A stable room-temperature sodium–sulfur battery

Abstract

High-energy rechargeable batteries based on earth-abundant materials are important for mobile and stationary storage technologies. Rechargeable sodium–sulfur batteries able to operate stably at room temperature are among the most sought-after platforms because such cells take advantage of a two-electron-redox process to achieve high storage capacity from inexpensive electrode materials. Here we report a room-temperature sodium–sulfur battery that uses a microporous carbon–sulfur composite cathode, and a liquid carbonate electrolyte containing the ionic liquid 1-methyl-3-propylimidazolium-chlorate tethered to SiO2 nanoparticles. We show that these cells can cycle stably at a rate of 0.5 C (1 C=1675, mAh g−1) with 600 mAh g−1 reversible capacity and nearly 100% Coulombic efficiency. By means of spectroscopic and electrochemical analysis, we find that the particles form a sodium-ion conductive film on the anode, which stabilizes deposition of sodium. We also find that sulfur remains interred in the carbon pores and undergo solid-state electrochemical reactions with sodium ions.

Reliable seawater battery anode: controlled sodium nucleationviadeactivation of the current collector surface

“…[12][13][14][15][16] Although the specific energy capacity of Na (1,166 mAh/g) is lower than that of Li metal-based battery (3,861 mAh/g), the costeffectiveness of Na metal precedes the high capacity of Li in the next-generation battery industry since it could be acquired directly even from the ubiquitous aqueous NaCl solution.…”

Designing solid-liquid interphases for sodium batteries

“…Although sodium-based batteries pre-date those based on lithium 3 , Li has received more recent attention for a variety of reasons, including its greater electronegativity, higher specific energy, low atomic radius 4, 5 , and the commercial success of related Li-ion battery technology. The greater natural abundance of sodium and its availability in regions all over the world provide significant cost advantages over Li that have within the last decade helped re-ignite interest in Na-based batteries 6–8 . Metallic sodium has other attractive features as a battery anode, including its relatively high electronegativity and low atomic weight, which combine to give the Na anode a specific capacity (1166 mAh gm −1 ) that is competitive with Li (3860 mAh gm −1 ) in many applications 6 .…”

“…The greater natural abundance of sodium and its availability in regions all over the world provide significant cost advantages over Li that have within the last decade helped re-ignite interest in Na-based batteries 6–8 . Metallic sodium has other attractive features as a battery anode, including its relatively high electronegativity and low atomic weight, which combine to give the Na anode a specific capacity (1166 mAh gm −1 ) that is competitive with Li (3860 mAh gm −1 ) in many applications 6 . Additionally, recent studies have shown that rechargeable batteries that pair a Na anode with highly energetic O 2 -based cathodes are intrinsically more stable during discharge than their Li analogs because the species generated electrochemically in the cathode, the metal superoxide, is more stable when the anode is Na, as opposed to Li 9, 10 .…”

“…Unlike Li, where dendrite-induced short circuits are considered the dominant failure mode, chemical reaction between the electrolyte and metal anode are regarded as the most important mechanism of cell failure for batteries based on a Na anode. Na also has a lower melting point than Li, which makes batteries based on Na more prone than their Li counterparts to failure by thermal runaway and/or dendrite breakage 6, 18, 19 .…”

Fluorine-free electrolytes for all-solid sodium-ion batteries based on percyano-substituted organic salts

“…Nonetheless, continued interest in such technologies stems from their processing ability and flexibility, higher safety due to the absence of flammable organic solvents and high dimensional stability45678910111213. Despite not being fluid in a wide temperature range, polyethers were first shown to dissolve inorganic salts and conduct resulting ions at room temperature in the 1970s14.…”