Why TDK Ventures Invested in AM Batteries and Their Dry Electrode Technology

This story is contributed by Anil Achyuta from TDK Ventures.

  • With rapid electrification, the global manufacturing capacity of lithium-ion batteries is poised to increase from 325 GWh to around 1500 GWh in the next 10 years. With this capacity rise, the need for sustainable manufacturing solutions that consume less energy and hence emit less CO2 would become paramount
  • We reviewed the current landscape of key innovations in the sustainable manufacturing space and realized dry electrode technologies not only offer a way to reduce energy consumption in the battery cell making process (hence lowering the cost) but such innovations could also allow opportunities to augment the performance of today’s lithium-ion batteries in the near term
  • In the future, battery manufacturers will likely not only differentiate on energy density or cost improvements, but also on kg of CO2 emitted per kWh, which is a measure of the environmental footprint of such a process. AM Batteries offers a potentially game-changing dry electrode technology in achieving these goals with clear milestones towards mass production

Historical Perspective

Electric vehicles (EV) are defined as any mode of transportation where electric power facilitates the work necessary to drive motion and move us forward, as well as being capable of carrying some loading capacity, often times ourselves, from point A to point B. In contrast to most power plants wherein the electric power is harvested from some sort of mechanical motion, in the case of today’s EVs, the electrical energy is derived from the use of a battery-converted, stored chemical energy to electric energy. As is shown in basic detail in Figure 1, this involves a high capacity (chargeable) battery connected to an electro-mechanical converter to induce rotary motion in the wheels upon command.

When EVs are thought of today, images and media stories regarding the rise of Tesla as a titan in the field immediately come to mind, as well as some other pacesetters that have led the way in recent years — such as the Chevy Volt, Nio technologies, or even the Toyota Prius hybrid released in 2000. While these are some of the major players of the day — and Elon Musk’s role cannot be overstated — electric vehicles have actually been a long time coming. It’s difficult to provide an exact date, but inventors had come up with roadworthy electric vehicles as early as the first half of the 19th century (early 1800’s). They initially appeared alongside steam and gasoline alternatives, with Ferdinand Porsche even creating an electric P1 in 1898. However, the focus quickly shifted to gasoline engines, when Henry Ford was able to undercut affordability by being 37% of the cost of an electric vehicle1.

From that point onward, the market had spoken, and the gasoline engine became the name of the game — including taking the lion-share of media attention, engineering development, and R&D resources. For a while, it seemed the idea of electric cars would be no more than a science project until the 1970–80s brought to critical attention the dangers of gas dependence, resource shortages, and the beginnings of the environmental mindfulness movement. One of several responses to this was a Department of Energy directive encouraging EV research and seeking alternatives to oil-heavy technology (Electric and Hybrid Vehicle Research, Development, and Demonstration Act of 1976).

With incentives finally pushing progress, the technological challenges slowly became clear in the following decades, which all came down to a single lynchpin — energy density. The key milestone to viability for EV technology was to develop battery technology or battery output similar to that of a gasoline engine alternative of comparable scale (both size and weight). Following suit, much of EV research then symbiotically focused on improved battery development, getting the energy demand to par — or refining car designs and reducing the energy potentially required.

Enter lithium-ion battery (LIB) technology

British-American chemist Stan Whittingham first proposed Li-ion batteries in the 1970s. American materials scientist John Goodenough developed cathode materials in the 1980s. Japanese chemist Akira Yoshino developed the first commercial lithium-ion battery in the 1990s. Together, all three of them won the Nobel Prize in Chemistry in 2019. Li-ion batteries have almost 4x the energy/unit mass and nearly 7x the energy/unit volume when compared to traditional lead-acid car batteries, on top of 3x the voltage capacity.

The makeup is fairly straightforward as is illustrated in Figure 2. A positively charged material (cathode) is placed against a separating barrier from a negatively charged (anode) material. When an electric load is introduced connecting the anode and cathode, Lithium ions flow from negative to positive, imparting a discharging current. When this load is removed and a current is given to the system, the Lithium ions flow back to the anode “charging” the system — thus rechargeable.

The energy properties of LiB are of incredible quality and enable the necessary power for EV’s to be a true competitor against gasoline vehicle technology, when performance, value, and clean energy are considered. Their innovation in the use of LiB in EVs is what has driven Tesla to the top and brought them wide acceptance as the current king player in the developing EV space — gaining enough traction to even convince Chevy and GM to join the game and contribute to progress in this technology area. This takes us to now. Technology is beginning to mature and businesses are taking notice. However, rapid progress has brought with it the realities of scaling and the growing pains that must be overcome for the industry to blossom as most projections indicate.

