Facile Stabilization of the Sodium Metal Anode with Additives: Unexpected Key Role of Sodium Polysulfide and Adverse Effect of Sodium Nitrate
Abstract
Sodium metal is an attractive anode for next‐generation energy storage systems owing to its high specific capacity, low cost, and high abundance. Nevertheless, uncontrolled Na dendrite growth caused by the formation of unstable solid electrolyte interphase (SEI) leads to poor cycling performance and severe safety concerns. Sodium polysulfide (Na2S6) alone is revealed to serve as a positive additive or pre‐passivation agent in ether electrolyte to improve the long‐term stability and reversibility of the Na anode, while Na2S6‐NaNO3 as co‐additive has an adverse effect, contrary to the prior findings in the lithium anode system. A superior cycling behavior of Na anode is first demonstrated at a current density up to 10 mA cm−2 and a capacity up to 5 mAh cm−2 over 100 cycles. As a proof of concept, a high‐capacity Na‐S battery was prepared by pre‐passivating the Na anode with Na2S6. This study gives insights into understanding the differences between Li and Na systems.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 25, 2018
- Source ID
- 10.1002/ange.201801818
Entities
People
- Chuanlong Wang
- Edward Matios
- Huan Wang
- Weiyang Li
Organizations
- Air Force Office of Scientific Research
- Dartmouth College