Engineers identify key obstacle to longer-lasting batteries

Lithium nickel oxide (LiNiO₂) has emerged as a potential new material to power next-generation, longer-lasting lithium-ion batteries. Commercialization of the material, however, has stalled because it degrades after repeated charging.

University of Texas at Dallas researchers have discovered why LiNiO₂ batteries break down, and they are testing a solution that could remove a key barrier to widespread use of the material. They published their findings in the journal Advanced Energy Materials.

The team plans first to manufacture LiNiO₂ batteries in the lab and ultimately to work with an industry partner to commercialize the technology.

“The degradation of batteries made using LiNiO₂ has been a problem for decades, but the cause was not well understood,” said Dr. Kyeongjae Cho, professor of materials science and engineering in the Erik Jonsson School of Engineering and Computer Science and director of the Batteries and Energy to Advance Commercialization and National Security (BEACONS) program.

“Now that we have a clear understanding of why this happens, we’re working on a solution so the technology can be used to provide longer battery life in a range of products including phones and electric vehicles.”

The research is a project of UTD’s BEACONS initiative, which launched in 2023. The BEACONS mission is to develop and commercialize new battery technology and manufacturing processes; enhance the domestic availability of critical raw materials; and train high-quality workers for jobs in an expanding battery-energy storage workforce.

To determine why LiNiO₂ batteries break down during the last phase of charging, UT Dallas researchers analyzed the process using computational modeling. The study involved understanding chemical reactions and the redistribution of electrons through materials at the atomic level.

In lithium-ion batteries, electrical current flows out of a conductor called the cathode, which is a positive electrode, into an anode, a negative electrode. The anode typically is made of carbon graphite, which holds lithium at a higher potential. During discharge, the lithium ions return to the cathode through the electrolyte and send electrons back to the lithium-containing cathode, as an electrochemical reaction that generates electricity.

Cathodes typically are made of a mixture of materials that includes cobalt, a scarce material that scientists aim to replace with alternatives, including lithium nickel oxide.

The UTD researchers found that a chemical reaction involving oxygen atoms in LiNiO₂ causes the material to become unstable and crack. To resolve the issue, they developed a theoretical solution that reinforces the material by adding a positively charged ion, or cation, to alter the material’s properties, creating “pillars” to strengthen the cathode.

Matthew Bergschneider, a materials science and engineering doctoral student and first author of the study, has been setting up a robotics-based lab to manufacture battery prototypes to explore high-throughput synthesis processes of the designed pillared LiNiO₂ cathodes. The robotic features will assist with synthesizing, evaluating and characterizing the materials.

“We’ll make a small amount at first and refine the process,” said Bergschneider, a Eugene McDermott Graduate Fellow. “Then, we will scale up the material synthesis and manufacture hundreds of batteries per week at the BEACONS facility. These are all stepping stones to commercialization.”