Current State of the EV/LIBs Manufacturing World

The market is literally exploding. Projections expect the manufacturing of EVs to hit 10M/year by 2025 and up to 60M/year by 2040 — with China as the distinct leader. This intrinsically will spur the development and increased capacity of Lithium-ion batteries to keep pace. Over 2,000 GWh is expected to be in demand by 2030 with over 1,400 GWh of that dedicated to passenger vehicles alone. In comparison, manufacturing capacity is only projected to break around 1,500 GWh by 2030 — signaling a huge demand (Figure 3).

To achieve the capabilities and capacity necessary, the first step is rapid and quality manufacturing of lithium-ion batteries — which is a problem. The current standard for LIBs manufacturing is complex. To summarize, the process begins with mixing cathode (or anode) active powder with polymer binder and conductive additives in wet solvent as a slurry solution, which is then “poured” to coat the current collectors. Now properly in place, the mixture is subjected to several rounds of drying to remove the solvent, after which it is subjected to extensive further processing — such as calendering, slitting, vacuum drying — to create battery electrodes. These battery electrodes are then stacked, enclosed, formed, aged, and finally assembled into the end-product, which is called a battery cell. This process is visualized in Figure 4.

Figure 4. Process of wet electrode manufacturing for LIB provided by Liu et al. iScience24, 102332, April 23, 2021.

With so many moving parts, this process has plenty of pain points, which have plagued the industry. However, the most expensive are by far those associated with wet-slurry coating — specifically drying of the N-Methylpyrrolidone (NMP) solvent. The capital expenditure is massive with drying equipment possibly taking up to 80 meters in length, and the solvent itself is inherently toxic, requiring operational expenditures and safety hazards which are just as draining on resources. In fact, it is estimated up to almost $46 per pack or $1.12 per kg of NMP is spent on NMP recycling alone, which can easily add to millions of dollars in cost per year.2 It is important to note this is a pervasive problem and affects all of those in the EV and battery technology industries.

Elon Musk has brought some notoriety to this particular issue saying, “Dry electrode is a key piece (one of many pieces) of the puzzle for lowering the cost of lithium batteries,”3 while addressing the Tesla selloff of Maxwell technologies though retaining their dry electrode methodologies. Despite having their technology since the original purchase in 2019, it still appears there are ways to go as Musk also stated, “Maxwell’s dry coating was sort of a proof-of-concept. Post-acquisition, we have revised this process at least four times and there’s still a lot of work to do. These things work well in lab-scale, but to go from lab to pilot to mass production, it is insanely difficult to scale-up.”4

In examining the industry as a whole, investments in batteries have been almost purely focused on improving chemistry and not as much on manufacturing innovations to address the issue described above. Seeing the huge potential of these technologies to improve and encourage the transition to sustainable energy, we at TDK ventures have decided to focus our strategy on this manufacturing aspect — particularly dry-electrode technologies.

TDK Ventures’ Strategic Outlook on EVs and LIBs Manufacturing Process Innovations

So, why have we invested the way we have?

Motivated by the potential for greater sustainability, we began scouting for potential technologies that could bring about a paradigm change to the manufacturing process — specifically the wet-coating problem. We identified several core technologies — like electro-spraying, extrusion, vapor deposition, melt spinning, and melt spraying — all with their own pros and cons.

  • Electro-spraying is additive manufacturing applied to the charged metals space, wherein charged powders are sprayed to a substrate of the opposite charge. This provides high speed, uniformity, flexibility, and layering capabilities, but with drawbacks of requiring dry mixing and heated-pressing considerations.
  • Extrusion is a viable option, wherein a cathode paste and divider substrate are mechanically extruded into form and shape at high speed and high uniformity — however, this is limited to the cathode and also requires heated pressing to finalize.
  • Vapor deposition is unique in vaporizing an active material and (within a vacuum) depositing said material on a substrate. This provides angstrom-precise thickness control, however, it requires excess energy and is slow with scalability, both of which are of huge concern.
  • Melt spinning melts a layer of the material of interest into a spinning drum, where centrifugal force creates a consistent layer and will separate multiple layers based on density, if more than one material is introduced. However, this can quickly get complicated and intractable, when too dissimilar materials are involved and require excessive energy for operations, particularly at scale.
  • Melt spraying is spraying a material on a heated substrate to which it will melt and bind, which has similar restrictions to spinning and remains relatively unexplored.

Of these techniques, AM Batteries (AMB) and their novel electro-spray approach showed the most promises based on both technical and market viability analysis. Their method includes a dry spray of electrically charged cathode particles which are attracted to the oppositely charged base foil. The electrically bound mixture is then mechanically pressed and bound into place via hot roller and the result is a layer of consistent and controllable thickness — all with no wet slurry necessary and a calculated potential for more than 57% reduction in energy required.

