Lithium-ion batteries power nearly every piece of modern technology and gadgetry we use on a daily basis. They power electric vehicles, cell phones, laptops, and tablets. For years, the development and design of the gadget depended on the size and shape of available battery types.
A team of researchers from the American Chemical Society made a way to create customized lithium-ion batteries via 3D printing. This innovative system could mean a variety of new gadgets in sizes and shapes the public hasn’t seen before.
Current lithium-ion restrictions
Researchers Christopher Reyes, Benjamin Wiley, and their colleagues noticed most lithium-ion batteries on the market are either cylinders or rectangles in shape. These traditional shapes mean developers like Apple, Toshiba, or Samsung have to keep the shape of the lithium-ion battery in mind first when developing the next smartphone or computer. It also means there’s an inevitable amount of wasted space inside the device caused by the battery.
There’s also a size restriction as to how small effective lithium-ions can get. While the batteries can get small, there still has to be enough room inside them for the electrolytes, anode and cathode materials, and carbon additives.
3D printing a solution to lithium-ion sizes
The ACS team could theoretically 3D print an entire device -- battery included -- in any shape. The printing process wasn’t the problem. The issue came from the polymers used in 3D printing technology. Polymers like polylactic acid (PLA) aren’t ionic conductors. To keep costs low, the researchers had to find a way to create the custom lithium-ion batteries on inexpensive, relatively standard 3D printers.
The researchers developed a way to boost the conductivity of PLA. They infused it with an electrolyte solution and added graphene or carbon nanotubing into the anode or cathode, respectively. Adding the graphene and carbon nanotubing improved the battery’s conductivity.
To test their solution, they created a simple LED bangle bracelet that looked like a Fitbit or activity tracker. The bangle’s LEDs were powered by a lithium-ion battery integrated into the bangle. The battery lit green LED for nearly a minute -- a low capacity for people accustomed to the length of an iPhone battery’s charge.
The researchers admitted the first round of 3D printed batteries are two times lower than the power of commercial lithium-ion batteries. While the process is impressive, the battery itself is still too low for commercial and practical use. However, the researchers have the process finalized, and they’ve already got several ideas to increasing capacity. They’ll try replacing the PLA materials with new materials like 3D-printable pastes.
No word from the researchers as to whether the 3D printed batteries avoid their tendency to overheat and even catch flame. Last year, a separate team of researchers from the University of Maryland developed a water-based lithium-ion battery they said was incapable of sparking a potentially dangerous flame.