Silicon anodes have the potential to far-exceed the lithium ion storage capacity of carbon anodes, if only they didn’t change size so much as they absorb the ions – as this physical swelling and shrinking quickly wrecks the structure of any Si-Li-ion battery.
Plenty of companies have claimed solutions to the swelling problem, but even if they have done it, none have made it into production – despite the increased capacity that would be bestowed on the cell.
According to IFE, the technology it has developed, details of which have yet to be revealed, can achieve three to five times the charge capacity of the anode (negative electrode) compared with today’s “common graphite technology”, it said.
The organisation is in currently patenting the technology, and will work with companies to test its battery.
“We have tested that it works on a lab scale with good results,” said project researcher Marte Skare. “Now that we have received support from the Research Council in the FORNY2020 program, we will test it further with international industry partners and see if it works in their industrial processes. The project, which will focus on bringing the new material to the market, we have called SiliconX.”
What is being revealed is that its creation is the result of several years of research with nano-particles, including silicon, in IFE’s laboratories at Kjeller. “Within the nano-particles, there is a finely divided mixture of silicon and another material that we would like to call the matrix,” said leader of the SiliconX project Asbjørn Ulvestad. “This matrix will help silicon to withstand the big volume change it goes through when it is discharged and discharged.”
This graph has been released, comparing the cycle life of pure anode silicon batteries (top black curve) with a SiliconX battery (middle turquoise curve) and “commercially available anode material” (bottom black curve), said IFE. “With the developed method, you get increased stability in exchange for some of the silicon capacity. However, since this is so huge at first, it ends up with a material with 3x to 5x higher capacity than the graphite used in today’s batteries.”