272693 In Situ Spatio-Temporal Measurements in Aqueous Hybrid Battery Electrodes

Wednesday, October 31, 2012: 3:32 PM
Cambria East (Westin )
Katherine Hess1, Jay Whitacre2,3 and Shawn E. Litster1, (1)Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, (2)Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, (3)Engineering and Public Policy, Carnegie Mellon University

Aqueous sodium hybrid batteries are a promising grid-scale energy storage technology for expanding intermittent renewable energy resources such as wind and solar. These batteries use sodium intercalation cathodes, electric double layer capacitance anodes and leverage the high mobility in aqueous electrolytes to enable cells with ultra-thick electrodes. The use of ultra-thick electrodes means that electrodes with large energy storage capability can be made with smaller surface areas thereby reducing the costs of non-functional materials (e.g., separators). However, increases of thickness result in reduced power density and increased charging times. New electrode designs are needed to further increase thicknesses while maintaining desired power density and it is valuable to have spatially resolved data across the electrode thickness to aide in the design and characterization process. This work presents a novel electric scaffold for measuring in-situ voltage, local current, charging current, and charge stored distributions across electrodes in the electric and electrolyte phases. The electrode scaffold uses alternating insulating and sensing layers, which surround a column of electrode. Potential measurements are simultaneously gathered from each sensing layer, giving spatio-temporal distributions. Finite difference methods are then applied to the data to obtain the local current and charging current distributions.

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