In today’s digitised world, battery technology is undoubtedly a key component that underpins our daily lives, from smartphones to electric cars to off-grid home power. However, whilst lithium-ion batteries have been hugely successful in the marketplace, their high cost, environmental impact and potential geopolitical risks have created a strong interest in finding new alternatives.
Recently, the technology of sodium-ion batteries (NIB) has attracted a lot of attention. This new battery technology is expected to be a significant alternative to lithium-ion batteries due to its low cost, safety and durability. The development of sodium-ion batteries has already caused a technological revolution worldwide and is expected to have a profound impact on the entire power storage industry in the coming years.
The core principle of the sodium-ion battery is not really complicated. It is similar in design to a lithium-ion battery, except that sodium is used instead of lithium. In the anode portion of the battery, sodium atoms are ionised into positively charged sodium ions, which then travel through the electrolyte to the cathode portion, where they combine with electrons to form negatively charged sodium ions. This process is the charging and discharging process of the battery.
However, sodium is much more abundant and inexpensive than lithium. According to statistics, the current price of sodium carbonate is only US$286 per tonne, which is much lower than that of battery-grade lithium carbonate at US$20,494 per tonne. This means that if sodium-ion batteries are produced and promoted on a large scale, the cost of storing electricity will be greatly reduced.
Sodium-ion battery vs. lithium-ion battery cost comparison.
In addition, sodium-ion batteries have some unique advantages. For example, they can work in a wider range of temperatures, from -30°C to 60°C and even 80°C; they are also safer and less prone to thermal runaway phenomenon; and they have a longer cycle life, and can still maintain a higher capacity even after multiple charging and discharging.
In recent years, research institutes and companies around the world have invested in the research and development of sodium-ion batteries. For example, a research team at Tokyo University of Science has developed a new generation of sodium-ion batteries using nanostructured hard carbon as the cathode, with an energy density of 312 watt-hours per kilogram, which is roughly double that of lithium iron phosphate (LFP) batteries. This is certainly exciting news, as LFP batteries are now widely used in electric vehicles.
