Evonik has introduced the silicon-carbon composite material Siridion Black as a new anode material for lithium-ion batteries. Siridon Black features an amorphous Si/C structure with a unique carbon concentration gradient for superior stability and a high specific capacity of more than 3,300 mAh/g.
The Si/C composite increases the energy density and energy efficiency of lithium-ion batteries while maintaining a practical service life.
The introduction of the new high-performance material completes Evonik’s range of battery materials: the company already offers cathode active material and fumed metal oxides for the coating of separators.
Sirdion Black, Evonik’s Si/C composite powder: transmission electron microscopy image (left) and schematic representation of the Si/C structure with carbon concentration gradient (right). Source: Evonik
The powder is produced by gas phase synthesis. It consists of isolated unsintered spherical particles that are a few hundred nanometers in size. Within the amorphous particles, the carbon concentration increases from the inside out.
In addition, due to the higher carbon content on the surface, the particles are better protected against oxidation and easier to process. Our Siridion Black enables customized solutions: It gives anode manufacturers and their customers the necessary flexibility to adapt their batteries exactly to their respective needs.—Dr. Julia Lyubina, responsible for the development and commercialization of Siridion Black
The high performance anode material was jointly developed by the Research, Development & Innovation Function and the Silanes Business Line of Evonik. They are working on making lithium-ion batteries even more powerful in a joint project with the University of Duisburg-Essen that is being funded by the German Federal Ministry of Economic Affairs and Energy until 2023.
The carbon-covered silicon is now available on an industrial scale. It will be showcased to the public at the China International Battery Fair, which will take place from 19 to 21 March in Shenzen, China.