# KAIST separator with aligned liquid crystal polymer keeps 94% capacity after 100 cycles at 4C

- Published: 2026-11-09 00:02 UTC
- Section: Power & Energy › Batteries
- Tags: KAIST battery separator, lithium metal battery, liquid crystal polymer separator, lithium dendrites, fast charging 4C, ion path tortuosity, polyethylene glycol chains, electric vehicle battery, ACS Nano
- URL: https://realtech.media/news/rt-b8144d11477c751aaced77a5_kaist_separator_with/

**KAIST chemists aligned liquid crystal polymer molecules in a lithium metal battery separator, cutting ion path tortuosity about 2.5 times and suppressing dendrites.**

![KAIST separator with aligned liquid crystal polymer keeps 94% capacity after 100 cycles at 4C](https://realtech.media/media/2026/11/6c26f157e4c5f4cd.jpg)
*biz.heraldcorp.com*

A joint team of Professors Yoon Dong-ki and Byun Hye-ryeong from the Department of Chemistry at KAIST developed a battery separator in which the molecular alignment of a liquid crystal polymer is controlled to speed up lithium-ion transport and improve stability. KAIST announced the result on the 9th, according to biz.heraldcorp.com. [1]

## The dendrite problem in lithium metal cells

Lithium metal batteries can store more energy than conventional lithium-ion cells, which is why they are considered candidates for next-generation electric vehicle batteries. Their commercialization is held back by dendrites: needle-like lithium growths that form during charging. [1]

Dendrites shorten battery life and damage the separator, which can cause an internal short circuit and fire. The risk grows during fast charging, when lithium deposits unevenly. [1]

## Aligned channels in the separator

The team set out to change the path of lithium ions so that they move straight and uniformly toward the electrode instead of along a winding route. To do this, they made a liquid crystal polymer separator with pores a few nanometers across and introduced polyethylene glycol (PEG) chains that assist ion movement. The liquid crystal molecules were then aligned vertically, which straightened the channels for the ions. [1]

The vertically aligned separator had about 2.5 times lower tortuosity of the ion path than a horizontally aligned one. According to the report, ions moved faster and more evenly, and dendrite formation was effectively suppressed. [1]

When the separator was used in a lithium metal battery, the cell retained 94% of its initial capacity after 100 charge-discharge cycles at 4C, which corresponds to a theoretical 15-minute charge. [1]

The approach improves charging performance and stability by controlling molecular alignment inside the separator without changing the battery materials themselves. For commercial use, the report notes that large-area separator manufacturing and long-term durability verification are still required. [1]

Professor Yoon said the work showed that controlling the alignment of liquid crystal polymers can be used to design lithium-ion pathways efficiently and improve battery performance and stability. The results were published in the September issue of ACS Nano. [1]

## Sources

1. [biz.heraldcorp.com](https://biz.heraldcorp.com/article/10929974)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-b8144d11477c751aaced77a5_kaist_separator_with/