MIT Nanoparticles

Egg-Like Nano Particles May Improve Battery Life

August 10, 2015 - Written By Jarrett Tennis

Smartphones have made major leaps in technology from their humble beginnings. We have had improvements in not only their size, but also their quality and durability of the screens. Processors are getting much faster, and some even rival full sized computers. Storage has expanded, memory has been added. They have gotten so good that some people even use theirs as their main internet connected device. But there has always been one major caveat, the battery. As devices grow more powerful they need more juice to make it through a day and in our quest to have the most portable and powerful devices available, we often find ourselves reaching for a charger to top up. A team of researchers at MIT and Tsinghua University in China have developed nano-sized “yolks” that may change all that.

When a normal Lithium-Ion battery goes through charging and discharging cycles the electrodes expand and contract, sometimes even doubling in size, which causes its outer layer to shed. This, in turn, uses up some of the lithium. That process leads to decreased performance and battery life. The researchers created egg-like electrodes that sport a titanium shell with an aluminum “yolk” that can change shape and expand without affecting the outer shell. What this means for us is new batteries that have higher capacity and longer life spans even when used with super fast charging like Qualcomm’s Quick Charge 2.0 technology.

This technology could easily have a lot of real-world impact far beyond our mobile devices. Electric cars. medical devices and robotics could all be impacted by this discovery, but the team stumbled upon it completely accidentally. They were experimenting with using aluminum nanoparticles for electrodes but discovered they had a naturally occurring oxidized layer of alumina. Because alumina is not a good conductor of electricity, they converted the layer into titanium using sulfuric acid and titanium oxide. After testing, the researchers concluded that the new electrodes were capable of storing more than three times the capacity of current graphite electrodes at normal charging speed. At very fast charging speeds the new egg-like electrodes still were able to outperform graphite. While these new titanium encased aluminum electrodes are not the only work being done in improving the humble battery but most of the other solutions are much more complicated. This process is simple, cheap, and easy, but there is no way to guarantee these batteries will make it to market in their current form.