Composite materials, positive electrode and battery

Abstract

The composite material of this invention comprises a carbon-sulfur composite and a protective layer formed on the surface of the carbon-sulfur composite. The carbon-sulfur composite includes a porous carbon material and a sulfur material supported on the porous carbon material. The protective layer is composed of at least one of non-graphitic carbon and a carbon precursor, has a film thickness of 1.0 nm or more, and a crystallite size Lc of 1.0 to 4.0 nm.