| dc.description.abstract | In this thesis a thermoelectric cell is developed. Aligned Carbon Nanotubes
and aligned Nitrogen-doped Carbon Nanotubes are used as electrode materials.
Ferri/Ferrocyanide and Tetrabutylammonium Nitrate (TBAN) electrolytes
have been tested for thermoelectric performance, with the two different electrode
materials. It was found that Nitrogen doping of CNT's enhances reaction kinetics
of the Ferro/Ferricyanide redox reaction. It is suggested that there will be an ideal
level of doping, where the electron transfer rate is maximized.
TBAN showed the highest open circuit voltage, but it was discovered that
TBAN in dodecanol was unsuitable as an electrolyte for thermocells due to low
conductivity and unstable current. The current decreased to less than 1 A in
some seconds.
The highest thermoelectric eciency obtained was for a symmetric NCNT elec-
trode conguration, with the Ferrocyanide redox couple. The eciency was 0.007
% of the Carnot efficiency, which is less than state-of-the art electrolyte thermo-
cells. The lower eciecy was due to non-optimized electrodes and current leakages
in the test cell.
Dense, uniform and aligned CNT's were grown on Aluminum foil but using a
pre-deposited 2 nm layer of iron catalyst. Ammonia annealing was required before
CVD. The treatment with ammonia lead to longer catalyst lifetimes and better
alignment. Lengths up to 110 m was obtained, 15 nm in diameter.
Growth of aligned N-doped CNT's on Aluminum was done using a
floating catalyst method. Up to 1.5 % incorporation of Nitrogen was achieved. | |
