Column: Electric dreams turn into a nightmare for battery metals
A sector that was once racing to build new supply has been closing mines and deferring projects as low prices bite into the cost curve.
A team from Florida State University and the Lawrence Berkeley National Laboratory has developed a new strategy to build solid-state batteries that are less dependent on specific chemical elements, particularly expensive metals with supply chain issues.
In a paper published in the journal Science, the researchers demonstrated that a mix of various solid-state molecules could result in a more conductive battery that was less dependent on a large quantity of an individual element.
“There’s no hero element here,” lead researcher Bin Ouyang said. “It’s a collective of diverse elements that make things work. What we found is that we can get this highly conductive material as long as different elements can assemble in a way that atoms can move around quickly. And there are many situations that can lead to these so-called atom diffusion highways, regardless of which elements it may contain.”
Solid-state batteries operate almost the same way as other batteries—they store energy and then release it to power devices. But rather than liquid or polymer gel electrolytes found in lithium-ion batteries, they use solid electrodes and a solid electrolyte. This means that a higher energy density can occur in the battery because lithium metal can be used as the anode.
Additionally, they have lower fire risk and potentially increase the mileage of electric vehicles.
However, many of the batteries constructed thus far are based on critical metals that are not available in large quantities.
The research team considered the straightforward path of using one element to replace commonly used ones, but that approach raised its own supply chain issues. Instead, the team addressed the problem by designing materials that weren’t beholden to one specific element. For example, instead of creating a battery made with germanium, which rarely appears naturally in high concentrations, the team created a mixture of titanium, zirconium, tin, and hafnium.
“With such a feature, we need to assemble those elements in a way so that we have many ‘good’ local configurations which can form a network for the fast transport of atoms or energy,” Ouyang said. “Think of it as a highway. As long as there is a connected highway for atom diffusion, the atoms can move quickly.”
The scientist noted that this study opened a new area of research for him and his colleagues as they work to build more efficient solid-state batteries.
