can be made at scale, what it would cost or whether a battery maker is testing it. Yoon said only that the team expects the approach to contribute to high-energy-density next-generation batteries for long range and fast charging. The work was supported by South Korea's Ministry of Science and ICT, the National Research Foundation of Korea and the GIST InnoCORE Program.
