Scientists in South Korea have made a major breakthrough that could improve the performance and lifespan of next-generation electric vehicle (EV) batteries.
Researchers at the Korea Institute of Energy Research have solved a persistent problem found in high-nickel (high-Ni) cathodes—materials that store energy in lithium-ion batteries and are essential for increasing EV range.
As more nickel is added to the battery’s cathode, the battery can hold more energy, which means longer driving distances.
High-Ni cathodes, which contain up to 80% nickel, are seen as vital for future electric vehicles. However, they come with a major drawback: the formation of unwanted lithium compounds, also known as residual lithium.
These compounds weaken the battery’s performance and complicate the manufacturing process.
Until now, it was widely believed that this residual lithium built up on the surface of the cathode particles.
Based on that assumption, manufacturers tried to wash it off with water or coat the surface to prevent the problem. But these methods didn’t fully work.
Even commercial batteries still suffer from performance issues caused by residual lithium.
In a surprising discovery, researchers Wooyoung Jin and Hyungyeon Cha found that these lithium compounds aren’t just on the surface—they also form deep inside the cathode material, hiding between the tiny particles that make up the whole structure.
This inner buildup, which had been overlooked for years, was found to be a major cause of the battery’s performance issues, including poor durability and structural weakening.
To uncover this hidden lithium, the team used advanced tools like high-resolution electron microscopes and electron energy loss spectroscopy.
These allowed them to closely examine the tiny internal spaces of the cathode material, where they discovered lithium crystallizing between particles in the gaps.
This buildup causes the battery materials to clump together in a gel-like state, leading to weaker bonds between components and less efficient performance.
Based on their findings, the researchers proposed using single-crystal high-nickel cathode materials instead.
These have a more solid, uniform structure with fewer gaps between particles, meaning there’s less space for residual lithium to form.
Their tests showed that this new material could reduce residual lithium by up to 54% compared to traditional cathode designs.
This new approach could help manufacturers produce more reliable and longer-lasting batteries—bringing us one step closer to affordable, high-performance electric vehicles.
According to the researchers, this discovery marks a turning point in battery technology and offers a promising path forward for both scientists and industry.
