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Title: Next generation molten NaI batteries for grid scale energy storage

Robust, safe, and reliable grid-scale energy storage continues to be a priority for improved energy surety, expanded integration of renewable energy, and greater system agility required to meet modern dynamic and evolving electrical energy demands. We describe here a new sodium-based battery based on a molten sodium anode, a sodium iodide/aluminum chloride (NaI/AlCl 3) cathode, and a high conductivity NaSICON (Na 1+xZr 2Si xP 3–xO 12) ceramic separator. This NaI battery operates at intermediate temperatures (120–180 °C) and boasts an energy density of >150 Wh kg –1. The energy-dense NaI-AlCl 3 ionic liquid catholyte avoids lifetime-limiting plating and intercalation reactions, and the use of earth-abundant elements minimizes materials costs and eliminates economic uncertainties associated with lithium metal. Moreover, the inherent safety of this system under internal mechanical failure is characterized by negligible heat or gas production and benign reaction products (Al, NaCl). Scalability in design is exemplified through evolution from 0.85 to 10 Ah (28 Wh) form factors, displaying lifetime average Coulombic efficiencies of 99.45% and energy efficiencies of 81.96% over dynamic testing lasting >3000 h. Here, this demonstration promises a safe, cost-effective, and long-lifetime technology as an attractive candidate for grid scale storage.
ORCiD logo [1] ;  [2] ;  [1] ;  [2] ;  [2] ;  [2] ;  [1] ;  [1] ; ORCiD logo [2] ;  [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. Ceramatec Inc., Salt Lake City, UT (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0378-7753; 663094
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Power Sources
Additional Journal Information:
Journal Volume: 360; Journal Issue: C; Journal ID: ISSN 0378-7753
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE Office of Electricity Delivery and Energy Reliability (OE)
Country of Publication:
United States
25 ENERGY STORAGE; Sodium battery; NaSICON; Ion conductor; Grid scale; Energy storage
OSTI Identifier: