Silicon Anodes vs. Solid-State Batteries with Graphite Anodes: The Race is On and Silicon is Ahead

 

     Silicon anodes on EV batteries can improve power and charging times. Apparently, the hype around solid-state batteries has faded as timelines keep stretching out. The adoption of silicon anodes may precede solid-state batteries in the non-luxury commercial market. However, there are still important challenges left to be addressed about silicon anodes including cycle life, shelf life, and cost. According to CNBC, Venkat Srinivasan, director of the Collaborative Center for Energy Storage Science at the U.S. government's Argonne National Laboratory in Chicago noted that five years ago silicon anodes had a shelf life of just one year, but recent tests have upped that to three or four years. Typically, the calendar life of a battery denotes the period in which it can function at over 80% of its initial capacity, regardless of its usage. Graphite-based anodes are in common use. Theoretically, silicon anodes can offer ten times the energy density of graphite. Silicon anodes have a tendency to swell when charging which leads to their loss of longevity. Some solid-state battery developers say that electrolyte improvements will make that difference in energy density less important. Right now, silicon anodes and solid-state batteries are in competition as next-generation technologies and both may be on the market soon.

     There are, however, other reasons to invest and develop silicon-based anodes. According to Georgi Georgiev, battery raw materials analyst at consultancy Fastmarkets, as told to CNBC:

“Especially in the West, advances in the area of silicon anodes [are] seen as strategic opportunity to catch up with China, which dominates the graphite-based anode supply chains with Chinese anode producers holding 98% of the global anode market for batteries.”

“However, there are significant technical challenges going to 100% silicon anode such as silicon expansion affecting the longevity of the batteries and currently there are several routes to produce silicon anodes.”

     Taiwanese battery maker ProLogium unveiled the world's first fully silicon anode battery at the Paris Motor Show in October 2024.

 

“ProLogium, citing test data, said it's 100% silicon anode battery could charge from 5% to 60% in just 5 minutes, and reach 80% in 8.5 minutes. It described the advancement as an "unmatched achievement in the competitive EV market," which will help to reduce charging times and extend the range of EVs.”

     Georgiev also questioned whether OEMs could produce the anodes at scale with consistent quality and at a competitive cost. He also noted that it is more likely that silicon anode material will likely be used in conjunction with graphite, presumably in a kind of material hybrid fashion.

“At this stage silicon anodes are used more as an additive to graphite-based anodes and in the years to come we expect to see increase of silicon share in anode, but in combination with graphite, while 100% silicon anodes will take longer time to enter the mass market.”

 

 

Group 14’s Silicon Anode Production

     According to Emily Dreibelbis Forlini in a May 2024 article for PC Magazine:

“Group14 is already shipping its patented black powder, dubbed SCC55, by the ton to companies that are testing in their products. With big names like Huawei, Hyundai, Kia, Volkswagen, Audi, Porsche, BYD, and Panasonic potentially on its customer list, and two full-scale plants under construction, we may finally see these next-gen batteries in products by the late 2020s.’

     Group 14 silicon anodes are already in mobile phones in China, possibly phones from Huawei, as rumors indicate. They are also sending their black powder to China’s ATL for use in smartphones. They are also likely shipping the black powder to Kia and Hyundai.

 Fortini describes the process:

“First, they put "two commercially available products" through a reactor to create a carbon solution, which looks a bit like volcanic ash. Second, they mill that carbon down to a small molecule, or "the perfect nano spec." Third, the milled carbon goes through a second reactor to inject silane (a gaseous form of silicon) into it. The molecule now has carbon, silicon, and "void space," or extra room Group14 has engineered into the materials that allow them to expand and contract without busting out of the battery pack, a problem for silicon batteries in the past.”

     Following some quality control protocols, the powder is then bagged up and shipped out.

     Silicon is cheap and available from the U.S., Asia, Europe, and South America while 70% of graphite is sourced from China. This gives it a clear geopolitical advantage. One remaining challenge is scaling up production to meet the large demand expected from EV manufacturers.

Group 14’s Grant Ray “claims "nearly all" major automotive OEMs have received shipments of SCC55, some by the ton—a sign of widespread, near-commercial readiness, as opposed to a small, isolated lab test. They're putting it in cars on the road, just not ones we can buy yet.”

He also noted that Group 14 was in testing with 95% of battery manufacturers. Group14 also purchased a silane gas company in Germany. Ray also expects vehicles with Group14-powered batteries to be at auto shows starting in 2025, likely first in Asia. Along with Group 14 other companies focusing on silicon anode development include Sila and Amprius Technologies.

 

 

References:

Solid-state batteries may yet catch up — but silicon anodes are winning the race to power EVs. Sam Meredith. CNBC. November 5, 2024. Solid-state batteries may yet catch up — but silicon anodes are winning the race to power EVs

The silicon battery age starts here. Group 14. Group14 | Powering the Silicon Battery Age

48. Sila. Disruptor 50 2023. CNBC. May 9, 2023. Sila: 2023 CNBC Disruptor 50

Is This Black Powder the Secret Solution to EV Charging Woes? Emily Dreibelbis Forlini. PC Magazine. May 3, 2024. Is This Black Powder the Secret Solution to EV Charging Woes? | PCMag