A novel composite material which includes silicon and carbon, the amount of silicon being 1-80 wt.-% and at least 90 wt.-% of the composite material being in a density range between a lower density threshold value p*1 and an upper density threshold value p*2. The density threshold values have the following relation: ρ*1,2=(1±δ)·ρ, wherein ρ is the mean density of the composite material and ±δ is the variation range between the upper density threshold value ρ*2 and the lower density threshold value ρ*1, the amount of δ being