Cost remains one of the biggest barriers to electric vehicle adoption. Most of today’s EVs sell for higher prices than fossil fuel vehicles, and this prevents many people from buying one.
That may change soon. Coreshella battery materials startup, revealed a breakthrough this week that could lower the cost of lithium-ion batteries.
It wouldn’t be the kind of advancement that unlocks 500-mile range electric vehicles, but not many people need that kind of capability. If Coreshell’s approach can prove its worth, it could pave the way for cheaper batteries that don’t depend on China.
Predictions of cheaper electric vehicles are based on a steady stream of technological improvements, including better battery materials. Silicon has the potential to replace graphite in the anode, the negative pole of a lithium-ion battery. Both silicon and graphite accept and store lithium ions when a battery is charged. While silicon can hold much more, there is a downside.
During charging, the anodes tend to swell. The graphite anodes just puff up a bit and are pretty springy to boot. But when silicon anodes are charged, they can inflate like balloons to many times their original size. Without something to compensate for this, the anode can break down after successive charge and discharge cycles.
However, silicon’s potential to improve batteries has many startups working to solve its problems. Most approaches involve specialized microscopic structures to accommodate silicon’s tendency to expand. To make their proprietary formulations, these companies use a more refined and more expensive version of the metal. As a result, silicon anodes have so far been targeted at markets where the price premium can be more easily absorbed, including consumer electronics and high-end electric vehicles.
Coreshell previously focused on coatings that slowed the degradation of various battery materials, but now the company is committed to silicon. “Two years ago, we had a breakthrough in metallurgical grade silicon,” co-founder and CEO Jonathan Tan told TechCrunch. The coating is elastic, helping to hold the material through charge and discharge cycles and also prevents surface degradation, he added. “It will be what we are focused on bringing to market and we will commercialize it from next year.”
Metallurgical-grade silicon is not only cheaper than higher-purity options, it’s also about half the cost of graphite commonly used in lithium-ion batteries, Tan said Thursday in a presentation at the International Battery Seminar.
There are also geopolitical ramifications. Three-quarters of the global graphite anode supply chain runs through China, according to Mineral Intelligence Benchmark. This has put battery manufacturers and automakers in a difficult position. To qualify for tax credits on EVs, the Inflation Reduction Act requires a minimum percentage of battery materials to be domestically sourced or from countries with which the US has a free trade agreement. this share is scheduled to increase to 90% in 2028.
Because silicon can store much more energy, batteries of equivalent capacity require less material compared to graphite. Given this, Coreshell estimates that the United States should have enough metallurgical silicon to meet demand. And because metallurgical silicon also costs less than graphite, it has the potential to completely replace Chinese graphite.
Coreshell’s first product will be a silicon anode combined with a lithium-iron-phosphate (LFP) cathode. LFP cathodes are cheaper and safer than other chemicals used in electric cars, such as nickel-manganese-cobalt (NMC), and the components are more widely available outside of China. Because of this, automakers have given LFP a second look, but have shied away from deploying it widely because it stores less energy than NMC.
However, when combined with a silicon anode, the difference should disappear. Coreshell predicts that its silicon anodes could even give the LFP an advantage over traditional NMC cells with a graphite anode.
First, Coreshell needs to scale and commercialize its technology, which is no small task. Its initial market will be e-mobility, including e-bikes, electric scooters and electric sand dunes. (The company has a deal with the reincarnation of Meyers Manx, which made the iconic 1960s dune of the same name.) For now, the company makes its own stuff, but isn’t averse to working more closely with suppliers , perhaps by licensing its technology.
In the meantime, Coreshell will go through the rigorous certification stages required to become an automotive supplier. Tan said his company plans to supply A samples to partners in 2025 and hopes to be in an EV by the end of the decade. By 2025, competitors Sila and Group14 expect to be in commercial production. Granted, their silicon anode materials will cost more, but they will have the benefit of scale and experience to help keep costs down.
For automakers, the prospect of choice is attractive. Not all battery advances make it through validation, and if lithium-ion is to continue its journey down the cost curve, it will take more than one approach to achieve the incremental advances the automaker is counting on.
