Is sodium ion battery better than lithium?

Sodium ion battery is a new type of battery. But the principle of sodium ion battery and lithium ion battery is similar , it is also a secondary battery. After hearing this, you may want to know is sodium ion battery better than lithium ion battery since sodium ion battery is newer.This article will tell you the answer.

The principle of sodium ion battery

In fact, sodium and lithium belong to the same main group of elements, and their charging and discharging behaviors are similar in operation. In the charging process, the sodium ions of the battery are released from the cathode and embedded in the anode. The more sodium ions embedded in the anode, the higher the charging capacity. When discharging, the reverse process occurs, the more sodium ions return to the anode, the higher the discharge capacity. The structure of sodium ion battery is similar to that of lithium ion battery, but due to the large radius of sodium ion, the regular layer structure of anode and cathode materials is preferred. The design of layer spacing is a key parameter affecting the performance of sodium ion battery.

Material for sodium ion battery

Similar to the structure of lithium ion battery, sodium ion battery is also composed of anode material, anode material, collector fluid, separator and electrolyte. The cathode materials mainly include transition metal oxides and Prussian compounds. Anode materials are mainly metal compounds, carbon – based materials, alloy materials. In addition to the anode and cathode materials, the collector plays an important role as the material carrying the anode and cathode activities and collecting electrons. Sodium ion battery work in a similar way to lithium ion battery, but the cation that flows through the electrolyte is sodium rather than lithium. Unlike lithium, sodium does not undergo electrochemical alloying with aluminum at room temperature, so copper aggregates can be replaced by cheaper aluminum. The separator can be the same separator of a lithium ion battery.

Development course and prospect of sodium ion battery

Development of sodium ion battery has continued in recent decades, especially for stationary energy storage applications. Due to the advantages of low cost, sodium ion battery has great development potential.

Early days: started in the 1970s, mainly for energy storage scenarios

Research on both sodium ion battery and lithium ion battery began in the 1970s. However, due to the higher requirements for research of sodium ion battery and people’s strong interest in lithium ion battery, the research on sodium ion battery developed slowly in the early stage. At this time, the research on sodium ion battery mainly focused on sodium-sulfur battery, which was first proposed by Ford Company in the United States. Because of its obvious advantages in low cost, it has been widely studied and applied in large-scale energy storage systems.

Medium term: environmental friendly and low cost, began to receive attention

Sodium ion battery has been noticed mainly because of: 1) the environmental pollution of lead-acid batteries cannot be ignored: although the solid and gaseous pollution of lead-acid batteries can be eliminated, the pollution of water-soluble lead heavy metal ions still cannot be avoided; 2) The global lithium resources are limited and unevenly distributed, so it cost high and will cause energy dependence; 3) cost advantage of sodium ion battery. At present, the price of raw materials for lithium ion batteries keeps rising. And sodium is easy to obtain, the cost advantage of sodium ion battery is obvious.

Current: Sodium ion battery has been gradually commercialized and applied

China’s research on sodium ion battery technology is now at the forefront of the world. Several companies have already made some achievements in sodium ion battery research. CATL recently released it’s first generation sodium ion battery, which has broken through some of the original disadvantages, it has high energy density and low temperature resistance. In recent years, with the increasing demand for energy storage, the demand for low-cost energy storage battery technology such as sodium ion battery is becoming increasingly urgent. Therefore, sodium ion battery may be widely used in the future.

High temperature sodium-sulfur battery and room temperature sodium-ion battery are the new sodium-based batteries which have developed rapidly in recent years and have a good application prospect in stationary energy storage power stations. Especially sodium ion battery, it has the similar work principle, structure, anode material system to lithium ion battery. Although the energy density of sodium ion battery is lower, , it has higher energy and power than lead acid battery, and the price is low. It shows a good development prospect in new energy storage and electric vehicle.

Advantages and disadvantages of sodium ion battery

Low energy density

Sodium ion battery has a similar energy density to nickel-metal hydride battery, but are not as high as lithium ion battery. The energy density of first generation of sodium ion battery independently developed by CATL we mentioned before, has made a great breakthrough and growth on the basis of the traditional sodium ion battery, as high as 160Wh/kg. It is a number of energy density that has been similar to the lithium iron phosphate battery. However, when compared with ternary lithium battery whit higher energy density, sodium ion battery is still not good enough.

Better performance of fast charge

The fast charging performance of sodium ion battery is better than that of lithium ion battery. The stokes diameter of sodium ion is smaller than that of lithium ion, and the electrolyte with the same concentration has higher ionic conductivity than lithium electrolyte, or the electrolyte with lower concentration can achieve the same ionic conductivity, and the fast filling performance is good. Although the radius of sodium ion is larger than that of lithium ion, it is difficult to embed into the crystal structure of the electrode, resulting in its slow movement rate, which needs to be improved by changing the characteristics of the anode material. Therefore, the research is more difficult than lithium ion battery, and has not been widely used in commercial use in recent years.

Safety performance is relatively stable

The electrochemical performance of sodium ion battery is relatively stable, it easy to passivate and deactivate in the process of thermal runaway, and the safety test performance is better than that of lithium ion battery. However, this is only discussed in terms of material properties. For lithium ion battery, which have been widely used in various electronic and electric equipment, the safety of lithium ion battery can be guaranteed as long as they are qualified battery products produced by regular manufacturers and used in the right way.

Application of sodium ion battery

At present, due to immature technology and incomplete industrial chain which need to be improved, sodium ion battery system has low production efficiency and poor product consistency, and its production cost is significantly higher than lithium ion battery, which to some extent offsets the material cost advantage. In addition, as we mentioned before, its energy density is lower than lithium ion battery, so it has not been widely used. With the gradual improvement of the industrial chain, as well as the improvement of technology and battery performance, the cost advantage of sodium ion battery will be gradually highlighted.

In conclusion, sodium ion battery has obvious cost advantage (after large-scale industrialization), and are comparable to lithium iron phosphate in cycle life and safety, as well as it not weaker than various types of lithium ion batteries in rate performance, high and low temperature performance.

Therefore, it is suitable for application scenarios with low energy density requirements, high cost sensitivity, or high cycle life requirements, such as light electric vehicles, new energy vehicles with medium and low endurance (less than 300km), standby power supply, base station power supply, electric energy storage, construction machinery, industrial vehicles, etc.

At present, sodium ion battery is still in the early stage of industrialization, and it is impossible to replace lithium ion battery for a long time in the future. They are more complementary and meet the application needs of different market segments.