Supervisors: Dr. Ferran Brosa Planella (Maths), Dr. Radu Cimpeanu (Maths), Prof. Louis Piper (WMG)

Summary:

Manufacturing not only has a significant impact on battery performance and lifetime, but also on cost and environmental impact. A key process (yet not a well-studied one) is the so-called filling, in which a liquid electrolyte is incorporated into the battery, occupying the pores in the electrodes. It requires keeping the battery at high temperatures for days, becoming a very expensive process both in terms of time and energy usage. In this project, you will have the opportunity to build exciting new capabilities for modelling and optimisation of electrode filling, with a potential to energise our understanding of battery manufacturing.

Background:

Manufacturing not only has a significant impact on battery performance and lifetime, but also on its cost and environmental impact. A key process (yet not a well-studied one) is the electrolyte filling, in which the liquid electrolyte is incorporated to the battery and let to fill the pores in the electrodes [1]. This process requires keeping the battery at high temperatures for several days, becoming a very expensive step in battery manufacturing (both in terms of energy and time). In addition, if the electrodes are not fully wetted, the performance of the battery diminishes drastically. Understanding and optimising electrode wetting is key to improve battery performance and reduce the manufacturing cost, but this has mainly been addressed from the experimental side [2].

Fig 1. Experimental setup to study electrode wetting (reproduced from [2]).

Fig 2. Real experimental setup for the filling of a pouch cell battery (from Prof. Piper’s group).

Project Objectives for the PhD project:

The focus of this project is on developing new models for electrode wetting, which can be used to understand and optimise this manufacturing process. We will start with standard models for flow in porous media and adapt them to the particularities of electrode wetting. Such models can later be extended to describe more complex phenomena, such as solvent penetration during the recycling process, or gas formation and metal dissolution during the battery operation.

For the success of this project, a combination of analytical (e.g. asymptotic analysis) and numerical approaches (e.g. finite volume methods) will be required to implement and validate the wetting models. It will be fundamental to deploy the implementations of the models so other researchers and industry can use them, thus the models will be built upon established packages such as PyBaMM [3] and Basilisk [4]. Along with the models, parameterisation tools will be developed and will incorporate uncertainty quantification, which is necessary given the stochasticity of the porous electrode materials.

Relevant references:

[1] E. Kendrick, Advancements in Manufacturing, in: Future Lithium-Ion Batteries, 2019: pp. 262–289. https://doi.org/10.1039/9781788016124-00262.

[2] A. Davoodabadi, J. Li, Y. Liang, D.L. Wood, T.J. Singler, C. Jin, Analysis of electrolyte imbibition through lithium-ion battery electrodes, Journal of Power Sources. 424 (2019) 193–203. https://doi.org/10.1016/j.jpowsour.2019.03.115.

[3] PyBaMM, https://www.pybamm.org (accessed 12/01/2024).

[4] Basilisk, https://www.basilisk.fr (accessed 12/01/2024).