Scientists have taken a major step toward faster-charging and longer-lasting batteries — a breakthrough that could power the next generation of electric vehicles.
Engineers at the University of California San Diego, together with collaborators from UC Irvine, UC Santa Barbara, and LG Energy Solution, have developed a new design for metal alloy electrodes that could dramatically improve the performance and lifespan of solid-state batteries.
The research, published in Nature Communications, focuses on the use of a lithium-aluminum alloy for the negative electrode, also called the anode.
This alloy contains two distinct forms, or “phases,” known as the lithium-rich beta phase and the lithium-poor alpha phase.
The scientists discovered that the way lithium ions move through these phases plays a crucial role in determining how efficiently a battery can charge and discharge.
By carefully adjusting the ratio of lithium to aluminum, the researchers were able to create an electrode with more of the beta phase.
This change turned out to be a game-changer. Lithium ions could move through the beta phase up to ten billion times faster than through the alpha phase, allowing for much quicker energy transfer.
The beta phase also made the electrode denser and more stable, improving how lithium travels between the electrode and the solid electrolyte — a key part of solid-state battery design.
In laboratory tests, batteries built with these optimized lithium-aluminum electrodes charged and discharged rapidly and retained their performance through more than 2,000 cycles, showing remarkable durability.
“This is the first study to directly link how the distribution of the beta phase affects lithium movement inside the alloy,” said the research team. “It provides a clear roadmap for developing better electrode materials that combine speed, stability, and efficiency.”
Solid-state batteries are widely seen as the future of electric vehicles and portable electronics because they replace the flammable liquid electrolyte found in today’s lithium-ion batteries with a solid material.
This makes them safer, more compact, and capable of holding more energy. However, one of the biggest challenges has been designing electrodes that can handle repeated charging and discharging without degrading.
By uncovering how to harness the beta phase of lithium-aluminum alloys, the UC San Diego team may have found a way to overcome this limitation. The discovery could bring solid-state batteries much closer to commercial reality — enabling electric cars that charge in minutes and last for many years.
Source: UC San Diego.
