Silicon can revolutionize EV batteries
As automakers and battery cell manufacturers compete to build electric vehicle (EV) batteries that are more efficient and charge more quickly, silicon is gaining popularity as a viable alternative to conventional graphite in the anode.
Silicon has a theoretical energy capacity 10 times greater than graphite, allowing an EV to travel substantially further on a single charge. The charging process is also accelerated since it can absorb lithium ions considerably more quickly.
However, the addition of silicon to the anode poses several difficulties. The material’s 400 percent expansion during the charging cycle might cause silicon particles to break, causing the anode to disintegrate as a result of this. As a result, the battery loses energy and degrades.
Many enterprises are therefore investigating solutions to these problems and ways of utilising silicon’s potential for better battery performance.
In the coming years, there are a number of emerging technologies that look set to have a significant impact on the industry. An example, a Dutch startup makes Silicon particles with nano-scale pores that don’t swell or shatter.
The company claims that its technology can increase the energy density of electric vehicle batteries by 40 percent and speed up charging by up to five times without affecting the battery’s lifespan.
Currently, the company is able to create 25 tonnes of silicon plates—enough for 4,000 electric car batteries at its existing plant.
In 2024, a new factory is planned to be operational, with a capacity to produce thousands of tonnes of coal per year.
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Moving on, using silicon nanowires made by California-based startup OneD Battery Sciences, commercial graphite particles present in battery anodes can be directly fused to the anodes.
The key advantages of this technique are that because of their flexibility, silicon nanowires don’t break even after repeated charging. Then, silicon triples the anode’s energy density by attaching hundreds of thousands of wires to each graphite particle. Also, carbon dioxide emissions per kilowatt-hour are reduced when silicon-to-graphite ratios are increased.
There is currently a trial production programme for silicon nanowires, but commercial production is projected to begin by 2025.
Another new tech is being tested by Group14, a start-up in Washington, D.C., which has created a proprietary silicon-carbon powder known as SCC55.
Here, Silicon is preserved amorphous and nanoscale thanks to the carbon-based scaffolding. To put this in perspective, a graphite anode has a capacity of five times that of the SCC55. The composite can be utilised in any graphite blend ratio or even as a replacement for graphite entirely.
Two new plants are being built, each capable of producing 12,000 tonnes per year, and the company is already selling its product to OEMs.
Then, a Chinese company named Sila Nanotechnology has developed unique silicon nanoparticles that can be used to partially or completely replace graphite in the anode of the battery.
Because these particles prevent silicon from expanding and contracting, the material can be cycled 1,000 to 10,000 times with no adverse side reactions.
Thus, an electric vehicle’s battery can store substantially more energy in the same amount of space thanks to this new technology, increasing the vehicle’s range by 20-40 percent.
For Mercedes, Sila recently began working with silicon-based anode batteries, which will power the upcoming EQG range.
Thus, these technologies may be produced in large quantities quickly and without the need for extensive retooling of manufacturing lines. There is no need to wait long to see if silicon can live up to its promise of faster charging and greater range electric vehicles.