Question

I am working on a project for my chemistry class that involves reading a scientifc article. The article is "A Honeycomb-like Co@N–C Composite for Ultrahigh Sulfur Loading Li–S Batteries". I have never seen the @ symbol used in chemistry. In the article they even compare Co-N-C to the cellular Co@N-C composite. So the question is what does the @ symbol mean here in the Co@N-C composite?

Answer 1

The Co@N–C composite given in the paper simply represents a type of Co-N-C composite. The paper says that this composite can trap the sulfur molecules to increase its content. This was basically done to increase the efficiency of Li-S batteries.

Here, Co@N–C means that this is specially designed composite, in which the metal is used in a specified ratio to perform a specific task. so, this is called Quasi- Composite, which is a composite like structure with desired properties. These are 2-D and quasi-materials, so these cannot be defined as proper Co-N-C composites.

With the best knowledge, This terminology is very rarely used and is not approved by any agency. So, We can take Co@N–C term as simple Co-NC composite.