Hollow sphere is a kind of material with special structure from nanometer to micrometer in size. Because of its low density, large specific surface area, good stability and surface permeability, these materials have important applications in chemistry, biology and materials science.

The composites composed of refractory metals and carbides are high temperature materials with excellent comprehensive properties. They make use of the complementary properties of materials to achieve comprehensive optimization. Tungsten-based refractory carbide composites are one of them. This kind of material has good thermal, chemical and mechanical compatibility, ideal high temperature strength and toughness, thermal shock resistance, ablation resistance and other excellent characteristics.

Tungsten disulfide is a gray-black hexagonal lattice-like material similar to graphite. Each layer is composed of two layers of sulfur atoms and one layer of tungsten atoms connected by the number of 2:1. Among them, sulfur and tungsten atoms are connected by strong covalent bonds. Sulfur atoms between layers are connected by van der Waals forces. The special crystal structure also makes tungsten disulfide more excellent than molybdenum disulfide lubricating oil additive of the same kind. Tungsten disulfide performs better in extreme pressure, wear and friction reduction, heat and oxidation resistance, etc.

Proton exchange membrane fuel cell (PEMFC) is considered as one of the most promising clean energy sources because of its high energy efficiency and non-pollution. PEMFC directly converts the chemical energy of fuel and oxidant (O2) into electric energy, which is a new type of power generation device.