Sodium-ion batteries - Science

Notes

• Uses sodium ions as charge carriers
• Replaces lithium with sodium as the cathode material
• Interest in the 2010s and 2020s
  • Lithium-ion
    • uneven geographic distribution
    • high environmental impact
    • high material cost
  • requires
    • **lithium
    • cobalt
    • copper
    • nickel
• -20C to 60C

Operating principle

• Cathode
• Anode (not necessarily sodium-based)
  • Hard carbon
    • Disordered carbon with non-graphitizable, non-crystalline, amorphous carbon
    • ~300 mAh/g
    • First demonstrated in 2003
      • 3.7V average volt
    • Preferred for
      • capacity
      • (lower) working potentials
      • cycling stability
  • Graphite
    • 300-360 mAh/g
    • 90-180 mAh/g
    • Demonstrated in 2015
    • Only a few hundred cycles
• Liquid electrolyte
  • Dissociated sodium salts
  • Polar protic or aprotic solvets
• Charging moves sodium ions cathode -> anode
  • Discharge reverses

Commercial presence

• No commercial electric vehicles using sodium-ion
• CATL mass producing SIBs since 2022
  • CATL is world's biggest battery manufacturer

Benefits of Sodium-ion

• Natural abundance of sodium
  • Easily harvested from saltwater
• Compared to lithium
  • Cheaper
  • Safer
  • Similar power delivery

Negatives of Sodium-ion

• Lower energy density than lithium-ion
• Insufficient charge-discharge cycles

References

1. [[Sodium-ion Batteries]]
2. Sodium-ion Batteries — ML