Advancing silicon anodes means innovating the silicon supply chain

August 10, 2020 | Case Study

Silicon anodes have been hyped as the next big development in Li-ion batteries. Silicon is abundant, and as an anode, silicon offers more than 10 times the specific capacity of traditional graphite. Given the promise, dozens of startups and hundreds of millions of dollars in funding have flooded the space, but silicon anodes have not lived up to the hype. According to industry players, silicon loadings are still in the mid-single digits at most and are plagued with a host of problems, such as gassing, poor cycle efficiency, short cycle life, and above all, cost. Most silicon anodes are based on silicon particles that are fabricated by ball milling and sieving metallic silicon or silicon oxide. Conversations with startups like Paraclete Energy, Nexeon, and SiILion have indicated that silicon nanoparticles synthesized this way cost more than $100/kg due to yield losses of the sieving steps and the energy intensity of ball milling. The result is a costly silicon anode that results in limited market share.