Incorporating silicon into the anodes of electric vehicle (EV) batteries can result in lighter and longer-range batteries. However, this process requires large volumes of silane (SiH₄) gas, the vast majority of which is currently produced in China. Now, a new partnership between OneD Battery Sciences (Palo Alto, Calif.; ) and Koch Modular Process Systems, LLC (Paramus, N.J.; ) is bringing together onsite silane production with the manufacture of silicon-graphite anode materials to create the first integrated North American plant to produce silicon-graphite anode materials. The key to this project is a unique modular process to produce silane developed by Koch Modular. “Silane is typically shipped in tube trailers, which weigh a huge amount compared to the volume of silane gas they carry, making it very expensive to ship at the quantities required to make batteries,” explains George Schlowsky, president of Koch Modular. By integrating modular silane production into OneD’s Sinanode process for converting silane into nanosilicon inside EV-grade graphite materials, battery production costs can be significantly reduced. In addition, range and charging speed are increased.

One key element of the Sinanode technology is a low-cost catalyst to decompose the silane, extracting the silicon and exhausting the hydrogen. “We have designed a way to make trillions of uniform nanoparticles of copper oxide floating in deionized water, at an incredibly low cost,” explains Vincent Pluvinage, CEO of OneD. When mixed with graphite, the catalyst will deposit onto the graphite, leading to very fast decomposition of the silane. Another key element of the Sinanode process is that it employs inexpensive equipment that is widely used in the solar industry. “In the part of the machine where you would normally insert a solar-cell wafer, we put a reactor with catalyzed graphite where we inject silane and nitrogen, and the silane decomposes into nano-silicon inside the graphite pores,” says Pluvinage.

The new integrated plant is anticipated to produce around 20,000 tons/yr of silicon-enhanced EV-grade graphite, eventually scaling up to 40,000 tons/yr. OneD has been operating a single-tube reactor since 2018, producing up to several tons per year, and in April, the company is starting up a 100-ton/yr unit in Moses Lake, Wash.