Electrical energy storage is a critical component in green energy transition from fossil fuels to renewable energy. Among a variety of energy storage solutions, Li-ion-battery (LiB) represents the most developed and reliable technology, which demonstrates high energy density and long-term durability. The deployment for LiB has been surging due to the growing market of electrical vehicles, consumer electronics and stationary storage. One of the LiB market needs is the increasing demand for higher energy density of LiB.
A great deal of effort has been made to improve the energy density of LiBs while maintaining long-term performance in academy and industry. While the energy density of cathode materials has almost reached the limit, finding the alternative anode candidate to the currently utilized graphite appears to be potentially the most feasible and economical approach towards higher energy density. Silicon was found to be an alternative anode material due to its abundancy, low price and a remarkable storage capacity for the Li ions, which could improve the battery capacity by almost an order of magnitude. However, substantial structural/morphological changes during charge and discharge cycles results in fast degradation of the batteries fabricated with Si-anodes.
The primary aim of the present project is to address the issue with Si as anode material through a scalable production process that produces engineered Si/graphene at nano scale.
So far, Silicon nanoparticles have been produced and distributed to tasks including benchmarking with conventional composition with graphite as well as combination with graphene produced by CealTech.
The present project aims to raise a new material based on a combination of silicon nanoparticles and graphene as a future anode composition for Li-ion batteries (LIBs) to a level where it can meet all the industrial requirements necessary for the successful deployment of this technology. That includes the development of the methods necessary for up-scaling the material’s synthesis/production, optimization of materials and anode properties as well as incorporation of the final nanostructured silicon/ graphene composite into industrially relevant prototype LIBs. Manufacturing perspectives such as possibility of up-scaling, assessment of material’s availability, price competitiveness and readiness for use with emerging battery technologies will be also assessed through the project.
The project will evaluate a scalable method for the preparation of silicon/graphene composites by growth of the graphene on Si nanoparticles. The prepared material in different stages of production will be subjected to extensive structural and chemical characterization in order to evaluate material morphology, coverage of coatings, quality and reproducibility, using techniques such as XRD, Raman, SEM, TEM and XPS. The material's performance as anode material will be determined by different electrochemical test procedures, including galvanostatic cycling and rate performance testing in half and full cells. Data analysis tools, like differential capacity analysis, will be used in conjunction with post-mortem analysis of materials to elucidate degradation pathways and stabilization mechanisms. The project will be finalized by verification through fabrication of pouch full celll using NMC622 as a cathode.