A Molten Salt Lithium-Oxygen Battery
Abstract
Despite the promise of extremely high theoretical capacity (2Li + O_2 ↔ Li_2O_2, 1675 mAh per gram of oxygen), many challenges currently impede development of Li/O_2 battery technology. Finding suitable electrode and electrolyte materials remains the most elusive challenge to date. A radical new approach is to replace volatile, unstable and air-intolerant organic electrolytes common to prior research in the field with alkali metal nitrate molten salt electrolytes and operate the battery above the liquidus temperature (>80 °C). Here we demonstrate an intermediate temperature Li/O_2 battery using a lithium anode, a molten nitrate-based electrolyte (e.g., LiNO_3–KNO_3 eutectic) and a porous carbon O_2 cathode with high energy efficiency (∼95%) and improved rate capability because the discharge product, lithium peroxide, is stable and moderately soluble in the molten salt electrolyte. The results, supported by essential state-of-the-art electrochemical and analytical techniques such as in situ pressure and gas analyses, scanning electron microscopy, rotating disk electrode voltammetry, demonstrate that Li_2O_2 electrochemically forms and decomposes upon cycling with discharge/charge overpotentials as low as 50 mV. We show that the cycle life of such batteries is limited only by carbon reactivity and by the uncontrolled precipitation of Li_2O_2, which eventually becomes electrically disconnected from the O_2 electrode.
Additional Information
© 2016 American Chemical Society. Received: November 9, 2015; Published: February 12, 2016. This work is financially supported as part of the FY 2014 Vehicle Technologies Program Wide Funding Opportunity Announcement, under Award Number DE-FOA-0000991 (0991-1872), by the U.S. Department of Energy (DOE) and National Energy Technology Laboratory (NETL) on behalf of the Office of Energy Efficiency and Renewable Energy (EERE).Attached Files
Supplemental Material - ja5b11744_si_001.pdf
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Additional details
- Eprint ID
- 65111
- Resolver ID
- CaltechAUTHORS:20160307-103941099
- DE-FOA-0000991
- Department of Energy (DOE)
- National Energy Technology Laboratory (NETL)
- Created
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2016-03-08Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field