After initially focusing on securing supplies of lithium, manufacturers in the rapidly growing US battery industry are turning their attention to less-well-known components, such as graphite and manganese. The US doesn’t make these materials in large volumes, and several companies are trying to increase production to meet demand from battery makers.
Anovion announced in May that it plans to build an $800 million plant in Georgia, funded partially by a US Department of Energy grant, to produce synthetic graphite, which is made from needle coke instead of mined graphite flakes. Novonix recently agreed to work with LG Energy Solution on a synthetic graphite production process. If successful, LG would buy the synthetic graphite from a proposed US facility.
Then, in June, Epsilon announced plans for a $650 million facility in the US that would produce 50,000 metric tons (t) of synthetic graphite annually. Another firm, Graphex Technologies, has received an environmental permit for a graphite facility in Michigan.
Nearly all lithium-ion batteries use graphite in their anodes, the negative end of a battery. But most graphite for electric vehicle batteries is mined and processed in China, according to an International Energy Agency report.
US battery makers are eager for a local source of graphite, according to Evelina Stoikou, energy storage associate with the research firm BloombergNEF. She says new tax credits encouraging production of US-made battery materials are making it easier to meet that demand. “A lot of companies are jumping on that,” Stoikou says.
Battery makers also continue to look for ways to reduce the cost of cathodes, the positive end of a battery and the most expensive component. One option is to replace nickel with less expensive manganese. In addition, adding manganese to lithium iron phosphate batteries, which are cheaper than nickel-based batteries, can boost energy density.
The US hasn’t produced manganese ore since the 1970s, but in May, a US agency decided to fast-track permits for South32’s manganese and zinc mining project in Arizona. In June, General Motors announced that it would provide an $85 million loan for Element 25’s manganese sulfate facility in Louisiana, which would be the first such plant in the US. GM has agreed to buy up to 32,500 t of the plant’s annual output, produced using ore from Australia.
Manganese is a promising material because it can improve existing battery chemistries without requiring manufacturers to adopt new technology, Stoikou says. Mining manganese in the US could be a challenge, though. The US Geological Survey notes that US manganese ores are poor quality and expensive to extract.
Still, Stoikou says companies in the US are motivated to simplify all parts of the battery supply chain to ensure smooth operations. “Battery manufacturing plants are going to need input materials,” she says. “It would help logistically to get them from somewhere within North America.”