Air bubbles introduced during slurry mixing and delivery can create defects in coated electrodes, ultimately compromising battery performance, reliability, and safety. In response, UKBIC, the UK’s national manufacturing development facility, has delivered a programme of research and engineering development to understand, mitigate, and prevent air entrainment at every stage of the manufacturing process.

The new paper outlines the methodologies, models, and equipment improvements implemented by UKBIC’s in house technical teams to address this issue.

The work spans process optimisation, formulation refinement, and equipment redesign, thereby demonstrating that defect prevention requires an integrated approach across technology teams.

A systems-level approach to defect reduction

The research combines physics-based modelling with experimental validation to better understand the mechanisms of degassing and bubble behaviour. This included:

• Developing advanced models to predict degassing performance under different viscosity, density, and vessel geometry conditions.
• Implementing targeted design improvements to slurry delivery systems to reduce air ingress points and minimise opportunities for air entrainment.
• Refining coating parameters to ensure bead stability during slot die coating, supported by CFD and analytical modelling to define robust operating windows.
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Key findings

The paper highlights several important insights for battery manufacturers:

• Air entrainment is a critical manufacturing challenge, strongly influencing coating quality, electrochemical performance, and long-term cell reliability.
• Understanding degassing behaviour is essential: while vacuum degassing accelerates bubble removal, its effectiveness depends on material properties and vessel design.
• Formulation and mixing strategies matter: optimising solids content, additives, and mixing processes can significantly reduce viscosity and shorten degas times.
• Equipment design is a major contributor: agitator geometry and slurry delivery system complexity have a strong impact on air ingress and degassing efficiency.
• Inline deaeration and improved mixing protocols offer promising opportunities for future gains.
• Coating stability acts as a final safeguard: precise control of bead stability is vital to prevent air entrainment at the coating stage.
• Effective defect mitigation improves product yield and reliability, reducing defects and enabling more uniform coatings, a higher energy density, and longer cycle life.

Advancing UK battery manufacturing capability

Dr Helen Walker, UKBIC Senior Simulation Engineer and co-author of the report, said: “The findings demonstrate UKBIC’s commitment to strengthening the UK’s battery manufacturing competitiveness through process insight, practical engineering solutions, and collaborative R&D. The centre’s work provides manufacturers with clearer tools, models, and best practices to reduce defects, improve yields, and produce higher performance electrodes at scale.”

To download the new white paper Optimising Electrode Quality: Controlling Air in Battery Slurries for Superior Coating Performance and to listen to a recording of the webinar given by Dr Helen Walker, visit this page.

About the author

Dr Helen Walker is a senior process simulation engineer at UKBIC. She develops Multiphysics simulations and other modelling tools to advance process understanding, improve product quality and reduce wasted time and materials on the production line. Particular areas of model development include slurry degassing, coating, drying and calendering. Helen has 7 years of experience in manufacturing research working across industries such as aerospace and renewable energy, developing Multiphysics simulations to improve product performance and inform process design. She holds a PhD in Mathematics from The University of Nottingham.

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Notes to Editors
To arrange an interview or to request photography please email richard.robinson@ukbic.co.uk or phone +44 (0) 7503 628892

UKBIC is the UK’s national manufacturing development facility, providing scale-up, laboratory expertise, and module and pack assembly, and helping develop skills to support the sector. 

By bridging the gap between research and high-volume manufacturing, UKBIC plays a critical role in supporting the UK’s transition to net zero and strengthening its position in the global battery supply chain.

UKBIC provides state-of-the-art equipment, technical expertise, and training to help manufacturers and researchers validate processes, optimise performance, and reduce risk before committing to large-scale investment.

The facility offers both pilot and industrial-scale lines, enabling customers to trial new materials and processes under real-world conditions.

UKBIC also supplies its own benchmark products for component testing and delivers specialist training to develop the skills required for a battery-powered future. 

UKBIC is uniquely positioned to tackle complex manufacturing challenges. With expertise in processing diverse materials and products, and access to a broad range of advanced technologies, its engineers bring a comprehensive understanding of issues that span the entire battery value chain.

UKBIC is part of The Battery Innovation Programme, a flagship of the UK Industrial Strategy, funded by the Department for Business and Trade and delivered by Innovate UK.