Sodium-ion Technology

Over the last few years, interest in high energy density sodium ion (Na-ion) batteries has increased.

However, relatively little research has been conducted in this area and, as a result, these next generation materials have not yet been brought to market. Na-ion batteries are a direct replacement for lithium-ion (Li-ion) batteries, allowing current Li-ion battery manufacturers to use existing equipment to construct batteries using Faradion’s next-generation materials.

Benefits of Faradion sodium-ion technology

Faradion’s sodium-ion technology has already shown specific energy densities in full cells far exceeding those of other known sodium-ion materials. In addition, the Faradion team have already developed materials with energy densities exceeding that of the popular Li-ion material lithium iron phosphate, dispelling the misconception held by some that sodium-ion materials will be unable to achieve high energy densities. The graph below shows a comparison of the cathode specific energy densities of some sodium ion materials achieved in full cells, with LiFePO4 included as a well-known comparison.

Energy Density Graph -Picture

Graph showing the specific energies (based on discharge 1) of sodium ion materials achieved in sodium ion cells
(a) NaVPO4F (~ 14 mA/g), J. Barker, M.Y. Saidi, J.L. Swoyer, Electrochem. Solid St., 2003 , 6 , A1.
(b) NaN1/3Fe1/3Mn1/3O2 (15 mA/g), D. Kim, E. Lee, M. Slater, W. Lu, S. Rood, C.S. Johnson, Electrochem. Commun., 2012. 18, 66.
(c) NaNi0.5Mn0.5O2 (25 mA/g), S. Komaba, W. Murata1, T. Ishikawa, N. Yabuuchi, T. Ozeki, T. Nakayama, A. Ogata, K. Gotoh, K. Fujiwara, Adv. Funct. Mater., 2011, 21, 3859.
(d) Na0.67Ni1/3Mn2/3O2 (10 mA/g), Data collected at Faradion
(e) LiFePO4 (~ 10 mA/g), Data collected at Faradion

 

Sodium-ion (Na-ion) technology is similar to lithium-ion (Li-ion) technology and the following points highlight the important similarities and differences:

Availability and Cost

  • Na-ion materials have lower material costs than Li-ion materials (e.g. sodium carbonate is < 10 % of the cost of the equivalent lithium salt). Furthermore, cathode and electrolyte costs can be ~ 50 % of cell costs, so the overall cost reduction is substantial
  • Na is far more abundant in the earth’s crust than Li (Na ~ 2.6 % vs. Li ~ 0.005 %) making this technology more sustainable
  • Drop-in solution
    • Na-ion materials can be processed in the same way as Li-ion materials at every step, from the synthesis of the active materials to the electrode processing. This will allow current Li-ion battery manufacturers to use existing equipment to construct batteries using Faradion’s novel materials.
    • Existing Li-ion manufacturing lines can be used to make Na-ion batteries

Current collectors in sodium-ion cells can be fabricated from aluminium rather than the more expensive copper necessary in lithium cells

Energy density

Faradion’s novel Na-ion cells have energy densities similar to those of conventional Li-ion materials

Power

Initial electrochemical tests have shown that the rate capabilities of Faradion’s Na-ion materials can be as good as those of conventional Li-ion materials

Safety

Safer materials (improved thermal stability) and improved transport safety

Cycle life

Preliminary cell testing has shown excellent cycle life in many of Faradion’s novel materials

Shelf life

Preliminary analysis indicates similar shelf life to currently available Li-ion materials

Faradion’s sodium-ion technology

Faradion’s novel technology is already being employed within 3 Ah prismatic cells, which are currently being supplied to Williams Advanced Engineering as part of a project co-funded by Innovate UK, the UK’s innovation agency. The cells are being incorporated into battery packs by Williams, as shown in the design below.

 

WAE 48-cell pack design

A 48 cell battery pack design by Williams Advanced Engineering, incorporating Faradion’s 3 Ah cells.

 

Intellectual property

Compared to Li-ion technology, relatively little research has been conducted on Na-ion materials. Faradion has now filed more than 10 patent families covering applications, materials and material synthesis.

Availability for licensing

Parties interested in further discussions about using the Faradion technology, please contact us.