Patricia Hubbard is the Senior Vice President and Chief Technology Officer for Cabot Corporation, having joined the company in 2018. In this role, Patricia is responsible for developing the strategic technical agenda within the company, driving corporate and business-focused research and development, and developing the enabling innovation capabilities to ensure long-term growth.
Prior to joining Cabot, Patricia worked for Avery Dennison as Vice President of R&D for the Label and Graphic Materials division in North America, and has held leadership positions at PolyOne Corporation, General Electric (now Momentive and SABIC), and ICI Paints (now PPG). Throughout her career, she has garnered extensive knowledge of materials science and formulated solutions that have driven new product development and technology innovation.
Patricia earned a BS in chemistry from Case Western Reserve University, a Ph.D. in polymer science from the University of Akronand is a certified Lean Six Sigma Black Belt. She has served on non-profit boards of the Old Stone Education Center in Cleveland, OH, and the Boys & Girls Clubs of Lorain County. She currently serves on the technology advisory board for the Texas State University Department of Chemistry and Biochemistry and the board of directors for NAATBatt International, and in 2022, was appointed to the National Academies’ Chemical Sciences Roundtable. She is a volunteer mentor with American Corporate Partners.
"Solvent-Free Cathode Processing Enabled by Multi-FunctionalConductive Carbons"
Conductive carbons are ubiquitous in lithium ion battery cathodes, and play a critical role in enabling higher power, higher energy density, faster charge, and improved safety. The primary carbons in use today are conductive carbon blacks, multiwalled carbon nanotubes, and blends that are designed to optimize performance for a specific cell design. Even with the low addition levels used in cathodes - less than 3% in LFP-based systems and in NCx systems, less than 2% - their presence both facilitates the short-range transfer of lithium into the cathode active materials, as well as improves the long-range electrical conductivity to the current collector.
Cathodes for lithium ion batteries are manufactured today primarily by a traditional coating process from a slurry inN-methyl-2-pyrrolidone (NMP) solvent. The slurry is comprised of the cathode active material, binder, conductive carbon, and very low levels of dispersants designed to maintain a stable slurry in NMP with appropriate coating rheology. While NMP has outstanding characteristics as a polymer solvent, its use is increasingly challenged due to the costs of recycling the NMP during the electrode drying process as well as the restrictions being imposed due to its health concerns.
One promising alternative to NMP-based electrode processing is solvent-free, dry processing. The elimination of NMP solvent promises both cost and environmental benefits, but brings new challenges in achieving good dispersion, low electrode resistivity and suitable mechanical integrity. State-of-the-art dry processing formulations include additives designed to help the polymeric binder fibrillize so that even fair mechanical integrity can be achieved. This addition - typically at a few percent of the formulation - has the unfortunate side effect of lowering the cathode active loading that can be achieved, and thus the energy density.
Our research has focused on enabling both polymer fibrillization and electrical conductivity with the same additive, and in delivering performance with a lower total additive level in the cathode to maintain the highest possible energy density in the cell. In this talk, we will share our most recent results in NMC-based cathode systems in laboratory testing, as well as the path to commercial scale viability.