Future Li-ion batteries
Si storage capacity can be as high as 4200 mAh/g but in practice limited to 3579 mAh/g for the Li15Si4 form. This is however 9 times higher than graphite.
An active material containing 20% Si and graphite would then have a capacity of 1000 mAh/g.
The substitution of graphite by silicon/carbon composite will save 60% graphite either natural (critical ressource) or artificial (high temperature process).