The U.S. Department of Energy's Argonne National Laboratory has announced a new design for lithium-ion batteries that enhances performance and reduces costs. This development is expected to accelerate the adoption of electric vehicles (EVs) and grid energy storage, aiding global decarbonization efforts.
In 2012, Argonne researchers advanced lithium-ion battery technology with a novel cathode material that increased energy density and durability. They fine-tuned the composition of nickel, manganese, and cobalt in cathode particles to leverage the beneficial characteristics of these metals.
"This breakthrough material represents an across-the-board improvement for batteries," stated Khalil Amine, Argonne Distinguished Fellow and leader of Argonne’s Advanced Battery Technology team. "It features higher storage capacity, robust stability and heat tolerance at high voltages, and longer lifetimes."
Argonne's new design employs a dual-gradient approach where nickel concentration decreases from the particle core to its surface. This aims to maximize energy density while minimizing reactivity. The cathode particles possess a layered structure typical of commercial batteries today.
"For EVs to replace gasoline-powered vehicles on a global scale, batteries must be able to operate at higher voltages," said Amine. High-voltage operation can degrade cathodes by causing them to crack or react with electrolytes, which move lithium ions between electrodes.
To address this issue, Argonne added another layer to its design: fabricating cathode particles with a gradual transition from disordered material on the surface to ordered material in the core. This approach combines different compositions into one particle for high capacity and stability at high voltages.
Tests conducted using X-ray techniques confirmed that the fabrication successfully produced stable cathode particles during high-voltage operation. "We proved that the disordered particle surface is indestructible," said Tongchao Liu, lead author of the study published in Nature Energy.
The new design significantly reduced cobalt content—a scarce and costly resource—while enhancing heat tolerance crucial for safe operations at high voltage. "We plan to reduce the cobalt level down to 1%," noted Amine.
This study marks the first combination of composition and structure gradients in a single cathode particle, potentially inspiring further research into integrating different structures for improved battery performance.
"This breakthrough material represents an across-the-board improvement for batteries," reiterated Amine. "Our patented design is ready to be licensed by industry."
This research was supported by DOE’s Vehicle Technologies Office with contributions from various scientists including Lei Yu, Junxiang Liu, Alvin Dai among others.