(592g) From Thermopower Waves to Asymmetric Chemical Doping – New Concepts in Energy Storage and Generation Using Molecular Interactions with Single-Walled Carbon Nanotubes

Authors: 
Liu, A. T., Massachusetts Institute of Technology
Mahajan, S. G., Massachusetts Institute of Technology
Kunai, Y., Massachusetts Institute of Technology
Cottrill, A. L., Massachusetts Institute of Technology
Strano, M., Massachusetts Institute of Technology
There is a pressing need to find alternatives to conventional energy generation techniques, specifically those that rely on elements in finite global supply. Thermopower wave (TPW) devices, which convert chemical to electrical energy by means of self-propagating reaction waves guided along nanostructured thermal conduits, have the potential to address this demand.1 We show that conversion efficiency can be increased significantly by selecting molecules such as sodium azide or sucrose with potassium nitrate to offset the inherent penalty in chemical potential imposed by strongly p-doping chemicals,2 a validation of the predictions of Excess Thermopower theory.3 Such chemical-potential-gradient-induced-electricity can be further exploited in a more direct manner, decoupled completely from the combustion reactions, affording another novel energy generation scheme using only molecular interactions, and subsequent charge transfers, with single-walled carbon nanotubes.4 Specifically, we demonstrate that chemically-modified carbon nanotube fibers enable unique power sources driven entirely by a chemical potential gradient.5 Short circuit electrical current (11.9 μA mg−1) and open circuit potential (525 mV) are reversibly produced by localized acetonitrile doping under ambient conditions. An inverse length-scaling of the maximum power as L−1.03 that creates specific powers as large as 30.0 kW kg−1 highlights the potential for microscale energy generation.

(1) Choi, W.; Strano, M. S. et. al. Nat Mater 2010, 9.

(2) Mahajan, S. G.; Liu, A. T.; Strano, M. S. et. al. Energy & Environmental Science2016, 9, 1290.

(3) Abrahamson, J. T.; Strano, M. S. et. al. ACS Nano 2013, 7, 6533.

(4) Kunai, Y.; Liu, A. T.; Strano, M. S. et. al. J. Am. Chem. Soc. 2017, 139, 15328.

(5) Liu, A. T.; Kunai, Y.; Strano, M. S. et. al. Adv. Mater. 2016, 28, 9752.