Dr Thomasina Ball

Thomasina Ball

Assistant Professor

Office: C2.09
Phone: +44 (0)24 765 24406
Email: Thomasina.Ball (at) warwick.ac.uk

Teaching Responsibilities 2025/26:

Term 2: MA269 Asymptotics and Integral Transforms

Research Interests:

My research interests lie in mathematical modelling of fluid dynamical phenomena from observations of laboratory experiments and the natural world around us. In particular I am interested in the areas of: non-Newtonian rheologies, yield stress fluids, gravity-driven flow, geophysical flows, instabilities that arise from rheology contrasts, fluid-structure interactions.

Please contact me about potential R-project, MSc, URSS project or PhD supervision.

See my Research Interests page for more information.

Opportunities:

PhD on "Modelling non-Newtonian thin films for battery electrode coating" [home students only]

Supervisors: Ferran Brosa Planella & Thomasina Ball

Industrial Supervisor: Helen Walker (UKBIC)

Deadline: 15^th of May

Project summary

Coating is a key process in battery manufacturing. Due to the cost of the manufacturing process, it is essential to coat as fast as possible while avoiding defects both at the slot die and further downstream. It is well known that the slurry used in the coating process is non-Newtonian. This might include a nonlinear viscosity or a yield stress, distinguishing solid- and fluid-like behaviour. There are also new coating methods being introduced that have not been extensively researched. For example, multi-layer slot die coating has the potential to improve the performance of the battery electrodes. But our understanding of how the coupled layers compete to create a stable film is poorly understood.

Project aims

In this PhD project we aim to understand the influence of rheology of the coatings and how multiple layers effect the system. The focus will be on reduced-order modelling to understand the key physical processes at play. The PhD student will begin by building a thin film model coupling two layers with surface tension effects, van der Waals forcing, and non-Newtonian viscosities. The coupled system will then be explored analytically and numerically to understand the stability of the fluid interfaces downstream of the slot die.

Project outcomes

The main project output will be a set of guidelines on operating conditions and detailed stability windows, with a focus on the influence of rheology and how the multiple layers interact. The model development will be complemented by experimental data from industry partner UKBIC.

What we're looking for

The project will involve mathematical modelling of physical processes and numerical implementation to go beyond analytical results. We are looking for a student with a strong background in mathematics, physics or engineering who is enthusiastic about mathematical modelling in fluid dynamics with applications to the battery industry.

Eligibility and stipend

This PhD is open to home students only (UK nationals or those with settled status). Check if you are eligible here.

How to apply?

Apply through the Warwick Maths CDT. Instead of writing a full research proposal, please just state you want to pursue the “Modelling non-Newtonian thin films for battery electrode coating” project.

For informal enquiries, please email Ferran Brosa Planella.

Equality, Diversity and Inclusion

Equality, diversity and inclusion concerns every member of our community. The Mathematics Institute provides an inclusive working and learning environment, recognising and respecting all individuals' differences. For more information, please see the department’s Equality, Diversity & Inclusion page.

References

Kasischke, S. Hartmann, K. Niermann, M. Smarra, D. Kostyrin, U. Thiele, E.L. Gurevich, Pattern formation in slot-die coating, Physics of Fluids 35 (2023) 074117. https://doi.org/10.1063/5.0150340 (numerical study looking at stability of Newtonian thin films)
D. Reynolds, S.D. Hare, P.R. Slater, M.J.H. Simmons, E. Kendrick, Rheology and Structure of Lithium-Ion Battery Electrode Slurries, Energy Technology 10 (2022) 2200545. https://doi.org/10.1002/ente.202200545 (discussion of the slurry rheology and it’s impacts on coatings)
Hoffmann, J. Klemens, S. Raupp, C. Hanske, N. Lawrenz, M. Machate, P. Scharfer, W. Schabel, Optimized battery electrodes with primer layers by simultaneous two-layer slot-die coating, Eur. Phys. J. Spec. Top. 234 (2025) 3065–3076. https://doi.org/10.1140/epjs/s11734-024-01398-7 (description of multilayer slot die coatings)

Most relevant recent publications:

Ball, T. V. & Balmforth, N. J. (2025) Non-axisymmetric patterns in floating viscoplastic films. J. Fluid Mech. 1007.
Ribinskas, E., Ball, T. V., Penney, C. E., & Neufeld, J. A. (2024) Scraping of a viscoplastic fluid to model mountain building. J. Fluid Mech.

See my Publications page for a full list with preprints.

Recent and upcoming conferences/seminars:

European Fluid Dynamics Conference (Aug. 2025)
VPF10 Viscoplastic Flows, Amsterdam (July 2025)
Applied Maths Seminar, University of Nottingham (May 2025)
University of Oslo Mechanics Seminar Series (Mar. 2025)
Applied and Industrial Mathematics Seminar (AIMS), Bath University (Jan. 2025)
APS DFD, Salt Lake City (Nov. 2024)
Fluids and Structures Seminar, UEA (Nov. 2024)
Physical and Applied Mathematics Seminar, Manchester (Oct. 2024)
European Fluid Dynamics Conference (Aug. 2024)
BAMC, Newcastle University (April 2024)
Workshop on Mathematical modelling for environmental challenges (March 2024)
Fluids and MHD Seminar, University of Leeds (Nov. 2023)
APS DFD, Washington DC (Nov. 2023)
8th Pacific Rim Conference on Rheology (May 2023)
MACSI Seminar, University of Limerick (March 2023)
Fluids Seminar, Imperial College London (March 2023)
Fluids and materials seminar, University of Bristol (Sept. 2022)
European Fluids Mechanics Conference, Athens, Greece (Sept. 2022)

Recent research grants:

Leverhulme Early Career Fellowship ECF-2022-584 Buckling instabilities in geophysical flows 09/2022-09/2025 (Newsletter September 2022)

Recent awards & prizes:

Journal of Non-Newtonian Fluid Mechanics (JNNFM) Walters Award 2021: Thomasina Ball, Neil Balmforth and Ariel Dufresne. Viscoplastic fingers and fractures in a Hele-Shaw cell, J. Non-Newton. Fluid Mech., vol. 289, 104492 (2021) (link)
APS Division of Fluid Dynamics François Frenkiel Award for Fluid Mechanics 2018: Thomasina Ball and Jerome Neufeld. Static and Dynamic Fluid Driven Fracturing of Adhered Elastica, Phys. Rev. Fluids 3, 074101 (2018) (link)