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A Korean research team has developed a new battery material by creating “atomic-scale pillars” inside cathode materials, enabling the material to maintain its structural integrity even after repeated charging and discharging.

The technology is expected to provide a new design principle for simultaneously improving the lifespan and safety of next-generation, high-energy-density electric vehicle batteries.

A research team led by Professor Changshin Jo of the Department of Chemical Engineering and Department of Battery Engineering at POSTECH (Pohang University of Science and Technology), together with Jiwoong Oh, a Ph.D. student in the Department of Battery Engineering, has recently developed a technology to stabilize the structure of high-nickel cathode materials, a key component of electric vehicle batteries.

The findings were recently published in the international journal Energy Storage Materials, which specializes in energy storage technologies.

It is no exaggeration to say that the performance of an electric vehicle battery depends heavily on its cathode material. Among them, high-nickel cathodes are considered a key material for electric vehicles and next-generation energy storage systems because they can store large amounts of energy with relatively small quantities of material.

However, increasing the nickel content can make the crystal structure unstable during repeated charging and discharging, ultimately causing the battery to degrade more rapidly.

In particular, when the battery is charged at a high voltage, the atomic arrangement inside the cathode contracts in one direction. This process can cause oxygen to escape and create microscopic cracks, leading to capacity loss and reduced safety.

Conventional approaches have attempted to stabilize the structure using elements with strong positive charges, such as molybdenum (Mo). 

However, these elements tend to accumulate mainly around the edges of cathode particles, leaving the inner regions largely unprotected.

It was essentially like reinforcing only the exterior walls of a building without strengthening its internal framework.

The research team took a different approach. Instead of reinforcing only specific regions, they developed a method to distribute structural support evenly throughout the entire cathode particle.

Using the cationic surfactant CTAB (cetyltrimethylammonium bromide), the team successfully dispersed molybdenum ions (Mo⁶⁺) uniformly throughout the cathode particles.

As a result, a structure known as cation anchoring was formed, in which nickel ions were regularly positioned between the lithium layers inside the cathode material.

These regularly arranged nickel ions act like pillars placed throughout a building, providing structural support at multiple points and restraining the lattice contraction that occurs during battery charging.

Analyses confirmed that this “atomic pillar” structure was formed uniformly throughout the entire particle rather than being limited to specific regions.

The cobalt-free (Co-free) high-nickel cathode material developed by the research team maintained its structural integrity even at high voltages and retained approximately 90% of its initial capacity after 300 charge-discharge cycles.

The material also significantly reduced gas generation caused by oxygen release, demonstrating improvements in both battery lifespan and safety.

The ability to develop long-lasting batteries without relying on cobalt, which is expensive and difficult to secure, represents promising news for the electric vehicle industry.

In other words, the technology opens up a pathway to reduce battery costs while simultaneously improving battery lifespan and safety.

Professor Changshin Jo stated, “Rather than simply adding new elements, we improved the stability of the material by precisely controlling the atomic arrangement within the cathode itself.”