Abstract
Several governments are committed to fight against climate change and, reducing the pollution derived from the utilization of fossil fuel powered cars is considered as a part of the solution. Therefore, environmentally friendly electric vehicles (EVs) keep on gaining importance[1], [2]. Nevertheless, in order to extend the autonomy range of EVs to that achieved by internal combustion cars, next-generation lithium-ion batteries (LIBs) with larger specific capacities and subsequent higher energy densities are required.
Replacing graphite, the anode widely used in current LIBs, with other materials capable of providing much larger capacities, is a well-known strategy to boost the specific capacity of this technology[3], [4]. In this sense, silicon is one of the most promising materials, not only because it can deliver a capacity (~3579 mAh/g) approximately 10 times that of graphite (~370 mAh/g)[5], [6] , but also because it is an affordable substitute anode material for LIBs, since it is the second most abundant element in the earth's crust[7].
Numerous scientific investigations have been carried out in silicon anodes for LIBs, however, a parameter that has not been assessed and would be crucial in its real performance in EVs is the effect that temperature would have over its cyclability. To determine such effect, we have conducted galvanostatic tests with silicon-based and silicon-rich anodes in half-cells at different temperatures. Besides, the absence or presence of fluoroethylene carbonate (FEC) as electrolyte additive has also been evaluated. The different capacities and cycle-lifes observed, along with the possible kinetic mechanisms behind them, will be here discussed.
We gratefully acknowledge support from the U. S. Department of Energy (DOE), Vehicle Technologies Office. Argonne National Laboratory is operated for DOE Office of Science by UChicago Argonne, LLC, under contract number DE-AC02-06CH11357. The U.S. government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the government.
[1] M. Armand and J-M. Tarascon. Nature 2008, 451, 652-657. Building better batteries.
[2] C. C. Chan. EEE 1999 International Conference on Power Electronics and Drive Systems, PEDS'99, Hong Kong. The Past, Present and Future of Electric Vehicle Development.
[3] W-J. Zhang, J. Power Sources 2011, 196 (1), 12-24. A review of the electrochemical performance of alloy anodes for lithium-ion batteries.
[4] V. Etacheri, R. Marom, R. Elazari, G. Salitra and D. Aurbach. Energy Environm. Sci. 2011, 4, 3243-3262. Challenges in the development of advanced Li-ion batteries: a review.
[5] X. Su, Q. Wu, J. Li, X. Xiao, A. Lott, W. Lu, B. W. Sheldon and J. Wu. Adv. Energy Mater. 2014, 4, 1300882. Silicon-Based Nanomaterials for Lithium-Ion Batteries: A Review.
[6] H. Wu and Y. Cui. Nanotoday 2012, 7(5), 414-429. Designing nanostructured silicon anodes for high energy lithium ion batteries.
[7] U. Kasavajjula, C. Wang and A. J. Appleby. Journal of Power Sources 2007, 163, 1003. Nano- and bulk-silicon-based insertion anodes for lithium-ion secondary cells.