The Difficulties with Working with Nanoparticles
Phil Kinnane May 21, 2012
I was just reading one of my favorite sites, phys.org, about the difficulties of working with nanostructures. In the world of batteries, you want to maximize charge, while minimizing volume and weight. This means that the nano-world is starting to take hold, but, as has been discovered with many other applications where nanotechnology is being applied, it is very difficult to control the material properties in this world.
Lithium-ion batteries commonly use graphite as the material for the negative electrode (during discharge). The article describes research performed by a group from Stanford University that instead uses silicon as the electrode material, as it can hold up to ten times as much charge as graphite. They hope to produce lithium-ion batteries that are double the energy density as today’s batteries. Yet, silicon is a much more fragile or brittle material than graphite at these sizes, and does not survive the charging and discharging required of such a battery.
In the world of modeling, nanoparticles can also be difficult to work with. The above example is of a typical particle that Professor Zho’s research group at IUPU in Indianapolis wanted to model in their lithium-ion battery. They were able to create a mesh from an image of this nanoparticle, and bring this into COMSOL Multiphysics, but then what? How do you define the different parts of the particle?
A new feature in version 4.3 now allows them to work with such meshes and specifically select regions of elements to belong to a group where a domain or boundary setting can then be defined. Known as Mesh Selection, this will open up a world of possibilities to those that work with image-to-mesh generating programs, such as Simpleware and Mimics.
The group in Stanford worked with their nanoparticles for five years and is now starting to see good results. We wish them all success.