- Two US-based battery companies claim to have achieved a breakthrough in the field of silicon anodes.
- The anode is the part of the cell that stores electrons and influences the energy density.
- Automakers and electronics giants are trying to reduce their reliance on graphite for battery production.
to update: This article has been updated with comment from Mercedes-Benz.
Just like cars and gadgets, battery technology develops in stages. Sometimes you get breakthroughs, and other times things get better incrementally with small improvements year after year.
But there’s a big breakthrough on the horizon: Seeking to squeeze greater range and faster charging times from lithium-ion cells, the battery industry has long looked to replace graphite anodes — the part of the battery that stores electrons — with a better, more energy-dense material. Some battery companies like Group14 believe that the ideal replacement for graphite will come in the form of silicon. And now, they have a very good proof of concept.
Porsche supported Group14 Technologies has teamed up with New York-based battery materials company Sionic Energy to develop silicon anodes. The two companies announced joint results on Monday, concluding that their 100% silicon-carbon anodes achieved stable performance at high temperatures during charge-discharge and storage cycles. The anodes were tested in 4Ah, 10Ah, and 20Ah bag cells, with the companies claiming the cells provided stable performance at 45°C (113°F) and 60°C (140°F).
Porsche Cayenne electric battery.
Photo by: Porsche
If you’re new to the world of batteries, don’t worry, I’ll explain it in plain language. The anode is the part of the battery where lithium ions are stored during charging, and what they leave behind during discharge, when the battery is in use. The anode is primarily responsible for how much energy the cell can hold and how quickly it charges.
Graphite has long been the primary anode material thanks to its properties Stability and high energy density. However, graphite mining is dirty, expensive and poses geopolitical risks, with China continuing to be the leader in this field. The world’s largest graphite producer and exporter– Processing more than 90% of the world’s graphite as of 2023. To move away from the expensive, China-centric graphite supply chain and make Western companies more independent, battery makers have been experimenting with alternatives such as silicon and synthetic lab-produced graphite.
The anode is also the largest single component of the battery by volume, becoming the primary contributor to the weight of the pack, according to European Carbon and Graphite Association. The battery contains more graphite than lithium or cathode active materials (such as nickel, cobalt, and manganese). Replacing them with a lighter silicon anode would not only allow battery makers to reduce pack weight, it would also reduce the overall size of the battery without compromising energy density and range.
“I have spent years watching the industry pursue the promise of silicon and run into walls of complexity, cost, development time, and tight performance,” Ed Williams, president and CEO of Sionic Energy, said in a statement. “That’s why I’m proud to share this silicon standard and the Group14 partnership that breaks through those walls and accelerates widespread adoption of the silicon market,” Williams added.
Rimac high voltage battery technology
Photography: Rimac
The companies claim that silicon anodes can help a battery achieve up to 400 watt-hours per kilogram of energy density, much more than today’s common 200-300 watt-hours of energy density. They also claim that the technology is “market ready” with a life cycle of over 1,200 cycles. They recognized some disadvantages of silicon over graphite, such as electrolyte swelling, cell expansion, and irreversible capacitance fading under coercion. But in A white paper Posted online, the companies claim to have solved these issues using Sionic’s proprietary anode bond and design engineering.
Group14 claims its silicon anode can charge a battery in less than 10 minutes (depending on size and application) and deliver 55% more power compared to traditional packs. The company said the anodes themselves are “low-end,” meaning that across cell formats and chemistries, battery makers can integrate them into any manufacturing line or cell without retooling their processes. Sionic Energy has also developed a similar drop-in silicon anode, which it says will enter the electric vehicle market next year, followed by energy storage systems in 2027.
Silicon anode batteries are already starting to deliver Battery capacity explosion On high-end Chinese smartphones that would put the latest iPhones and Google Pixels to shame, without making the phones bulky.
This begs the question: Can the technology also achieve similar results in mass-market electric vehicles? Until now, technology has been limited to performance and high-end models. Group14’s silicon anode technology is housed in the 100 kWh battery pack. McMurtry Sparrowa single-seat, rear-wheel-drive supercar equipped with a downforce propeller, which can sprint to 60 mph in just 1.5 seconds, and sprint the quarter mile in eight seconds.
Mercedes-Benz said in 2022 that G-Class with EQ technology You will be using competitor Group14 Sila silicon anodes To save up to 40% energy density compared to traditional packaging. The G-Class Electric’s 116 kilowatt-hour usable battery capacity is enough for 239 miles of EPA range, which isn’t bad for a brick-shaped SUV that weighs 6,700 pounds. However, this doesn’t exactly indicate any progress in battery performance.
to update: Mercedes-Benz did not deploy the technology in the production version. This is what a Mercedes-Benz spokesperson told InsideEVs: “Since the announcement in 2022, market conditions have evolved around the world, and the partners are re-evaluating this project. Mercedes-Benz and the Sella Nano are looking at different options to bring Sella technology to production vehicles.”
However, given that this technology has already been commercialized in smartphones, a wider rollout in electric cars may not be far away. GM is also developing silicon anodesA GM executive told InsideEVs early this year that silicon batteries would help shrink battery sizes, reduce weight, and lower prices.
So, even if automakers continue to make big claims about radical solid-state technology, they see plenty of room for improvement in existing lithium-ion technology with things like graphite-free batteries, which have the potential to make EVs longer-range, faster-charging, and better than ever before.
Do you have any advice? Contact the author: suvrat.kothari@insideevs.com
