General Discussion, page-2117

Are you sure?

Given there's around a 10:1 ratio on the theoretical capacity of Silicon vs graphite, if they have managed to develop a product with double the Wh/kg of standard batteries it a far from a pure silicon Anode. Given they are using silicon nanowires, what are the nanowires attached to?

OneD is an outfit creating silicon nanowires for batteries. What I think OneD have done is basically take spherical graphite and put a furry coat of nanowires around it. This creates a separation gap between the graphite core's providing the space necessary for the silicon nanowires to expand and contract with as they collect and lose a charge because they need space as they change shape on charging and discharging.


The article below discusses how OneD Battery science have a commercial process that will produce SINANODE, a silicon nanowires product for use in batteries. They appear to have found a scalable commercial process that enables increased silicon content to be attached to a graphite "powder". The article references the graphite powder costing $8/kg. This is the sort of price point I'd have expected if they were using synthetic spherical graphite, which does indeed look like a powder (except under a microscope and aligns to the picture above). At $8,000/t they are using a precision product that is something more advanced than graphite fines simply reduced to a small micron size. Lets recall that EGR is modelling is $4/kg ($4,000/t) for its purified natural graphite. The article then explores the economics and has the silicon nanotube product at a $16/kg price point ($16,000/t). While the silicon is cheap, the process and other materials required to create the nanotubes and have them attaching to the graphite isn't.

So in their worked example at the end, graphite reduces from 100% to 80% of the Anode but in blending in the more expensive graphite product with an even higher storage capacity silicon product means they get an improvement in the Ah for each dollar spent. If you are using 80% graphite in a top-end anode product, that still is 80% of the anode being graphite and creating demand for graphite. If there is demand for 357Ah/kg graphite at $8/kg there should be demand for EGR's natural spherical graphite at $4/kg ($4,000/t) particularly if it delivers 361.1Ah/kg vs 357Ah/kg for the product the researchers used.

Basic-Facts-on-CVD-techniques-to-Grow-Silicon-nanowires-OneD-Material.pdf (onedsinanode.com)
https://onedsinanode.com/wp-content/uploads/2021/05/Basic-Facts-on-CVD-techniques-to-Grow-Silicon-nanowires-OneD-Material.pdf