Sodium-ion batteries primarily use sodium salts as electrode materials, which are more abundant and cheaper than lithium salts. Because sodium ions are larger than lithium ions, sodium-ion batteries are a cost-effective alternative when weight and energy density requirements are not critical.
Sodium-sulfur (NaS) batteries are a new type of chemical power source, consisting of a positive electrode, a negative electrode, an electrolyte, a separator, and a casing. Unlike general secondary batteries (lead-acid batteries, nickel-cadmium batteries, etc.), sodium-sulfur batteries are composed of molten electrodes and solid electrolytes. The active material of the negative electrode is molten metallic sodium, and the active material of the positive electrode is liquid sulfur and sodium polysulfide molten salt.
So, what are the differences between sodium-ion batteries and sodium-sulfur batteries? Details are as follows:
1. Different production costs
The active material of the negative electrode of sodium-sulfur batteries is molten metallic sodium, and the active material of the positive electrode is liquid sulfur and sodium polysulfide molten salt. These materials need to be produced through complex processes. In contrast, the electrode material of sodium-ion batteries is mainly sodium salt, which is widely found in nature and is cheaper and has a lower production cost.
2. Different operating temperatures
Sodium-ion batteries primarily rely on the movement of sodium ions between the positive and negative electrodes to achieve charging and discharging, similar to lithium-ion batteries. Their operating temperature range is generally -40 to 80°C. In contrast, the electrolyte materials used in sodium-sulfur batteries only exhibit good conductivity at temperatures above 300°C; therefore, the normal operating temperature for sodium-sulfur batteries is 300-350°C.
3. Different application areas
Sodium-ion batteries are still in the experimental stage and a mature upstream and downstream industrial chain has not yet been established. In addition, their energy density is basically the same as that of lithium iron phosphate batteries. Therefore, experts predict that the future application areas of sodium-ion batteries will be as power sources for consumer electronics products, as well as for low-speed electric vehicles, electric bicycles and other fields.
Sodium-sulfur batteries have the advantages of high energy, long life and high efficiency, but they are also limited by their extremely high operating temperature. Therefore, sodium-sulfur batteries are currently mainly used in the field of energy storage, such as solar power plants, wind power plants and hydropower plants.