Two of their founders, Profs. Yan Wang and Heng Pan, are internationally recognized experts in dry-mixing, coating, and pressing within the field of battery manufacture. Leveraging this experience, AMB developed their process to come out even or better in most critical performance parameters, when compared to the current wet-slurry standard, and more so done in such a way that the method can be readily implemented into current manufacturing lines. This drastically decreases necessary time to transition the technology for use in mass production and distinguishes the technology as ripe for venture-style returns.

To ensure diligence, we vetted AMB’s approach against other technologies through comparison of performance parameters and characteristics including: binder type, binder cost, anode feasibility, mixing/coating energy consumption, coating speed, electrode thickness capability, and more including an overall evaluation of technical maturity to evaluate readiness for implementation. In all cases, we felt that AMB proved to be just as good, better, or demonstrated potential to perform better across the board compared to state-of-the-art “wet coating” methods. Based on our independent review of cell-makers and potential customers (in the EV and consumer batteries market), providing the context previously discussed here, it was immediately apparent how relevant and pervasive a solution such as this could be throughout the battery industry.

Moving forward, AMB is addressing concerns for mass production head-on. Over the next 18 months, they are looking to develop a pilot coater to demonstrate to customers in practice how they can bridge that gap from lab to near-manufacturing scale in an effort to mitigate manufacturability risk. This is where we, as a corporate venture fund, can leverage our mothership TDK Corporation’s expertise to help AMB. TDK’s engineers are pioneers in materials science, process engineering, and mass manufacturing in the LiB industry. We are ever thankful for our TDK engineers and we hope that AMB’s team can leverage our “TDK Goodness” throughout their technology development and deployment journey.

TDK Ventures’ mission is to deliver meaningful financial results while exploring strategically relevant technologies to bring positive change to society and the environment. We believe AMB can be a pivotal building block towards positive change on the road toward sustainable energy transition, and we hope to use our mission and vision to ensure AMB can be a key player along the way.

References

1 Source — The History of the Electric Car. (Sept 2014). Retrieved from https://www.energy.gov/articles/history-electric-ca

2 Ahmed, Shabbir, Paul A. Nelson, Kevin G. Gallagher, and Dennis W. Dees. “Energy impact of cathode drying and solvent recovery during lithium-ion battery manufacturing.” Journal of Power Sources 322 (2016): 169–178.

3 https://thedriven.io/2021/07/22/tesla-sells-maxwell-technologies-but-keeps-dry-cell-tech/

4 Elon Musk quoted — Battery Days, Sept 2020

Please also view TDK Ventures latest announcement:

TDK Ventures invests in seed round for dry lithium-ion electrode manufacturing startup, AM Batteries

About the author:

Anil Achyuta is an investment director and founding member of TDK Ventures ($200M AUM) that invests globally in early-stage startups that leverage fundamental material science to unlock an attractive and sustainable future for the world. It is a wholly-owned subsidiary of TDK Corporation, a world leader in electronic solutions for the smart-products universe. Anil is passionate about the energy and healthcare sectors, as he believes these are the most impactful areas in building a sustainable future, a mission that is directly in line with TDK Ventures’ goals. At TDK Ventures, he has reviewed over 1500 start-ups and invested in nine companies: 1) Autoflight — an electric vertical take-off and landing company; 2) Genetesis — a magnetic imaging-based cardiac diagnostics company (Board Member); 3) Origin — a 3-D printing mass-manufacturing company; 4) Exo — a hand-held 3-D ultrasound imaging company; 5) GenCell — an ammonia-to-energy hydrogen fuel-cell company; 6) Mojo Vision — an augmented-reality contact-lens company, 7) Battery Resourcers — a direct-to-cathode lithium-ion battery recycling company (Board Observer), and 8) Fabric8 Labs — an electrochemical deposition metal 3D printing company (Board Observer), and 9) AM Batteries — a dry-electrode-based lithium-ion battery manufacturing company. Of his nine investments, Anil has secured two exits: GenCell IPO’d on the Tel Aviv Stock Exchange (GNCL:IT), and Origin, which was acquired by the #1 3-D printing company in the world, Stratasys, for $100M.

Anil was voted one of the Rising Stars in 2021 by Venture Capital Journal and was ranked #2 Rising Star in 2021 out of 20,000 corporate venture managers globally. Prior to TDK Ventures, Anil held leadership roles at Fortune 500 companies including L’Oréal, Johnson & Johnson, GlaxoSmithKline, and Draper. He has a Ph.D. in Chemical Engineering from Northeastern University and received his MBA from the University of Florida — Warrington College of Business. He has authored over 15 peer-reviewed journal publications and holds five U.S. patents.

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