Some studies on sodium/sulfur cells

Bauer, Reinhold; Haar, W.; Kleinschmager, H.; Weddigen, G.; Fischer, W.

doi:10.1016/0378-7753(76)80015-8

Cited by 18 publications

(2 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This proposed corrosion reaction is in a good agreement with the results published in the literature, where the electrode potential of an oxygen electrode (O 2− /O 2 ) was more negative compared to the potential of S x 2− /S 2− in molten salts. Iron compounds, such as FeS (observed in sulfidation of iron in sulfur vapor) or FeSO 4 , generated from the proposed corrosion reactions generally have higher solubility in molten salts compared to oxide layers (Fe 2 O 3 ) that exist as passivation layers in melts . Exposing pure Fe metallic surfaces by forming more soluble iron compounds through the reaction between iron oxide and polysulfide species is critical for obtaining full capacity in a Na–FeCl 2 battery assembled in the discharged state.…”

Section: Resultsmentioning

confidence: 99%

An Advanced Na–FeCl₂ ZEBRA Battery for Stationary Energy Storage Application

Kim

et al. 2015

Advanced Energy Materials

View full text Add to dashboard Cite

development efforts are still required for reducing the cost and improving the cycle life needed before further penetration of ZEBRA batteries into the stationary energy-storage market.The important effort would be adopting a low-cost cathode chemistry that would replace the Ni cathode with low-cost cathode materials. Among various cathode chemistries that have been considered, [12][13][14][15] the Na-FeCl 2 redox couple could be a promising candidate for a lowcost ZEBRA battery. The overall reaction of Na-FeCl 2 redox couple and battery schematics are described in Figure 1 . [ 16,17 ] The theoretical specifi c capacity and energy density of the Na-FeCl 2 redox reaction are 310 mAh g −1 and 729 Wh kg −1 (without considering melts), which are quite comparable to the values from the Na-NiCl 2 redox couple. Na-FeCl 2 battery technologies have potential advantages over the current state-of-the-art Na-NiCl 2 ZEBRA battery technologies: (1) lower cathode material cost, where the price of Fe (LME price $0.48 kg −1 ) is much lower than Ni (LME price $14.5 kg −1 ) [ 18 ] and (2) more economical material choices (stainless steels could be used for cell components including cathode current collectors and cell cases). Based on the cost model of Na-NiCl 2 ZEBRA battery reported before, [ 19 ] it can easily be estimated that replacing Ni with Fe in Na-NiCl 2 battery could result up to 61% reduction in cell materials cost ($38 kWh −1 for Na-FeCl 2 ) shown in Figures S1 and S2 (Supporting Information). The real cost reduction from replacing Ni powder with Fe powders may not be as signifi cant as the LME price (additional costs for processes to obtain certain purity and particle size of metal powders); however, the advantages of utilizing earth abundance and low-cost Fe cathode in ZEBRA batteries are not diffi cult to foresee. Another effort is to operate a ZEBRA battery at an intermediate temperature (<200 °C), which could substantially lower capital, manufacturing, and maintenance costs by implementing a cost-effective, high-throughput manufacturing process such as compressive polymer seals rather than high-temperature batch processes such as glass sealing, thermal compression bonding, etc. Our recent studies on intermediate-temperature (IT) Na-NiCl 2 batteries reported that the lower operation temperature signifi cantly improves the cycle life by suppressing degradation mechanisms such as particle growth in the cathode materials of ZEBRA batteries. [ 20 ] Therefore, developing IT Na-FeCl 2 ZEBRA batteries is one of the most attractive approaches toward commercializing ZEBRA Sodium-metal chloride batteries, ZEBRA, are considered one of the most important electrochemical devices for stationary energy storage applications because of its advantages of good cycle life, safety, and reliability. However, sodium-nickel chloride (Na-NiCl 2 ) batteries, the most promising redox chemistry in ZEBRA batteries, still face great challenges for the practical application due to its inevitable feature of using Ni cathode (high materials cost). ...

