Batteries used in electric vehicles and stationary storage applications are vital to a clean energy future. However, the electrodes for these batteries are typically made using a wet process, which is plagued by various challenges, including environmental impacts and costly manufacturing steps. 

In a conventional wet electrode process, the cathode and anode active materials are mixed with binders in a wet solvent to form a slurry. This slurry is then coated onto a metal foil and heated at high temperatures to evaporate the solvent, before progressing to cell assembly.

Usually, this conventional process relies on toxic N-Methylpyrrolidone (NMP) solvents, which can be harmful to humans, says Hieu Duong, chief manufacturing officer (cmo) at AM Batteries. “The constant handling of toxic, carcinogenic NMP poses significant health risks for battery plant employees and demands sophisticated ventilation and disposal protocols that add complexity and cost,” he tells Kallanish.

Moreover, the slurry requires extensive, energy-intensive drying – which needs massive infrastructure spanning areas as large as football fields. This alone accounts for around 50% of a battery plant’s energy consumption and 30% of manufacturing costs, the executive highlights.

“Typically, in these gigafactories, you see these enormously long drying ovens that can accommodate a very rapid speed of electrode production, but the speed of evaporation is so slow that these drying ovens need to be extremely long,” adds Denis Phares, president and ceo of Dragonfly Energy. “You’re imparting a large amount of energy over a large amount of space, and therefore, you have a very large carbon dioxide footprint. It’s the most energy-intensive part of the process, and therefore not very environmentally benign from a climate change standpoint, and is very ripe for an advancement.”

Duong, former Tesla director of dry electrode manufacturing, agrees: “As battery makers race to scale production to create a more electrified world, the industry urgently needs to break free from these decades-old manufacturing constraints that have prevented transformative improvements in both environmental impact and production efficiency.”

Consequently, in recent years, industry giants and newcomers alike have been betting big on an alternative that promises to cut costs and energy use: dry electrode manufacturing.

Dry electrode manufacturing’s appeal

In dry electrode manufacturing, active materials and binders are deposited directly onto metal foils in a dry state, eliminating the need for toxic solvents. This avoids the need for complex multi-step methods, including the time- and energy-intensive solvent evaporation step.

“Beyond dramatic energy efficiency improvements, dry electrode manufacturing enables next-generation battery technologies like solid-state batteries that simply cannot be produced using traditional wet methods,” Duong points out. “By removing this critical barrier to innovation, the technology makes advanced battery chemistries commercially viable at scale – transforming what’s possible in energy storage while simultaneously improving economics and environmental impact.”

In 2020, Tesla announced plans to manufacture its 4680 cells using the dry electrode process, which, the automaker then said, could reduce the energy consumption of overall cell manufacturing by over 70%. This came on the heels of Tesla acquiring energy storage company Maxwell Technologies, which focuses on dry electrode technology, in 2019.

In July last year, Tesla commenced the vehicle testing of the first prototype Cybertruck produced with the in-house dry cathode 4680 cells. Once ramped up, the carmaker expects a “major cost reduction milestone” from the technology. In October, the company said it “continued to progress” its dry cathode manufacturing lines without elaborating.

Last September, Samsung SDI started pilot production pilot of dry electrodes at its Cheonan plant in South Korea. Its compatriot LG Energy Solution is targeting to achieve mass production in 2028.

In the US, Massachusetts-based AM Batteries claims to be “revolutionising” battery manufacturing with its proprietary Powder-To-Electrode method. The three-step process starts by combining active materials with conductive additives and binders into an engineered composite powder – a step Duong says takes minutes instead of hours. Then, the powder is precisely sprayed onto a charged metal foil, followed by a hot calendering process to bind the powder layer to the current collector.

The technology, he claims, can offer 30% lower capital costs, 75% less energy consumption, and a 5x smaller factory footprint compared to traditional wet coating methods. It is compatible with commercially available materials across diverse chemistries, “making it practical to scale and integrate into existing supply chains.”

“Our process stands apart from other dry electrode manufacturing techniques by requiring just a single deposition step, eliminating the separate electrode film creation, lamination, or complex extrusion processes demanded by competitors,” Duong adds. “Our approach is completely solvent-free, unlike other methods that still rely on solvent mixing and spray drying to create composite particles.”

Nevada-based battery manufacturer Dragonfly is also developing a patented dry electrode manufacturing process. The dry deposition method involves spray drying the electrode materials, before applying them using a powder coating spray onto an electrostatically charged foil that moves through rollers. This patented technique enables coating both sides of the foil simultaneously, speeding up the process. 

“This results in a highly uniform electrode application with strong adhesion, producing high-quality cells at a lower cost while also enhancing scalability,” explains Tyler Bourns, chief marketing officer at Dragonfly. “It also opens the door to new innovations such as PFAS-free electrodes and non-flammable all-solid-state battery cells.”

A third-party assessment last year suggested the process offers a 9% reduction in carbon footprint for total cell manufacturing, a 22% smaller manufacturing footprint, and 25% less energy-intensive production. This process too is polymer and chemistry agnostic. 

“If you’re looking at a completely IRA-compliant supply chain with manufacturing in the United States, compared to the equivalent film manufactured in China, with an Asian supply chain, we actually come out cheaper than that,” ceo Phares claims in an interview.

Yet, scaling up the technology comes with challenges.

Phares points out that scaling up a new technology comes with engineering issues that need to be solved. For dry electrodes, the biggest challenge that has come up in previous attempts is around yield. However, he claims Dragonfly’s process solves “a lot of these yield issues” due to their lower-cost equipment and strong adhesion.

Sungrok Bang, executive vice president at South Korea-based SNE Research, says one of the main challenges is achieving consistent electrode performance, particularly in maintaining uniformity across large-scale production. 

“Variations in electrode density and adhesion can impact battery performance,” Bang explains. “To overcome these issues, companies are focusing on refining material formulations, optimising manufacturing parameters, and improving process control.”

For AM Batteries, the main bottleneck is production speed. The start-up is focusing on developing higher-speed capabilities for mass production while maintaining the technology’s precision and uniformity advantages. “Rather than compromising quality for speed, we’re advancing both simultaneously through targeted engineering innovations,” Duong notes.

What’s next?

Dragonfly is capital-constrained, and looking to raise funds to build a half-gigawatt-hour scale facility – something Phares hopes to complete over the next couple of years. A Canadian subsidiary of the company is in advanced discussions with a Canadian province to provide some capex support.

“Dragonfly Energy is in a very, very strong intellectual property position in the dry electrode space,” he claims. “We were very early to the game. There are others in this space, but I think we have the strongest intellectual property position given when we started. On top of that, we’re unique in that we are an already revenue-driving battery pack business.”

Even without a timeframe for mass production, AM Batteries has managed to convert investor interest into funding. It has raised over $74 million from the likes of Toyota Ventures, Porsche Ventures, and TDK Ventures.

The trend is set to pick up pace, as dry electrode technology is expected to become mainstream over the next decade “as manufacturers resolve performance challenges and enhance process efficiency,” concludes Bang. “Its importance lies in its ability to address moisture sensitivity issues, reduce production costs, and enable more sustainable and scalable battery manufacturing, making it a crucial advancement for the global battery industry.”