California start-up Amprius, founded in 2008 by Professor Yi Cui of Stanford University, is slowly beginning the commercialization process of lithium-ion batteries with silicon anodes.
For now, this technology is limited only to consumer electronics, but this could be the beginning of breakthrough battery tech for electric vehicles.
Right now, Amprius is making first generation cells with a capacity of either 1850 mAh or 4060 mAh. These cells are currently being to supplied, in low volumes, to manufacturers of smartphones and tablets.
Techy Graphical Display of Amprius' Goals
Amprius says it batteries meet the needs of electronics manufacturers in terms of durability. The cells can handle more than 500 charge / discharge cycles with a loss of roughly 20% of the initial capacity. Rapid decrease in capacity had been the main barrier preventing the commercialization of cells with silicon anode, even though theoretically they offer at least 2-3-fold higher energy density.
Ready for that tech speak again? Okay, here goes: The first wave of cells have volumetric energy density of 580-600 Wh/L depending on cell size, noticeably more than most all lithium-ion cells with a carbon anode. Amprius hopes to use nanowires in next-generation silicon anode batteries to increase that figure to 650 or 700 Wh/L. Nanowires will also help address the issue of silicon swelling up to 400% when charged, which means the next-gen cell should be able to withstand thousands of cycles.
Quote time. Dr. Kang Sun, Amprius CEO, had this to say of the battery makers work:
"Amprius is excited to work closely with OEM manufacturers to make high energy battery technologies available to consumers. We will soon increase our manufacturing capacity to meet increasing customer demand for our high capacity and high energy density batteries."
"We continue to focus on silicon anode-based technologies. Amprius is also collaborating with Professor Yi Cui’s lab at Stanford University and industrial partners worldwide to develop high energy density cathodes, advanced electrochemical systems, high performance separators, and innovative manufacturing processes."