The Advanced Energy Materials Laboratory focuses on using nanostructured materials to improve energy conversion technologies. In short, we hope to solve big energy problems by thinking small. Why does thinking small provide such promise? The answer comes from a deeper understanding of the fundamental principles involved in energy conversion. Devices such as fuel cells, solar cells, and thermoelectrics produce electricity by converting a primary energy source (a fuel, light, or heat) into a flow of electrons. This conversion necessarily involves an energy transfer step, where energy from the source is passed along to the electrons constituting the electric current. This transfer has a finite rate and must occur at an interface or reaction surface. Thus, the amount of electricity produced scales with the interfacial area available for the energy transfer. Unsurprisingly, then, the desire for large surface areas has led to the use of nanomaterials.
Despite the successes brought about by the incorporation of nanostructured materials in fuel cells, solar cells, and other devices, we are still far away from possessing a solid understanding of what is really going on at the nanoscale. Many critical questions remain. For example:
- What are the dimensions over which energy transfer or charge transfer reactions can effectively occur?
- Is there such a thing as too small? If the periodicity of a nanostructured materials interface is smaller than the characteristic energy transfer dimension, the answer may be yes.
- How do kinetic properties scale at small dimensions-is there more than simple surface area scaling at work?