We all know what it’s like to have your phone or laptop run out of power too quickly. And we would all be keen to see improved batteries, that can keep going longer and recharge faster!
It’s not just our devices that would benefit from better batteries. Electric vehicles are a more renewable and eco-friendly alternative to petrol and diesel, but have not yet become widespread. In order to make electric vehicles more viable and desirable, we need better lightweight batteries that can store a lot of charge, recharge quickly, and last for a long time.
Inside a battery, ions store charge in special materials at each electrode. It is these ions that produce an electric current when they move out of one electrode material and into the other one. In order to get faster-charging batteries, we need to be able to move the ions as quickly as possible in and out of the electrode materials. This is easier said than done, and it can be challenging to understand why the ions move more quickly through certain materials compared to others. Therefore, it is important to first understand the fundamentals of the ion transport processes in battery materials, and to identify what the slowest steps are. In my project, I use optical scattering microscopy to watch what happens to an electrode material inside a working battery. I shine visible light from a laser into the battery, through a small glass window. As the battery charges or discharges, the concentration of ions inside the material changes, which causes the amount of light that scatters back from the material to change too. This allows me to see how the ions move through the material and discover more about the ion transport processes.
NanoDTC Student, c2018