Electrochemical behavior of a liquid tin electrode in molten ternary salt electrolyte containing sodium chloride, aluminum chloride, and tin chloride

One of the key limitations in the wide-scale adoption of mature renewable energy technologies is the lack of grid-level energy storage solutions. One important figure of merit in these battery systems is a high rate capability to match fluctuating demands for electricity. Molten salt batteries are an attractive option for stationary storage due to fast kinetics and good cycling capability, but high temperatures (>300 °C) limit available materials. In this thesis, the molten NaCl-AlCl3-SnCl2 electrolyte and liquid Sn electrode couple at 250 °C is investigated as part of the potential cell Na I NaCl-AlCl 3-SnCl2 I Sn for a lower temperature molten salt battery. An electrochemical study of the kinetics in the molten salt electrolyte and at the liquid Sn electrode-electrolyte interface is conducted using cyclic voltammetry and the galvanostatic pulse method. The liquid metal electrode is found to have suitably fast kinetics with an exchange current density of 92 mA/cm2. Parameters for a new Na+ conducting membrane are proposed, requiring an ionic conductivity of 0.056 S/cm, which would allow for a hypothetical Na I NaCl-AlC 3-SnCl2 I Sn battery to operate with an energy efficiency of 70%.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2016

Author dc:creator

• Watari, Raku

Advisor dc:contributor.advisor

• Donald R. Sadoway

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/104316

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/104316