It’s that time of year when I give my final year solid state chemistry lectures. I find this the most interesting of all the modules I teach, not just because it is slightly related to my research, but also because of all the exciting work that’s being done in this field.
This year I’ve updated the section on lithium ion batteries, and added a section on transparent conducting oxides (TCOs).
For lithium ion batteries, much research is being done into making better electrode materials by using nanoporous structures; for example the use of carbon ‘sponges’ for anodes, replacing the traditional graphite materials. An example of this approach can be found here. Cathode materials are not being neglected either, and an example which uses spherical nanoporous LiCoPO4/C composites can be seen here.
Turning to TCOs, I’ve always found them very interesting materials, combining transparent and conducting properties, which at first sight might seem to be mutually exclusive! I’ve chosen to concentrate on indium tin oxide, in which transparent, non-conducting indium oxide is made into a conductor by doping with tin. The conduction occurs because the tin levels form a donor band which is close to the conduction band (or even overlapping it), making it possible for electrons to reach the conduction band, but (very importantly), not affecting the band gap. There is an excellent paper by Peter Edwards and co-workers which explains the chemistry and physics of these materials very clearly. The many applications of TCOs in flat panel displays, solar panels and smart windows are so important for developing technologies that I feel that no solid state chemistry course should be without at least a mention of them!
Of course, it remains to be seen how the lectures are received, but I hope that the information presented will be seen to be interesting. Next year I aim to add lithium-air batteries, but there was no space for them this year!