Amprius Announces 10X Capacity Expansion At Its Fremont, California Battery Production Facility

Fremont, California-based Amprius technologies is the manufacturer of some of the highest energy density lithium-ion battery cells in the world. This was accomplished using their proprietary silicone nanowire anode technology that enables a step change improvement over the traditionally graphite-based lithium-ion cell chemistries.

Higher energy density and volumetric density matters when cramming batteries into products where the volume is limited and where weight is a key concern. Think aviation, drones, VTOLs, and similar applications. After going public last year in a SPAC merger that valued Amprius at $939 million, an expansion of their limited volume production facility in the Bay Area was quickly put into motion. Just a few months later, Amprius reached out to invite CleanTechnica to come up to the grand opening of their new facility.

Disclaimer: Amprius paid for the author’s travel to attend the event. 

Amprius’ pilot facility is buried in the middle of buildings occupied by none other than Tesla. We were on this same street touring Tesla’s seat factory just a few years ago and Tesla’s famed Kato road 4680 battery cell pilot factory is right next door to that. Tesla’s Fremont service center is next door with the main Tesla Fremont Factory a few miles down the road. Suffice it to say that the area has become a hotbed of innovation in the automotive and battery space over the last 10 years and Amprius is right in the middle of it.

The proximity and technological synergies were so coincidental that many thought Tesla was considering acquiring Amprius a few years ago but those rumors were quickly snuffed out by Mr. Musk himself.

Amprius’ initial breakthrough in silicon nanowire anodes was theorized back in 2008 and became a reality in 2014 when the first prototypes were developed based on the concept. The foundational building block of their high energy density and high volumetric density cells starts with a blank piece of conductive substrate. Small nanowires are then impregnated onto the substrate as a framework for the crystalline silicon structure to grow on.

After years of research and continued innovation, Amprius has refined the concept into a full fledged production line using largely off the shelf battery production equipment. They built their own proprietary production process for the steps unique to their battery which is now in its third major revision. The current production process uses production equipment from the solar cell manufacturing space with special modifications to adapt it to their needs. Amprius’ team is confident they can scale up from the kilowatt-hour scale production into megawatt-hours worth of cells at their current facility.

Right on the heels of this expansion, Amprius is working on a full blown gigawatt-hour scale production facility in Colorado. We spoke to Amprius CEO Dr. Kang Sun about the expansion. He confirmed that while the recent injection of IRA funds into the US cleantech scene were helpful, Amprius was confident the project would pay out on its own merit. This was critical to the team at Amprius as government incentives come and go but for the facility to last, it has to achieve financial sustainability without incentives.

“The expansion of our Fremont facility is an important milestone for our business as we significantly bolster our capacity to meet the increasing demands of our esteemed customers while at the same time serving more customers,” said Dr. Kang Sun, CEO of Amprius. “As we implement advanced manufacturing processes for our proprietary silicon anode cell production, we’ll be able to lay the foundation for our gigawatt-scale factory that we expect to be operational in 2025.”

As part of the ramp up of the production of Amprius’ Fremont facility, they are moving from purchasing cathodes to building them in house. As of today, Amprius’ cathode production facility is empty. The equipment was ordered months ago, but as with many things in the post-COVID world, there’s a huge backlog for the hardware. They expect to have cathode production coming online in the early part of 2024.

Amprius’ business is anchored deeply in its defense contracts with their batteries being used in micro reconnaissance drones, weapon systems, and surveillance systems. It’s not the most logical starting point for a clean tech company, but given the trillions of dollars the US continues to throw into the military, it’s great to see some innovations in clean tech being funded by the effort as well.

Looking beyond military applications, e-VTOLs and electric airplanes are also some of the beneficiaries of Amprius’ high energy density battery cells. If they’re able to fully define the production process of their advanced cells on the newly expanded end-to-end production line in Fremont, the high volumes produced at their upcoming factory in Colorado could really drive the prices down. That opens them up to even more applications like electric vehicles, electric airplanes, and more.