Cost remains one of the biggest obstacles to electric vehicle adoption. Most current EVs sell for higher prices than fossil fuel-powered cars, which prevents many people from purchasing them.
That may change soon. Battery materials startup Coreshell this week unveiled a breakthrough technology that could lower the cost of lithium-ion batteries.
It's probably not the kind of advancement that would make an EV with 500 miles of range possible, but not many people need that kind of capability. If the core-shell approach proves its worth, it could pave the way for cheaper batteries that don't rely on China.
Forecasts for cheaper EVs call for steady technology improvements, including better battery materials. Silicon has the potential to replace graphite in the anode, the negative electrode in lithium-ion batteries. Both silicon and graphite accept and store lithium ions during battery charging. Silicone can hold more, but it also has its drawbacks.
When charging, the anode tends to expand. Graphite anodes only swell a little and are quite resilient. However, when a silicon anode is charged, it can expand several times its original size, like a balloon. Without something to compensate for this, repeated charging and discharging can damage the anode.
Still, silicon has the potential to improve batteries, and several startups are working to solve the problem. Most approaches involve special microstructures that accommodate silicon's tendency to expand. These companies use more refined and expensive metals to create their proprietary formulations. As a result, silicon anodes have traditionally been targeted at markets that can easily absorb price premiums, such as consumer electronics and high-end electric vehicles.
Coreshell has previously focused on coatings that slow the aging of various battery materials, but is now focused on silicon. “Two years ago, we made a breakthrough in metallurgical grade silicon,” co-founder and CEO Jonathan Tan told TechCrunch. The coating is elastic, which helps hold the material through charge and discharge cycles, and also prevents surface degradation, he added. “This is something we are focused on bringing to market and will commercialize starting next year.”
Metallurgical-grade silicon is not only cheaper than high-purity silicon, but also about half the cost of graphite typically used in lithium-ion batteries, Tan said in a presentation at the International Battery Seminar on Thursday. .
There are also geopolitical implications. According to Benchmark Mineral Intelligence, three-quarters of the world's graphite anode supply chain passes through China. This has put battery manufacturers and automakers in a tight spot. To qualify for EV tax credits, the Inflation Control Act requires that a minimum percentage of battery materials come from domestic sources or from countries with which the U.S. has a free trade agreement. Its share he plans to increase to 90% in 2028.
Because silicon can store so much energy, a battery of comparable capacity requires less material than graphite. With that in mind, CoreShell estimates there should be enough metallurgical silicon in the U.S. to meet demand. Metallurgical silicon is also cheaper than graphite, so it could completely replace graphite in China.
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 EVs, such as nickel manganese cobalt (NMC), and the ingredients are more widely available outside of China. As a result, automakers are reconsidering LFPs, but are holding back on widespread adoption because they store less energy than NMCs.
However, when combined with a silicon anode, the difference should disappear. Coreshell predicts that the company's silicon anode could give his LFP an advantage over his traditional NMC cells with graphite anodes.
First, Coreshell needs to scale and commercialize its technology, which is a non-trivial task. Its first market will be electric mobility such as electric bikes, electric scooters and electric dune buggies. (The company has a deal with the reincarnation of Meyers Manx, the company that made the iconic 1960s dune buggy of the same name.) For now, the company is manufacturing its own materials, but will likely use licensing, etc. , are not opposed to working more closely with suppliers. That technology.
Meanwhile, Core Shell will go through the rigorous qualification stages required to become an automotive supplier. Mr Tan said his company plans to supply A samples to partners in 2025 and hopes to have them in EVs by the end of the decade. By 2025, competitors Sila and Group 14 are scheduled to begin commercial production. Admittedly, the company's silicon anode materials cost more, but it offers benefits of scale and experience that help reduce costs.
For automakers, the possibilities for choice are attractive. Not all battery advances pass validation. If lithium-ion continues to move down the cost curve, multiple approaches will be needed to achieve the incremental progress the auto industry is hoping for.