Sodium Ion

Analogous to the lithium-ion battery but using sodium ions (Na+) as the charge carriers. The working of the sodium based chemistry and cell construction are almost identical with those of the commercially widespread lithium-ion battery types, but sodium compounds are used instead of lithium compounds.

sodium ion

Sodium Ion Cell

  • 100 to 150 Wh/kg and 290Wh/litre at cell level
  • 1000 W/kg and 1300 W/litre at cell level
  • Voltage range 1.5 to 4.3V
    • cells can be discharged down to 0V and shipped at 0V
  • 20-30% lower cell BOM cost than LFP
  • Temperature range -20°C to +60°C
  • Typical cathode materials: NaNi0.68Mn0.22Co0.10O2
optimization of hard carbon for sodium ion - poster

Hard Carbon Anodes in Sodium-ion

  • Emerging battery technology – promising cost, safety, sustainability, and performance advantages over current commercialised lithium-ion batteries1,2.
  • Advantages:
    • widely available
    • inexpensive raw materials
    • rapidly scalable technology
    • meeting global demand for carbon-neutral energy storage solutions3,4.
  • Adding metals would increase the overall energy density, but results in volumetric changes leading to failure.

Sodium-Ion Degradation

  • Over-voltage Charging
  • Presence of Hydrogen
    • causes irreversible degradation of α-NaMnO2 when used as the cathode in Na-ion batteries [1].
  • Defects in the Cathode Atomic Structure
    • these form during the steps involved in synthesizing the cathode material. These defects eventually lead to a structural earthquake in the cathode, resulting in catastrophic performance decline during battery cycling [2].

References

  1. Zhen Zhu, Hartwin Peelaers, Chris G. Van de Walle, Supporting Information: Hydrogen-induced degradation of NaMnO2, Chem. Mater. 2019, 31, 14, 5224–5228, June 21, 2019
  2. Xu, GL., Liu, X., Zhou, X. et al. Native lattice strain induced structural earthquake in sodium layered oxide cathodes. Nat Commun 13, 436 doi: 10.1038/s41467-022-28052-x
  3. Behrooz Mosallanejad et al, Cycling degradation and safety issues in sodium-ion batteries: Promises of electrolyte additives, Journal of Electroanalytical Chemistry, Volume 895, 15 August 2021, 115505