Abstract
Although the 100% electric car is a promising option for the future, the present technologies do not offer efficient batteries in order to provide higher range then a classic thermal engine car. For the next years compromises like hybrid cars will cover significant percentage of the market. Today technology allows us for example to recover energy from braking and its transformation in electricity; however the residual heat from the engine and exhaust pipe is not converted in useful electric energy. One solution for the convertion of heat into electric power is given by the thermoelectric materials. The limited presence of TE devices on the marketplace is mainly the result of low thermoelectric figures of merit (ZT) for known TE materials. A practical TE material should combine high Seebeck coefficient, high electrical conductivity and low thermal conductivity. The last decade experienced a dramatic increase of thermo-electrical conversion efficiency due to the quantum confinement effect characterizing nano-bulk superstructures. Those structures are available now using a top down approach like mechanical alloying using ball milling technique or bottom up path by means of chemical methods.The nano-bulk superstructures are more flexible in terms of coating uneven surfaces (with the option for proper ligands) making them suitable candidates for heat recovery of internal combustion engines.
Keywords: nanotechnology, thermoelectric materials, Seebeck effect, figure of merit, heat recovery