Hu R.,Alan G Macdiarmid Nanotech Institute |
Baratunde A Cola,University of Texas at Dallas |
Haram N.,Georgia Institute of Technology |
Barisci J.N.,Alan G Macdiarmid Nanotech Institute |
And 14 more authors.
Nano Letters | Year: 2010
Low efficiencies and costly electrode materials have limited harvesting of thermal energy as electrical energy using thermo electrochemical cells (or "thermocells"). VVe demonstrate chermocells, in practical configurations (from coin cells to cells thai can be wrapped around exhaust pipes), that harvest low-grade thermal energy using relatively Inexpensive carbon multiwalled nanotube (MWNT) electrodes. These electrodes provide high electrochemically accessible surface areas and fast redox-mediated electron transfer, which significantly enhances thermocell current generation capacity and overall efficiency. Thermocell efficiency is further improved by directly synthesizing MWNTs as vertical forests that reduce electrical and thermal resistance at electrode/substrate junctions. The efficiency of thermocells with MWNT electrodes is shown to be as high as 1.4% of Carnot efficiency, which is 3-fold higher than for previously demonstrated thermocells. With the cost of MWNTs decreasing. MWNT-based thermocells may become commercially viable for harvesting low-grade thermal energy. © 2010 American Chemical Society.