@article {65, title = {Catalyst and electrolyte synergy in Li-O2 batteries}, journal = {Phys Chem Chem PhysPhys Chem Chem Phys}, volume = {16}, number = {7}, year = {2014}, note = {Gittleson, Forrest S
Sekol, Ryan C
Doubek, Gustavo
Linardi, Marcelo
Taylor, Andre D
eng
England
2014/01/11 06:00
Phys Chem Chem Phys. 2014 Feb 21;16(7):3230-7. doi: 10.1039/c3cp54555e. Epub 2014 Jan 10.}, month = {Feb 21}, pages = {3230-7}, abstract = {

Understanding the interactions between catalyst and electrolyte in Li-O2 systems is crucial to improving capacities, efficiencies, and cycle life. In this study, supported noble metal catalysts Pt/C, Pd/C, and Au/C were paired with popular Li-O2 electrolyte solvents dimethoxyethane (DME), tetraglyme (TEGDME), and dimethyl sulfoxide (DMSO). The effects of these combinations on stability, kinetics, and activity were assessed. We show evidence of a synergistic effect between Pt and Pd catalysts and a DMSO-based electrolyte which enhances the kinetics of oxygen reduction and evolution reactions. DME and TEGDME are more prone to decomposition and less kinetically favorable for oxygen reduction and evolution than DMSO. While the order of oxygen reduction onset potentials with each catalyst was found to be consistent across electrolyte (Pd \> Pt \> Au), larger overpotentials with DME and TEGDME, and negative shifts in onset after only five cycles favor the stability of a DMSO electrolyte. Full cell cycling experiments confirm that catalyst-DMSO combinations produce up to 9 times higher discharge capacities than the same with TEGDME after 20 cycles ( approximately 707.4 vs. 78.8 mA h g(-1) with Pd/C). Ex situ EDS and in situ EIS analyses of resistive species in the cathode suggest that improvements in capacity with DMSO are due to a combination of greater electrolyte conductivity and catalyst synergies. Our findings demonstrate that co-selection of catalyst and electrolyte is necessary to exploit chemical synergies and improve the performance of Li-O2 cells.

}, isbn = {1463-9084 (Electronic)
1463-9076 (Linking)}, doi = {10.1039/C3CP54555E}, author = {Gittleson, F. S. and Sekol, R. C. and Doubek, G. and Linardi, M. and Taylor, A. D.} } @article {70, title = {Controlled doping of carbon nanotubes with metallocenes for application in hybrid carbon nanotube/Si solar cells}, journal = {Nano LettNano Lett}, volume = {14}, number = {6}, year = {2014}, note = {Li, Xiaokai
Guard, Louise M
Jiang, Jie
Sakimoto, Kelsey
Huang, Jing-Shun
Wu, Jianguo
Li, Jinyang
Yu, Lianqing
Pokhrel, Ravi
Brudvig, Gary W
Ismail-Beigi, Sohrab
Hazari, Nilay
Taylor, Andre D
eng
Research Support, Non-U.S. Gov{\textquoteright}t
Research Support, U.S. Gov{\textquoteright}t, Non-P.H.S.
2014/05/02 06:00
Nano Lett. 2014 Jun 11;14(6):3388-94. doi: 10.1021/nl500894h. Epub 2014 May 13.}, month = {Jun 11}, pages = {3388-94}, abstract = {

There is considerable interest in the controlled p-type and n-type doping of carbon nanotubes (CNT) for use in a range of important electronics applications, including the development of hybrid CNT/silicon (Si) photovoltaic devices. Here, we demonstrate that easy to handle metallocenes and related complexes can be used to both p-type and n-type dope single-walled carbon nanotube (SWNT) thin films, using a simple spin coating process. We report n-SWNT/p-Si photovoltaic devices that are \>450 times more efficient than the best solar cells of this type currently reported and show that the performance of both our n-SWNT/p-Si and p-SWNT/n-Si devices is related to the doping level of the SWNT. Furthermore, we establish that the electronic structure of the metallocene or related molecule can be correlated to the doping level of the SWNT, which may provide the foundation for controlled doping of SWNT thin films in the future.

}, isbn = {1530-6992 (Electronic)
1530-6984 (Linking)}, doi = { 10.1021/nl500894h}, author = {Li, X. and Guard, L. M. and Jiang, J. and Sakimoto, K. and Huang, J. S. and Wu, J. and Li, J. and Yu, L. and Pokhrel, R. and Brudvig, G. W. and Ismail-Beigi, S. and Hazari, N. and Taylor, A. D.} }