Nano-germanium has the advantages of narrow band gap, high absorption coefficient, and high mobility. When applied to the absorption layer of solar cells, it can effectively expand the absorption of the infrared band spectrum of solar cells.

Germanium has become the most promising negative electrode material for lithium-ion batteries due to its high theoretical capacity.

The theoretical mass capacity of germanium is 1600 mAh/g, and the volume capacity is as high as 8500 mAh/cm3. The diffusion rate of Li+ in Ge material is about 400 times that of Si, and the electronic conductivity is 104 times that of Si, so germanium is more suitable for high-current and high-power devices.

A study prepared a nano-germanium-tin/carbon composite material. The carbon material can improve the conductivity of germanium while adapting to its volume change. The addition of tin can further improve the conductivity of the material. In addition, the two components of germanium and tin have different potentials for lithium extraction/insertion. The component that does not participate in the reaction can be used as a matrix to buffer the volume change of the other component during the charge and discharge process, thereby improving the structural stability of the negative electrode.