Sodium-based batteries are batteries that combine sodium with a compound called inositol. They were developed in October 2017 by researchers at Stanford University. This new type of battery uses sodium combined with inositol, an organic compound commonly found in household products, including infant formula. Just as sodium is much more abundant than lithium, rice bran alcohol is easily extracted from rice bran and can also be found as a byproduct of corn processing.
Main principle of sodium-based batteries
In sodium-ion batteries, sodium ions can attach to inositol, a common compound extracted from liquid byproducts of rice bran or corn processing. This novel combination of sodium ions and inositol significantly improves the ion cycle in sodium-based batteries, allowing ions to move more efficiently from the cathode through the electrolyte to the phosphorus anode, resulting in a stronger current.
One of the biggest obstacles facing sodium- and potassium-based batteries is their faster decay and degradation, and their lower energy density compared to lithium-ion batteries. However, this isn't always the case. Researchers studying the reactions of lithium, sodium, and potassium ions with iron sulfide particles found that sodium and potassium are more stable with iron sulfide during the reaction, suggesting that sodium- or potassium-based batteries may have a much longer lifespan than expected.
The difference between sodium-based batteries and lithium-ion batteries
1. The difference lies in the internal charge carriers of the batteries. Lithium-ion batteries achieve charging and discharging by the movement and conversion of lithium ions between the positive and negative electrodes, while sodium-ion batteries achieve charge transfer by the insertion and extraction of sodium ions between the positive and negative electrodes. In fact, the working principles of the two are the same.
2. The two have different ionic radii, and this difference in radius results in the performance of sodium-ion batteries being far inferior to that of lithium-ion batteries. The negative electrode of lithium-ion batteries can be graphite, but sodium ions can hardly be inserted/extracted into graphite, resulting in a very small capacity. Other carbon materials can reach a maximum capacity of about 300 mAh after processing. The capacity of sodium ions in the positive electrode is very small, only about 100 mAh. The insertion/extraction resistance of sodium ions in the positive and negative electrodes is very large due to their large radius. The reversibility is poor, and the irreversible capacity loss is large.
Currently, the core technology of new energy vehicles lies in lithium-ion batteries. However, a sodium-based battery has emerged that can store the same amount of energy as the latest lithium-ion batteries at a lower cost. Material costs account for a quarter of the battery price. Lithium-ion batteries have been around for 25 years and have consistently held a significant market share, but lithium is becoming increasingly scarce and its mining costs are rising. Therefore, scientists have discovered that sodium can also store ions, and that it offers lower manufacturing costs and higher energy capacity.
While the new sodium-based battery may never meet the needs of electric vehicle manufacturers, researchers believe it will help store energy obtained from sustainable energy sources such as solar panels and wind turbines.
