A new manufacturing breakthrough from Penn State researchers could pave the way for safer, more efficient batteries for everything from smartphones to electric vehicles.
The team, led by engineering professor Hongtao Sun, has developed a method to create solid-state batteries using a low-temperature technique called “cold sintering.”
Most of today’s batteries, like those in your phone or laptop, are lithium-ion batteries that use liquid electrolytes to transfer energy between the battery’s two ends—the anode and the cathode.
While widely used, these liquid electrolytes are highly flammable and can lead to overheating or fires.
Solid-state batteries, which use solid electrolytes instead, offer a much safer and more stable option.
But they’re difficult to make, especially when ceramic materials are involved, because traditional methods require extreme heat—up to 1,000 degrees Celsius—which can damage or destroy other parts of the battery.
That’s where cold sintering comes in. This technique allows materials to be compressed and bonded together at much lower temperatures—around 150 degrees Celsius—by applying pressure and a small amount of liquid.
Sun’s team used this approach to create a new solid-state electrolyte by combining a ceramic material known as LATP with a polymer gel called PILG.
Ceramic materials like LATP are usually made up of many small crystals, with tiny gaps—called grain boundaries—between them.
These boundaries can block the flow of electricity, making the battery less effective. But by filling these boundaries with the PILG gel during the cold sintering process, the team created a “polymer-in-ceramic” composite that not only remains intact during manufacturing but also conducts electricity much more efficiently.
This new solid-state material doesn’t just conduct ions well; it also has a wider voltage range—0 to 5.5 volts—compared to traditional batteries, which typically operate between 0 to 4 volts.
That means it could power stronger, more energy-dense devices. Importantly, it also works well at room temperature, making it a practical option for everyday electronics.
Originally developed at Penn State in 2016, cold sintering was first applied to battery technology two years later. Sun’s work builds on that foundation, showing how it can be used to create complex battery components without the need for extreme heat.
Looking ahead, Sun hopes to scale up the technology for large-scale production and recyclability, which could make solid-state batteries not only safer and more powerful but also more sustainable.
The research team includes several Penn State graduate students and alumni and was recently published in the journal Materials Today Energy.
