The lithium-killer? Sodium-ion batteries: In the last decade, lithium-ion batteries have dominated, powering everything from phones to EVs, and are seen as the king of all energy storage. However, its throne seems to be getting shaken. Sodium-ion batteries (SIBs) are on their way not just to compete with, but to blow away, the lithium monopoly.
The obvious advantage of lithium-ion batteries-the fact that they require the lithium-is a major drawback, as lithium is finite, relatively costly, and has problematic geographics. Because it only exists in abundance in three major countries (Australia, China and Chile), extracting it is costly and damaging. Prices have also fluctuated because of the increased demand from the ever growing EV market. On the other hand, sodium is plentiful- the sixth most abundant material on Earth in the form of oceanic salt, or common table salt. This is also cheap to extract and ethical.
Why didn’t sodium conquer the market years ago then? For a long time, the reasoning was due to physics- because sodium atoms are larger and heavier than those of lithium it becomes harder to insert them into electrode surfaces without damaging the integrity of the surface or losing efficiency. However, recent advancements have now revolutionized the concept, using hard carbon anodes and layer oxides that can accommodate sodium ions much more effectively without damage and increase the energy density up to 160Wh/kg. Though not yet as high as lithium’s 250-300 Wh/kg, it’s sufficient for home storage systems, EVs with lower demands, and backup power for renewable energy sources. Furthermore, for non weight sensitive equipment, such as home batteries or forklifts, they have already surpassed lithium.
What seems to be the killer advantage of SIBs though? The cost. SIBs are at least 30-50% cheaper than Li-ion batteries due to the substitution of aluminium (rather than copper) for current collectors, the removal of expensive nickel, cobalt and, of course, lithium. It removes costly and unreliable supply chain problems, and avoids ethically problematic mineral extraction.
Additionally, they score extremely well on safety and lifespan. They can tolerate deep discharging and operate below freezing point- unlike Li-ion batteries which tend to catch fire easily at extreme conditions. They can also undergo thousands of recharges and discharges – potentially outliving the batteries that lithium uses five times over.
While Li-ion batteries won’t be disappearing anytime soon due to their energy density for high-performance EVs, SIBs will eventually dominate the market for lower-energy products such as two-wheelers, mini-EVs, residential energy storage and the grid- moving the market from an “if only we had enough lithium?” mentality to a “if only we could collect enough sea salt?” one- a significant transition and the dawn of the lithium killer.
