Cathode materials have been the bottleneck to improve the performance and reduce the cost of lithium-ion batteries. Lithium iron phosphate is the first choice of cathode materials for modern commercial lithium-ion batteries because of its low price, high energy density, long life and good safety. However, the low electronic conductivity of lithium iron phosphate seriously hinders its application in the field of power and energy storage batteries.

At present, China's major cities are booming in the construction of rail transit projects. Because of its unparalleled advantages, shield method has been widely used in the construction of rail transit tunnels.

Tungsten disulfide (WS₂) is a kind of layered solid lubricant with structure similar to graphite. It has excellent high temperature resistance, extreme pressure resistance, good adsorption capacity on metal surface and low thermal conductivity. WS₂ was first applied to the lubrication of the key parts of the American mariner spacecraft, and it was used to prepare high temperature extreme pressure grease and energy-saving engine lubricating oil, with good application results.

Rare earth trivalent ions have rich 4f energy level configuration, and their fluorescence characteristics are greatly affected by the crystal field environment and the symmetry of the lattice. At present, many scholars use the small size effect of semiconductor nano materials (ZnO, TiO₂) and lattice sensitization to improve the optical properties of rare earth trivalent ions, which are widely used in biological fluorescent probes, optical devices and new luminescent materials.