Metal Oxide/Reduced Graphene Oxide Anodes for Lithium-Ion Batteries

Lithium-ion batteries have become the most popular power source for portable electronics, offering very good energy density, along with favorable stability and efficiency [1]. At the Li-ion anode, graphitic carbons have been ubiquitous [2], though these materials may lack sufficient energy density to enable grid or home-scale energy storage or the realization of fully electric vehicles with sufficient driving range.  Therefore, recent years have seen a shift in focus to the development of materials with higher capacity than graphite. 

Metal oxides are a promising family of materials that could potentially replace graphite as the anode in lithium-ion batteries. Metal oxides typically do not intercalate lithium during charging process, but rely on chemical transformations with more than one electron transfer to store and deliver energy, which results in much higher capacities.  In addition, they also have a safer lithiation potential that eliminates the problematic lithium plating process during charging.  However, the use of metal oxides has been limited mainly by their low electrical conductivity, and inferior cycling stability [3-5]. To circumvent these challenges, nanostructured metal oxides and their composites with advanced carbon materials, such as graphene, can be used to improve their capacity retention by suppressing phase segregation during charge/discharge and volumetric expansion, as well as enhancing ionic and electronic transport.

In this work, the interaction between metal oxides (Co₃O₄, SnO₂, NiO, MnO₂) and several carbon substrates was explored using a combination of electrochemical and physical characterization.  Increased interfacial interaction between carbon and metal oxide, while minimizing the carbon loading, is critical to improve battery performance. Excellent capacity retention and rate capability can be realized through a combination of material chemistry and structure, and promising approaches to achieve this will be the focus of this presentation. 

[1] Tarascon. J, Armand. M, Nature, 414 (2001) 359.

[2] Sawai. K, Ohzuku. T, J. Electrochem. Soc., 150 (2003) A674.

[3] Lee, S. H.; Kim, Y. H.; Deshpande, R.; Parilla, P. A.; Whitney, E.; Gillaspie, D. T.; Jones, K. M.; Mahan, A. H.; Zhang, S. B.; Dillon, A. C., Adv. Mater., 20 (2008) 3627.

[4] N.S. Spinner, A. Palmieri, N. Beauregard, L. Zhang, J. Campanella and W.E. Mustain, J. Power Sources, Accepted.

[5] N. Spinner, L. Zhang and W.E. Mustain, J. Mat. Chem. A, 2(6) (2014) 1627-1630.