Startup Dive: Sakuu
3D printing meets batteries..?
This is part of Intercalation’s paid series, where we dive deeper into battery companies. In this issue, we explore Sakuu.
There haven’t been many SPACs in 2022 vs the blazing hot year of 2021, so it caught our eye when we saw Sakuu was going public via SPAC with Plum Acquisition Corp. I. in Q3 2023 especially since it seemed like it hadn’t been around very long. For comparison, it’s the third SPAC announced this year so far vs 17 SPACs in Q1 2021.
It also drew our attention as splashy EV/mobility/battery SPACs have struggled in the public markets as many of them continue to face commercial uncertainty.
The company is relatively “new” with raising its first investment round of $300k back in 2017 and has never really released much news until 2022. Today, they claim over $300m in purchase orders in 2023-25 but have yet to build a factory.
It does sound like a crazy wonderful dream to be able to 3D print a battery. As someone who almost did their PhD in 3D printing and an ex-employee at a 3D current collector startup, I was interested in all things “3D” and decided to do a write-up on what I could find online. We weren’t the only ones interested.
As listed on their website, Sakuu originally started as KeraCel back in 2017. It also looks like Keracel was formerly Verge 3D back in the day, so they've had several brand refreshes in the 5+ years.
Since their founding in 2017, they have raised over $50m in venture funding and signed partnerships with Musashi Seimitsu Industry to develop batteries for motorcycles along with a strategic investment, and supplier contracts for ceramic battery materials from NGK. They have no factory yet and are working with Porsche Consulting (recently as of Jan 2023) to design an additive manufacturing factory for the commercial production of Sakuu batteries, about to start the long journey of battery “production hell”.
Another company operating in this 3D printing battery space is Blackstone Resource, using screen printing for their “Thicker Layer Technology”.
3D Printing
3D printing can be handy for making all sorts of complex structures quickly and having some control over structure and composition. There are a few papers in the space of “inkjet printing” and “3d printing” in solid-state batteries, but we’ve shared some relevant review papers below.
Processing and manufacturing of next generation lithium-based all solid-state batteries - Wahid Zaman and Kelsey Hatzell, Princeton University
“Recently, Sakuu Inc. successfully employed their multi-material 3D printing technology to manufacture solid-state batteries in their 2.5 MWh pilot facility. Three-dimensional printing strategies (e.g., inkjet printing) need to be further explored but are unlikely for large capacity applications.”
Current Insight into 3D Printing in Solid-State Lithium-Ion Batteries: A Perspective - Ponadda et al., Indian Institute of Technology Jodhpur
“Although significant advancements are made in the 3D printing of LiBs, there still exist constraints that hinder their large-scale application. For example, electrodes prepared from conventional methods have superior mechanical properties to 3D printed techniques, associated with the anisotropic nature arising from layered deposition and high residual stress between the layers, and can be tackled by using composite materials. Rational design of porous nanostructures can lead to rapid ion transport kinetics; however, it is difficult to achieve hierarchal porous architectures via 3D printing at the nanoscale. Electrochemically active materials that can enhance the capacity of LiBs are limited.”
Fabrication of modern lithium ion batteries by 3D inkjet printing: opportunities and challenges - Sztymela et al., CNRS
“Not only can novel three-dimensional electrodes with high accuracy be created, but also thin-film electrodes, which often yield greater electrochemical performance than those deposited by conventional tape casting techniques. However, formulating a suitable ink, which may be successfully deposited using the IJP method, is challenging. The properties of a slurry impact not only the final product's performance, but also the printability. A suspension that is not properly tailored can impede the ejection, making the process impossible.”
Some selected examples of 3D printing of battery materials in research:
McOwen et al. from the University of Maryland demonstrated liquid ink printing of Ca- and Nb-doped Li7La3Zr2O12 (LLZ) garnet-type SEs.
Gu et al. from the New Jersey Institute of Technology demonstrated printing LFP thin films using a Fujifilm Dimatix inkjet printer.
Maximov et al. from SPbPU demonstrated the printing of NMC cathodes.
Stephen Lawles demonstrated ink printing of silicon anodes in his PhD dissertation.
Technology
Sakuu has several claims on its website. One of the central claims is their 3D printing technique which they call Kavian. We focus on the claims that we could hone in on with data from other publicly available sources or patents.
