Metal tungsten is a transition metal and belongs to the Group 6 elements of the 6th cycle. Because the radius of tungsten ions is small, the electricity price is high, and the polarization ability is strong, it is easy to form complex anions. Therefore, tungsten is mainly in the form of complex anions (WO4)2-, which combines with cations such as Fe2+, Mn2+, and Ca2+ in the solution to form wolframite or Precipitation of scheelite.
Metal tungsten is a silver-white metal with a hard and high density. Its density is 19.35 g/cubic centimeter, which is similar to gold. Its melting point is 3422°C and its boiling point is 5927°C. Tungsten has a slow evaporation rate and stable chemical properties. It is mainly used to manufacture filaments, high-speed cutting alloy steel, superhard molds, optical instruments, chemical instruments, etc.
In addition to the above uses, tungsten metal can also be used in the battery field. It is understood that nanometer yellow tungsten oxide, needle-shaped purple tungsten oxide, rod-shaped purple tungsten oxide, tungsten disulfide hollow spheres, tungsten disulfide nanosheets, tungsten diselenide nanosheets, nanotungstic acid, nanometer tungsten nitride, sodium tungstate , zinc tungstate and other tungsten compounds can be well used in sodium-ion batteries (sodium batteries) cathode materials, anode materials, electrolytes and separators.
The application of tungsten compounds in sodium-ion batteries is mainly reflected in the following aspects:
Tungsten compounds can be used as negative electrode materials for sodium batteries. Tungsten compounds have good electrochemical properties and stability and can effectively store and release sodium ions. By adjusting the structure or composition of the tungsten compound, its electrochemical performance can be further optimized and the energy density and cycle stability of the battery can be improved.
Tungsten compounds can be used as additives in sodium battery electrolytes. Tungsten compounds can improve the ionic conductivity and stability of the electrolyte, and improve the charge and discharge rate and rate performance of the battery. At the same time, tungsten compounds can also interact with other components in the electrolyte to form stable complexes, further optimizing battery performance.
Tungsten compounds can be used as one of the materials for sodium-ion battery separators. Tungsten compound has good mechanical strength and high temperature resistance, and can withstand the high temperature and high pressure environment during the operation of sodium batteries, ensuring the safety and stability of the battery. At the same time, tungsten compounds can also improve the ion conductivity and selectivity of the separator, further improving battery performance.
