Quantification of ionic transport within thermally-activated batteries using electron probe micro-analysis

Journal Article · Sat Apr 30 00:00:00 EDT 2016 · Journal of Power Sources

DOI:https://doi.org/10.1016/j.jpowsour.2016.04.091· OSTI ID:1427179

Humplik, Thomas ^[1]; Stirrup, Emily K. ^[1]; Grillet, Anne M. ^[1]; Grant, Richard P. ^[1]; Allen, Ashley N. ^[1]; Wesolowski, Daniel E. ^[1]; Roberts, Christine C. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

The transient transport of electrolytes in thermally-activated batteries is studied in this paper using electron probe micro-analysis (EPMA), demonstrating the robust capability of EPMA as a useful tool for studying and quantifying mass transport within porous materials, particularly in difficult environments where classical flow measurements are challenging. By tracking the mobility of bromine and potassium ions from the electrolyte stored within the separator into the lithium silicon anode and iron disulfide cathode, we are able to quantify the transport mechanisms and physical properties of the electrodes including permeability and tortuosity. Due to the micron to submicron scale porous structure of the initially dry anode, a fast capillary pressure driven flow is observed into the anode from which we are able to set a lower bound on the permeability of 10^-1 mDarcy. The transport into the cathode is diffusion-limited because the cathode originally contained some electrolyte before activation. Finally, using a transient one-dimensional diffusion model, we estimate the tortuosity of the cathode electrode to be 2.8 ± 0.8.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1427179
• Alternate ID(s): OSTI ID: 1425695
• Report Number(s): SAND2015-8856J; 614045
• Journal Information: Journal of Power Sources, Vol. 320; ISSN 0378-7753
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
thermal battery
electron probe micro-analysis
electrolyte
mass transport
tortuosity
diffusion
permeability