A comprehensive review of the state of the art for battery electrode processing informs researchers, battery manufacturers and other industry stakeholders on key technical barriers that need to be addressed to accelerate commercialization.
Numerous market analyses have shown that over the next five years, demand for lithium-ion batteries for everything from personal electric devices to grid-scale energy storage is expected to grow dramatically. To meet this demand, battery manufacturing needs to be faster, cheaper, more dependable, less energy-intensive and less wasteful. A key part of lithium-ion battery manufacturing with significant room for improvement is the processing and fabrication of electrodes.
To facilitate advances in this area, researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have conducted a comprehensive review of the scientific literature on advanced electrode processing technologies. The Argonne team collaborated with the DOE’s Oak Ridge National Laboratory (ORNL) and Case Western Reserve University (CWRU) researchers on the effort.
The review outlines recent developments, advantages and disadvantages with four categories of technologies. It also delves into their engineering, operations and instrumentation. Finally, it offers a perspective on future technology trends.
The review doesn’t endorse any particular technology but rather informs the battery industry and research community on key technical barriers that need to be addressed to accelerate commercialization.
“These advanced technologies show great promise to reduce manufacturing costs, which can help lower the prices of grid energy storage and batteries for mobility applications,” said Runming Tao, Argonne postdoctoral appointee and the review’s lead author. ?“Our study provides a complete, objective view of the state of the art for battery electrode processing.”
Tao and co-authors Zhijia Du (former ORNL staff scientist and now the director of battery development at Safire) and Jianlin Li (Argonne’s energy storage and conversion program manager) are leading experts in the field. Over the last decade, they have published numerous technical papers on the electrochemistry and material science aspects of electrode processing.
The Llimitations of Conventional Electrode Processing
Conventional wet electrode processing involves mixing a conductive material, an electrochemically active material and a binding agent in a solvent to form a slurry. The slurry is then cast onto a metal foil substrate and heat-dried in an oven. The drying process removes the solvent and forms a solid electrode. Finally, a calendering machine uses rollers to compress the electrode into its final form. Ultimately, the electrode is assembled in a battery.
A major shortcoming of wet processing is its reliance on a toxic organic solvent called N-methylpyrrolidone (NMP). The drying process that removes the solvent is very energy-intensive, adding significant cost. To minimize environmental impacts, the solvent needs to be recovered, requiring additional equipment and operational costs. Eliminating the use of NMP can significantly reduce energy and material costs as well as the footprint of manufacturing equipment.
Advanced Technologies Offer Various Advantages Over a Traditional Approach
The review covered four categories of advanced processing technologies:
- Advanced wet processing uses similar equipment to conventional wet processing. By using water instead of NMP as the solvent, this method can reduce energy costs by 25%. Research has shown that it can produce uniform electrodes with good performance. However, it still requires energy-intensive oven-based drying. Also, certain battery materials may need changes to improve their compatibility with water.
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With radiation curing, ultraviolet light or electron beams are applied to slurries made of small precursor molecules. The radiation causes the molecules to link together into polymers (large molecules with repeating chemical units).
This approach can significantly reduce and potentially eliminate the use of solvents and ovens. As a result, it is much faster than conventional wet processing, can reduce energy costs by as much as 65% and requires 85% less factory floor space. However, more research is needed to assess the polymers’ stability and compatibility with other battery components.
The ultraviolet approach can only make thin electrodes. Thicker electrodes would require curing several layers individually. This could adversely impact battery performance. The electron beam approach would require more expensive equipment and the development of new occupational safety procedures.
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With dry processing, a mixed powder is passed through rollers to form a solid electrode film. By eliminating the need for solvents and energy-intensive drying, this method can reduce manufacturing costs by 11% and energy use by 46% relative to conventional wet processing. A key technical challenge is the binder’s limited stability in carbon-based negative electrodes and low electronic conductivity.
“These challenges could be addressed with research on materials with different particle sizes, shapes and structures,” said Tao. ?“Another important research need is equipment modifications to improve how dry powders are mixed before being compressed.”
- 3D printing uses techniques such as direct ink writing and material jetting to fabricate electrodes. The main advantage of the approach is its ability to produce customized, precise electrode shapes and designs with minimal waste. This potentially makes it a good option for high-value batteries used for niche applications. The downsides of 3D printing are slow manufacturing speed and expensive printing equipment.
All of these technologies show promise for commercialization. ?“Different companies may have different preferences on these advanced processing technologies depending on the particular battery applications they are focused on,” said Li.
According to Li, dry processing has the fewest remaining technical barriers and appears to be the closest to large-scale commercialization. In fact, for several years, multiple leading companies have been investigating the use of dry processing for battery cells.
The paper was published in the February 3, 2025 edition of Nature Reviews Clean Technology. Besides Tao, Du, and Li, the other authors are Yu Gu (CWRU) and Xiang Lyu (ORNL).
This research was made possible with support from DOE’s Advanced Materials and Manufacturing Technologies Office and Vehicle Technologies Office within DOE’s Office of Energy Efficiency and Renewable Energy, as well as the National Science Foundation.