Scientists have developed a process that significantly increases the capacity of sodium-ion batteries.


This article makes the following points:
  • Sodium is the sixth most abundant metal globally, making it a much cheaper alternative to lithium.
  • But a sodium-ion battery's performance is poor compared to lithium-ion batteries.
  • Part of the reason is due to sodium ions being bigger than lithium ions. 
  • When cycling a battery (intercalation), ions freely move in and out of the graphite electrode. 
  • However, bulkier sodium ions can't be stored efficiently, reducing the sodium-ion battery's performance to about a tenth of a lithium-ion battery.
  • Swedish Scientists have turned to a Janus graphene featuring molecules on only one side that act as both spacers and active interaction sites for sodium ions.
  • The molecules facilitate electrostatic interactions between the stacked sheets and create more space between them, resulting in a tenfold increase in capacity.
  • Professor Aleksandar Matic stated, "It was really exciting when we observed the sodium-ion intercalation with such high capacity."