US scientists replace platinum in solar cells with new materials

According to the report of the Physicist Organization Network on August 21 (Beijing time), scientists at Michigan Technological University in the US claimed that they have developed a low-cost cathode material that can replace the precious metal platinum that was previously required in the production of dye-sensitized solar cells. Related research was published online in the scientific journal Applied Chemistry (International Edition).

Dye-sensitized solar cells have the characteristics of good stability, high theoretical efficiency, simple process, and friendly production environment, and are considered to be the most promising of many new solar cell technologies. The flexible solar cell based on it has a good flexibility, light weight, and easy production on a large area, which is a hot topic in recent years. However, before large-scale promotion and application, the technology still has many obstacles that need to be cleared. Precious metal platinum is one of them. Although platinum is not used in the manufacture of dye-sensitized solar cells, its price of US$1,500 per ounce has, to a certain extent, pushed up the price of the final product, which has made it more difficult to promote large areas.

For this reason, Hu Yunhang, a professor at the School of Materials and Engineering at Michigan Technological University in the United States who is in charge of this research, specially developed a new material that can replace platinum, which the researchers called cellular 3D graphene. To create this unique structure of graphene material, Hu Yunhang's team chemically reacted lithium oxide with carbon monoxide to produce a mixture of lithium carbonate (Li2CO3) and honeycomb graphene. Then, the acid is used to remove the lithium carbonate particles in the entire structure, leaving honeycomb graphene.

The researchers found that this honeycombed 3D graphene has excellent electrical conductivity, high catalytic activity, and great potential for energy storage and conversion. To confirm the conjecture, they replaced the platinum electrode in the dye-sensitized solar cell with a honeycomb 3D graphene electrode. The measured results under the same sunshine conditions show that the photoelectric conversion efficiency of solar cells using the new material is 7.8%, which is very close to that of the conventional dye-sensitized solar cells using platinum.

Hu Yunhang said that it is neither difficult nor expensive to synthesize this honeycombed 3D graphene, which is an ideal material for the manufacture of cathodes. We will continue to study in the future with a view to further improving performance. (Reporter Wang Xiaolong)