The capacitor is often overshadowed by the transistor when it comes to computer components. However, lately we’ve seen how motherboard manufacturers have been moving from analog fluid-based capacitors to digital solid-state capacitors. These have a superior life expectancy and improved performance compared to the older analog versions, but then again a bit more expensive. Researchers at Georgia Institute of technology have spent a lot of time studying barium titanate and have been able to manufacture capacitors with twice the capacity by mixing the barium titanate with a polymer matrix.
This isn’t the first time we hear about barium titanate. The last we heard was that researchers was using the metallic complex to designing revolutionizing batteries in the form of a ultra capacitor system and what Joe Perry and Philseok Kim have done is quite similar.
The problem with barium titanate is that a dispersion of molecules have an uneven distribution, but they’ve been able to work around through a organic capsule with phosphonic acid (R-H2PO3). This resulted in a uniform dispersion.
“Our team has developed nanocomposites that have a remarkable combination of high dielectric constant and high dielectric breakdown strength,” – Joseph W. Perry, professor at Georgia Tech School of Chemistry and Biochemistry and the Center for Organic Photonics and Electronics. “For capacitors and related applications, the amount of energy you can store in a material is related to those two factors.”
The material has been tested and verified at up to 1MHz and is believed to handle higher frequencies. According to the researchers the big breakthrough isn’t the storage capacity but how they’ve been able to encapsulate the barium titanate complex and the approach could be used with other nanoparticles. It’s far from easy to create homogeneous solutions with a high density with aggregates, which is quite common with barium titanate. No one has been able to create a capsule that solves and is capable of handling some stress.
The organic phosphonic acids also made the barium titanate a lot more compatible with the polymer matrix which in turn results in the dielectric. The researchers is considering a commercialization and applied for a patent of the method, which in turn strengthens a possible commercial product. There are many other areas where dielectrics are used, not just capacitors.
The article “High Permittivity and High Dielectric Strength Nanocomposites via Surface Modification of BaTiO3 with Functional Phosphonic Acids” is published in Advanced Material Vol 19, issue 7 and online here.
