Improving Rechargeable Batteries with Novel Nanoparticle

August 6, 2015

Category: Science & Technology Posted:02:07PMAuthor: Guest_Jim_*

Since they entered the commercial market, lithium-ion batteries have proven themselves to be invaluable for mobile technologies, but sadly improving them has been difficult. This is because many possible ways to improve them have serious flaws, such as reduced lifespans and fire dangers. Researchers at MIT and Tsinghua University have recently developed a nanoparticle that could significantly improve batteries, without the problems.

One way to improve lithium-ion batteries is to change the materials used as electrodes. Currently graphite is used for the anode, and it can store about 0.35 ampere-hours per gram (Ah/g), but other materials have much higher charge storage capacities, like aluminum at 2 Ah/g. The issue with aluminum, and many other materials, is that it swells so much when it receives lithium ions that it could cause electrical contacts to disconnect and damage the electrolyte. What the researchers have done to address this problem is create yolk-shell nanoparticles of aluminum and titanium-oxide. In this configuration, the aluminum yolk is free to swell within the shell, as there is plenty of separation between the yolk and the shell, unlike core-shell nanoparticles where the components are bonded together. The new nanoparticles have a charge capacitor of 1.2 Ah/g at a normal charging rate, and 0.66 Ah/g when charged six times faster than normal, after 500 charge-discharge cycles.

The researchers actually created the nanoparticles by accident when they were processing aluminum particles and found the aluminum shrunk within the titanium-oxide shell they formed around it. This is actually very good news too, because the process is so simple it is easily scalable.

Source: MIT