show abstract

Section: Resultsmentioning

confidence: 99%

An Advanced Na–FeCl₂ ZEBRA Battery for Stationary Energy Storage Application

Kim

et al. 2015

Advanced Energy Materials

View full text Add to dashboard Cite

show abstract

“…[6] It has been reported that the addition of small concentrations of elemental selenium ( % 1 mol %) to the sulfur electrode of an NAS battery increases the reversibility of the redox processes. [52] Sulfur and selenium react on heating to very complex mixtures of cyclic and chain-like selenium sulfides Se x S y , but at low selenium concentrations the eightmembered ring molecule SeS 7 is the dominant seleniumcontaining species. [53] The one-electron reduction of SeS 7 may result in four different "opened-ring" radicals SeSC À 7 depending on the bond broken or nearly broken.…”

Section: Entrymentioning

confidence: 99%

Polysulfide Chemistry in Sodium–Sulfur Batteries and Related Systems— A Computational Study by G3X(MP2) and PCM Calculations

Steudel

2013

Chemistry A European J

View full text Add to dashboard Cite

The sodium-sulfur (NAS) battery is a candidate for energy storage and load leveling in power systems, by using the reversible reduction of elemental sulfur by sodium metal to give a liquid mixture of polysulfides (Na(2)S(n)) at approximately 320°C. We investigated a large number of reactions possibly occurring in such sodium polysulfide melts by using density functional calculations at the G3X(MP2)/B3LYP/6-31+G(2df,p) level of theory including polarizable continuum model (PCM) corrections for two polarizable phases, to obtain geometric and, for the first time, thermodynamic data for the liquid sodium-sulfur system. Novel reaction sequences for the electrochemical reduction of elemental sulfur are proposed on the basis of their Gibbs reaction energies. We suggest that the primary reduction product of S(8) is the radical anion S(8)(˙-), which decomposes at the operating temperature of NAS batteries exergonically to the radicals S(2)(˙-) and S(3)(˙-) together with the neutral species S(6) and S(5), respectively. In addition, S(8)(˙-) is predicted to disproportionate exergonically to S(8) and S(8)(2-) followed by the dissociation of the latter into two S(4)(˙-) radical ions. By recombination reactions of these radicals various polysulfide dianions can in principle be formed. However, polysulfide dianions larger than S(4)(2-) are thermally unstable at 320°C and smaller dianions as well as radical monoanions dominate in Na(2)S(n) (n=2-5) melts instead. The reverse reactions are predicted to take place when the NAS battery is charged. We show that ion pairs of the types NaS(2)˙, NaS(n)(-), and Na(2)S(n) can be expected at least for n=2 and 3 in NAS batteries, but are unlikely in aqueous sodium polysulfide except at high concentrations. The structures of such radicals and anions with up to nine sulfur atoms are reported, because they are predicted to play a key role in the electrochemical reduction process. A large number of isomerization, disproportionation, and sulfurization reactions of polysulfide mono- and dianions have been investigated in the gas phase and in a polarizable continuum, and numerous reaction enthalpies as well as Gibbs energies are reported.

show abstract

Elektrochemie neuer Speichersysteme

Beck

1988

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

Chemistry and material science predominate in the development of new storage batteries. Nevertheless, no perspective systematics is possible without the fundamental electrochemical aspects. The present review consequently tries to verify this feature and it generally avoids the descirption of individual systems. The industrial state of the art is characterized by energy densities of about 100 Wh/kg−1 and by satisfying cyclabilities.

show abstract

Some studies on sodium/sulfur cells

Cited by 18 publications

References 8 publications

An Advanced Na–FeCl₂ ZEBRA Battery for Stationary Energy Storage Application

An Advanced Na–FeCl₂ ZEBRA Battery for Stationary Energy Storage Application

Polysulfide Chemistry in Sodium–Sulfur Batteries and Related Systems— A Computational Study by G3X(MP2) and PCM Calculations

Elektrochemie neuer Speichersysteme

Contact Info

Product

Resources

About

Some studies on sodium/sulfur cells

Cited by 18 publications

References 8 publications

An Advanced Na–FeCl2 ZEBRA Battery for Stationary Energy Storage Application

An Advanced Na–FeCl2 ZEBRA Battery for Stationary Energy Storage Application

Polysulfide Chemistry in Sodium–Sulfur Batteries and Related Systems— A Computational Study by G3X(MP2) and PCM Calculations

Elektrochemie neuer Speichersysteme

Contact Info

Product

Resources

About

An Advanced Na–FeCl₂ ZEBRA Battery for Stationary Energy Storage Application

An Advanced Na–FeCl₂ ZEBRA Battery for Stationary Energy Storage Application