For more than two decades, lithium-ion batteries have powered almost everything around us. They are inside smartphones, laptops, electric vehicles, drones, and even many medical devices. Batteries have improved a lot over the years. But they can still overheat, use expensive materials like cobalt, and are becoming harder to improve. Instead of developing a completely new battery, researchers at the California Institute of Technology (Caltech) are focusing on the one we already use. Their idea is to redesign its inside with 3D printing. And the team’s work focuses on one of the battery’s most important components: the cathode.
A Different Way to Build a Battery
Most lithium-ion batteries today are built with flat, layered electrodes. It is a design that has worked well for years because it is pretty easy to make. But the Caltech team is doing things differently. Instead of making a flat cathode, they designed and 3D printed one with a tiny, carefully engineered structure. So instead of moving through a flat layer, lithium ions can travel through a more complex 3D network. The researchers say this could help the battery store and deliver energy more efficiently.
That’s important because every time a battery charges or discharges, lithium ions have to travel between the electrodes. If that trip is shorter and smoother, the battery can work better.
“If you make a battery that is 3D architected instead of planar, every lithium ion is going to have an active surface available to it as it’s transporting through the electrolyte,” says Julia Greer, Professor of Materials Science, Mechanics and Medical Engineering at Caltech, whose lab has been working to improve Li-ion batteries.
Julia Greer, the Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering and executive officer for applied physics and materials science at Caltech. Image courtesy of EAS Communications Office/Caltech
According to the researchers, those extra surfaces give the ions more places to move, helping the battery transfer energy more efficiently than a traditional flat design.
The findings were published in the paper, “Structure–Transport Relationships in Microarchitected LiFePO4–Carbon Li Ion Battery Electrodes,” in ACS Energy Letters. The work was supported by the Defense Advanced Research Projects Agency (DARPA), NASA’s Jet Propulsion Laboratory through its President’s and Director’s Research and Development Fund, and Caltech.
Goodbye to Cobalt
One of the biggest changes is the material. The new battery component does not use cobalt, a metal found in many of today’s lithium-ion batteries. Cobalt is expensive, supplies are limited, and mining it has raised environmental and human rights concerns. Battery companies have spent years trying to reduce or replace it, and this research could help make that possible.
The team also changed how that battery component is made. Instead o
For more than two decades, lithium-ion batteries have powered almost everything around us. They are inside smartphones, laptops, electric vehicles, drones, and even many medical devices. Batteries have improved a lot over the years. But they can still overheat, use expensive materials like cobalt, and are becoming harder to improve. Instead of developing a completely new battery, researchers at the California Institute of Technology (Caltech) are focusing on the one we already use. Their idea is to redesign its inside with 3D printing. And the team’s work focuses on one of the battery’s most important components: the cathode.
A Different Way to Build a Battery
Most lithium-ion batteries today are built with flat, layered electrodes. It is a design that has worked well for years because it is pretty easy to make. But the Caltech team is doing things differently. Instead of making a flat cathode, they designed and 3D printed one with a tiny, carefully engineered structure. So instead of moving through a flat layer, lithium ions can travel through a more complex 3D network. The researchers say this could help the battery store and deliver energy more efficiently.
That’s important because every time a battery charges or discharges, lithium ions have to travel between the electrodes. If that trip is shorter and smoother, the battery can work better.
“If you make a battery that is 3D architected instead of planar, every lithium ion is going to have an active surface available to it as it’s transporting through the electrolyte,” says Julia Greer, Professor of Materials Science, Mechanics and Medical Engineering at Caltech, whose lab has been working to improve Li-ion batteries.
Julia Greer, the Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering and executive officer for applied physics and materials science at Caltech. Image courtesy of EAS Communications Office/Caltech
According to the researchers, those extra surfaces give the ions more places to move, helping the battery transfer energy more efficiently than a traditional flat design.
The findings were published in the paper, “Structure–Transport Relationships in Microarchitected LiFePO4–Carbon Li Ion Battery Electrodes,” in ACS Energy Letters. The work was supported by the Defense Advanced Research Projects Agency (DARPA), NASA’s Jet Propulsion Laboratory through its President’s and Director’s Research and Development Fund, and Caltech.
Goodbye to Cobalt
One of the biggest changes is the material. The new battery component does not use cobalt, a metal found in many of today’s lithium-ion batteries. Cobalt is expensive, supplies are limited, and mining it has raised environmental and human rights concerns. Battery companies have spent years trying to reduce or replace it, and this research could help make that possible.
The team also changed how that battery component is made. Instead o