Which is better Sodium ion (NIB) or Lithium Ion ?
Recently, the term “Sodium ion (NIB) battery” (Sodium-ion battery) has resurfaced in our consciousness, igniting a fresh wave of interest in the battery sector.
What is a sodium-ion battery?
In fact, research on sodium-ion batteries had already begun in the 1980s. Electrode materials such as MoS2, TiS2, and NaxMO2, which were invented and developed in the early days, have poor electrochemical performance and progress is slow.
A sodium-ion battery is a type of secondary battery (rechargeable battery) that works primarily by transporting sodium ions between the positive and negative electrodes, similar to how lithium-ion batteries work.
In the periodic table of the elements, sodium and lithium are the closest metal elements of the same group, and their chemical properties are very similar. The number of electrons used in the outermost layer of the battery is exactly the same. The carrying capacity of lithium-ion batteries and sodium-ion batteries in charge and discharge reactions are also consistent.
Advantages of sodium batteries
The sodium salt, which is more available and less expensive than lithium, is utilised as the electrode material in sodium-ion batteries. Because sodium ions are bigger than lithium ions, sodium-ion batteries are a more cost-effective option when weight and energy density aren’t as important. Sodium-ion batteries have the following advantages over lithium-ion batteries:
- The supply of sodium salt raw materials is plentiful, and the price is low. The iron-manganese-nickel-based cathode material is utilised instead of the ternary cathode material in lithium-ion batteries, and the raw material cost is cut in half.
- Because of the properties of sodium salt, it is possible to utilise a low-concentration electrolyte (the conductivity of sodium salt is about 20% higher than that of lithium electrolyte at the same concentration of electrolyte) to save money.
- Because sodium-ions do not form an alloy with aluminium, aluminium foil can be utilised as the negative electrode’s current collector, lowering the cost by around 8% and reducing the weight by about 10%.
- Since the sodium-ion battery has no over-discharge characteristics, the sodium-ion battery is allowed to discharge to zero volts. The energy density of sodium-ion batteries is greater than 100Wh/kg, which is comparable to lithium iron phosphate batteries, but its cost advantage is obvious, and it is expected to replace traditional lead-acid batteries in large-scale energy storage.
The battery is now one of the most expensive components of modern energy vehicles. The cost of sodium-ion batteries is one of their many advantages. It is certain that it will cut the overall cost of new energy vehicles in the future, but it also has significant disadvantages: low density of energy
Based on Energy Density
In terms of volume and mass, the volume of sodium ions is more than three times that of lithium-ions at the same weight, implying that the diameter of sodium-ions is bigger and the energy density is substantially lower than that of lithium batteries.
From the data we have seen on the Internet, the energy density of current sodium-ion batteries is about 80~100Wh/kg. In 2017, a 150Wh/kg sodium-ion battery was developed. Recently, various space compression schemes have been used, and the hybrid design of series and parallel integration of sodium and lithium batteries for new energy vehicle schemes has successfully rescued the energy density of the battery to about 160Wh/kg. To be honest, it can be compared with phosphoric acid. Lithium iron phosphate battery (LiFePO4) is comparable and is expected to replace the lead-acid battery market in the field of energy storage.
Nevertheless, lithium-ion batteries can have a higher energy density than sodium-ion batteries and are smaller and lighter. This is where sodium batteries are inherently inferior to lithium batteries.
Conclusion
In contrast to these advantages and disadvantages, sodium batteries do have a huge market, and with the popularity of new energy vehicles and energy storage industries, they are expected to replace the traditional lead-acid battery market. The prices of cobalt, nickel, and lithium carbonate are constantly increasing. Under the rising market conditions, sodium salt can be said to be a big advantage. But we cannot reject the characteristics and advantages of lithium batteries. At least in the next 30 to 50 years, lithium batteries may still be one of the mainstream batteries in drones, smart wearables, medical and industrial industries.
