The lacklustre energy density of batteries is one of the biggest obstacles to widespread vehicle electrification. Current lithium-ion batteries used in most electric vehicles usually are a significant percentage of an EV’s weight. The Ford F-150 Lightning weighs around 2,948 kg. The electric pickup truck’s battery weighs 816 kg alone. The large size of batteries increases costs and reduces range. However, silicon anode batteries could drastically change the nature of electrically-powered transportation.
Silicon anode batteries replace the graphite anode of a lithium-ion battery with silicon. Amprius Technologies claims that its silicon anode batteries will have an energy density of 450 watt-hours per kilogram. Conventional lithium-ion batteries have an energy density of 270 Wh/ kg. CNBC looked into challenges holding back the revolutionary concept and the possibilities it could unlock in the near future.
The primary issue with silicon anode batteries is cracking. The battery swelling over only a few charge-discharge cycles causes the cells to crack. Though, development at multiple companies is aimed at resolving the problem. Porsche and Mercedes have invested in silicon anode ventures. The 2024 Mercedes-Benz EQG will be the automaker’s first EV to feature silicon anode technology.
It’s difficult not to be drawn to the potential of silicon anode batteries. Yi Cui, a energy science professor at Stanford University, told CNBC that the technology could double the range of existing EVs. Also, Amprius claims its batteries can charge to 80 per cent in six minutes. Manufacturers would be able to shrink battery packs and use them in a wider variety of vehicles, like airliners and freight trucks. Most importantly, silicon is one of the most abundant elements in the world.
Over here in Australia, while other countries look to find new ways to make batteries, we have only just had our first EV strategy plan handed down from the government. In it, the government highlights six key outcomes it wants to achieve to increase the uptake of EVs in Australia.
These outcomes are around national standards, data sharing, affordability, remote and regional charging infrastructure, fleet procurement and education and awareness.