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."