A California-based energy startup called Amprius has presented the world’s highest density silicon battery for EV platforms and other applications, reaching 450 Wh/kg and 1150 Wh/L.
For comparison, Tesla’s Li-Ion battery offers an energy density of 260 Wh/kg, which is currently the best available in the industry, so someone coming out of nowhere and blowing away years of R&D from the leader in the field is incredible.
Amprius is perfecting its technology quickly, having presented a 405 Wh/kg unit only in November 2021, and promises to break a new record at 500 Wh/kg in the next couple of months. Considering the lengthy stagnation that the field has been going through for many years now, one has to wonder, how are they doing it?
Amprius has been developing a proprietary Si-Nanowire anode since 2016, to replace graphite elements inside batteries. Silicon anodes allow for ten times the capacity of traditional electrodes. However, their disadvantage is that charging causes them to expand and shrink, inevitably leading to fractures and cracks in the silicone material.
The firm’s scientists have found a solution to this problem by forming the anodes as nanowires that can expand and shrink in a controlled and predictable manner. As a result, Amprius claims that its batteries last longer than regular Li-Ion cells, and they can charge much faster too, going from 0% to 80% in just six minutes.
The first client to receive a shipment of these ground-breaking batteries is a leader in the field of HAPS (High-Altitude Pseudo Satellites), who are planning to use them in long endurance communication solutions. However, Amprius is not ready for mass production yet, as they are still looking for a site to build their full-scale facilities. This step is scheduled for completion next month, but a major ramp-up in production numbers won’t come before 2024.
