Amprius Technologies Inc

AMPX

Amprius Technologies Inc

@Bullish_Bear
• 5 months ago

Qualitative Analysis of AMPX 10-K from Dec. 31 2024:

Hi everyone, this is my first piece of analysis on Flank! Today, I'm taking a qualitative look at Amprius Technologies (AMPX). I have a background in the Li-ion battery space, so I've been eager to share my thoughts on some of the big names in the Li-ion battery space. I'd appreciate any feedback the community might have, and I hope people find this analysis useful.

AMPX develops and manufactures lithium ion (Li-ion) batteries containing their proprietary silicon (Si) anode technology. Silicon has nearly ten times the theoretical energy density compared to traditional graphite anodes. A big challenge in commercializing these materials is the 300% volume expansion of Si upon charging of the battery, which causes the materials to crack, leading to battery degradation.

Target Industries:

  • High Altitude Pseudo Satellites (HAPS): Used for their high-quality broadcast. Rely on solar energy, storing excess energy in battery.

  • Unmanned Aerial Systems: (Drones and HAPS). Used for surveillance, logistics, delivery, communications, imaging, etc.

  • Electric Air Transportation: I am skeptical of this industry. Flying vehicles require high power output, which Li ion batteries are not known for. The 10C charging/discharging rate could make this more feasible.

  • EV/LEVs: They are currently developing batteries for EVs – but I am not optimistic. Their SiMaxx technology is very novel and difficult to scale. Good for people willing to pay the price but bad for the average consumer looking to purchase an EV. I wouldn’t count on this.

AMPX has two main Si anode technologies: SiCore and SiMaxx. Customers can purchase each in High Energy, High Power, and Balanced Energy/Power configurations. See below.

SiCore:

• 400 Wh/kg, 872 Wh/L. Max 1C Discharge Rate. 300 cycles at max charge.

• 360 Wh/kg, 800 Wh/L. Max 5C Discharge Rate. 300 cycles at max charge.

• 355 Wh/kg, 805 Wh/L. Max 3C Discharge Rate. 700 cycles at max charge, 1000 cycles at 90% of charge.

• Made with Berzelius silicon material, which AMPX has exclusive rights to purchase.

• As of Dec 31 2024: Annual Production capacity of 800 MWh pouch cells, 1 GWh cylindrical cells.

• Can be processed with industry-standard equipment for traditional graphite anodes – makes this material easy to scale up.

SiMaxx:

• 500 Wh/kg, 1300 Wh/L. Max 1C Discharge Rate.

• 400 Wh/kg, 820 Wh/L. Max 10C Discharge Rate.

o Can charge from 0% to 80% in <6 minutes – very impressive!

• 395 Wh/kg, 800 Wh/L. Max 4C Discharge Rate.

• SiMaxx technology relies on creating a “nano-wire matrix” and using chemical vapour deposition (CVD) with silane gas to coat silicon onto that nanowire matrix. This has a density of 1,000,000 nanowires/cm^2!

• This nanowire matrix allows electrons and Li ions to diffuse in straight lines through the anode rather than more “roundabout” diffusivity. This easy diffusivity is what allows the SiMaxx materials to charge and discharge so quickly – very cool!

• As of Dec 31 2024: Currently manufacturing at kWh scale. Working towards manufacturing at MWh scale in Fremont. Aim is 2 MWh capacity on completion.

Growth Plan (as of Dec 31 2024):

  • Continue leveraging rights to Berzelius silicon to keep manufacturing SiCore batteries. Given that their production of SiCore dwarfs that of SiMaxx, this seems to be their primary source of revenue.

  • Expand SiMaxx production in Fremont to 2 MWh

  • Reduce cost of SiMaxx materials. I think that customers will always have to pay a premium for SiMaxx materials since their anode synthesis is so tricky, so I don’t think you’ll be seeing this in consumer electronics any time soon. Also noteworthy is that since this SiMaxx material synthesis is still being optimized, manufacturing costs for SiMaxx are still uncertain.

  • Extend presence in aviation market

  • Further develop anode/cathode chemistries

  • Expand into EV market

Investment Thesis:

I think that AMPX has positioned itself as a strong player for Li-ion batteries for the aviation industry. There are plenty of companies which manufacture Si composite anodes. However, unlike the EV space, there are a limited number of Li ion cell chemistries which meet the specifications for aviation. AMPX believes they are the only company producing batteries which match the specification for broad aviation applications. Among these properties are high energy/power density, low operating temperature and fast charging capability.

I think that electric air transportation is not going to be relevant any time soon, so I don’t plan on viewing this as a huge part of the business. However, batteries for UAS applications are a valuable niche which AMPX serves. Therefore, to invest in AMPX is to believe that they are the best positioned company to sell Li-ion batteries for a wide variety of aviation-related purposes.

Some Concerns:

  • Cost. I believe that SiMaxx batteries will always sell for a premium due to their novel synthesis methods.

  • Number of cycles. 300 cycles seems to be around on-par for drones, but this is a far cry from the ~1500 cycles you would expect from an EV battery.

  • Their SiMaxx materials relies on CVD of silane gas. Silane gas is both toxic and highly explosive. Many research labs refuse to work with it because of how dangerous it is. As AMPX scales up SiMaxx production, the quantity of silane gas used increases, increasing the risk of accidents. I haven’t heard of any incidents related to silane gas at AMPX, but I believe that this is a tangible risk if proper safety precautions aren’t considered in scaling up.

  • They mention wanting to move into the EV space, but I see this as a bad idea. Their materials fit into a valuable niche: high energy density and high power, but high cost and low cycle life. These two drawbacks make these materials wildly infeasible for EV applications. Unless they can improve upon cost and cycle lifetime, I hope they don’t plan on investing in the EV space.

Future Works:

  • Quantitative analysis of AMPX – this should hopefully be my next post.

  • Look at other suppliers of Li-ion batteries for the aviation industry to see how their cells stack up.

  • Look at other manufacturers of Si materials – this isn’t so important since AMPX should be sticking to its niche and not an “all-purpose” Si anode, but this is still worth knowing.