Principle of Na-ion batteries

Sara PaksereshtSakarya University

Definition

• Sodium-ion batteries are a type of rechargeable battery that uses sodium ions as charge carriers.

• Sodium-ion battery is relatively young compared to other battery types.

• The battery-grade salts of sodium are cheap and abundant, much more than those of lithium.

• The first successful attempt of a sodium battery was undertaken in 1967 by Ford Motor Company (USA) in the sodium-sulfur battery.

• These factors: price, abundance and size, make sodium-ion batteries particularly interesting for large scale grid storage applications.

-Designed by Williams Advanced Engineering ,UK, the sodium-ion battery is dramatically cheaper and safer than traditional lithium-ion batteries.

• Sodium-ion batteries have shown great promise for large-scale storage of renewable energy.

Phones could soon be powered by SALT:

• Sodium-ion batteries are cheaper and last longer than cells currently used in gadgets

• Prototype made with sodium had more charge cycles than Lithium-ion

• It also charged faster and delivered energy more quickly• Raw material is 1,000 times more common than lithium, and safer.

Energy storage• The sodium ion battery stores energy in chemical bonds of

its anode.

• When the battery is charging Na+ ions de-intercalate and migrate towards the anode. Meanwhile charge balancing electrons pass from the cathode through the external circuit containing the charger and into the anode.

• During discharge the process reverses. Once a circuit is completed electrons pass back from the anode to the cathode and the Na+ ions travel back to the cathode.

• Sodium ion cells have been reported with a voltage of 3.6 volts, able to maintain 115 Ah/kg after 50 cycles.

Structure of Na ion battery• They are many kinds of cathode materials for Na ion cells that

have been examined, such as chalcogenides, fluorides, polyanion compounds and oxide compound.also chromium cathodes have been tested as cathodes.

• Sodium fluorophosphates is tested for new cathode materials.

• Different electrolyte are used for Na ion batteries such as: ethylene carbonate (EC),diethyl carbonate (DEC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), butylene carbonate (BC), and vinylene carbonate (VC) and salt combinations: LiPF6, and NaClO4.

• Porous carbon has been identified as one for anode material. In porous carbon, Na ions can be reversibly inserted into nanopores or absorbed on the surface of carbon, providing capacity of less than 200 mA h g − 1. In addition to carbon anodes, alloying different types of anode with additives such as Antimony (Sb), Tin (Sn), Phosphorus (P), Germanium (Ge) and Lead (Pb) can also yield results. 

Advantages• rechargeable sodium-ion batteries for energy storage

• Easier to recycle

• Low market prices.

• Capable of working at room temperature, Good efficiency.

Disadvantages

● large ionic size of Na+ which require more power to keep energy flowing.

● It takes several days to charge in case you forget to charge it full

● lower operating voltage ●  lower energy density ● Need high temperature for optimal work

Review of literatures

Electrochemical properties of tin oxide anodes for sodium-ion batteries

• Few tin (Sn)-oxide based anode materials have been found to have large reversible capacity for both sodium (Na)-ion and lithium (Li)-ion batteries. Kyushu University report the synthesis and electrochemical properties of Sn oxide-based anodes for sodium-ion batteries: SnO, SnO2, and SnO/C. Among them, SnO is the most suitable anode for Na-ion batteries with less first cycle irreversibility, better cycle life, and lower charge transfer resistance.

• The energy storage mechanism of the above-mentioned Sn oxides was studied, which suggested that the conversion reaction of the Sn oxide anodes is reversible in Na-ion batteries. The better anode performance of SnO is attributed by the better conductivity.

SEM images: (a) Low magnification image of SnO; (b), (c) medium magnification images of flower-like SnO; (d) layer-shape grains of SnO.

TEM images: (a), (b), SnO2; (c), (d) TEM images of SnO2/C;

SnO2/super P nanocomposites as anode materials for Na-ion batteries with enhanced electrochemical performance

• SnO2 nanoparticles (~5 nm) anchored on super P carbon spheres have been successfully synthesized by a simple hydrothermal method. The electrochemical performances of bare SnO2, super P and SnO2/super P nanocomposite were investigated.

• The results show that SnO2/super P nanocomposite electrode displays much better cycling stability and rate capability than bare SnO2.It demonstrated a high discharge capacity of 293 mAh /g after 100 cycles. The enhanced electrochemical performances of composite is attributed to the ultrafine SnO2 nanoparticle (~5 nm) and the introduction of conductive super P.

• This leads to high Na ion diffusion coefficient and a good structural stability of SnO2/super P nanocomposite. Therefore, using super P is an effective way to improve the electrochemical performances of SnO2 electrode.

SEM image (a), TEM image (b), HRTEM image (c) and SAED pattern (d) of SnO2

Eldfellite, NaFe(SO4)2: an intercalation cathode host for low-cost Na-ion batteries

• Professor John Goodenough, the inventor of the lithium-ion battery, and his team have identified a new cathode material made of the nontoxic and inexpensive mineral eldfellite, presenting a significant advancement in the race to develop a commercially viable sodium-ion battery.

• The mineral eldfellite, NaFe(SO4)2, is characterized as a potential cathode for a Na-ion battery that is fabricated in charged state; its 3V discharge versus sodium for reversible Na+

intercalation is shown to have a better capacity, but lower insertion rate than Li+ intercalation. The theoretical specific capacity for Na+ insertion is 99 mA h g−1. After 80 cycles at 0.1C rate versus a Na anode, the specific capacity was 78 mA h g−1 with a coulomb efficiency approaching 100%.

Crystal structure of eldfellite, NaFe(SO4)2 (a) planner view

SEM images of as prepared NaFe(SO4)2

References

1. 1D to 2D Na+ Ion Diffusion Inherently Linked to Structural Transitions in Na0.7CoO2 .M. Medarde, M. Mena, J. L. Gavilano, E. Pomjakushina, J. Sugiyama, K. Kamazawa, V. Yu. Pomjakushin, D. Sheptyakov, B. Batlogg, H. R. Ott, M. Månsson, and F. Juranyi .Phys. Rev. Lett. 110, 266401 (2013).

2. J. Xu, D. H. Lee, Y. S. Meng, “Recent advances in sodium intercalation positive electrode materials for sodium ion batteries“, Functional Material Letters, 2013.

3. D. H. Lee, J. Xu, Y. S. Meng, “An advanced cathode for Na-ion batteries with high rate and excellent structural stability“, Phys. Chem. Chem. Phys., 2013.

4. Veronica Palomares et al., Na-ion batteries, recent advances and present challenges to become low cost energy storage systems. In: Energy and Environmental Science 5, (2012).

5. Huilin Pan et al, Room-temperature stationary sodium-ion batteries for large-scale electric energy storage. In: Energy and Environmental Science 6, (2013).

6. http://hightechindustryinjapan.blogspot.com.tr/2013/09/no-784-successful-experiment-to-make.html