Research Studentship in Multiphysics Modelling of Solid-State Batteries

3.5-year D.Phil. studentship

Project: Modelling electro-chemo-mechanical couplings in Solid-State Batteries

Supervisors: Prof Laurence Brassart and Prof Charles Monroe

Solid-state batteries (SSBs) are viewed as a promising successor to Li-ion batteries, offering higher energy density, faster charging, and improved safety. In SSBs, cathodes present a composite microstructure, consisting of cathode particles, a solid electrolyte, and conductive phases. Compared to conventional Li-ion batteries, the use of a solid, non-flammable electrolyte provides both safer operation and mechanical stability. However, it also introduces intrinsic couplings between ionic transport, driven by electro-chemical fields, and mechanical stresses. For example, cyclic insertion/extraction of ions causes volumetric expansion/contraction of the host solid, which can lead to interfacial decohesion and cracking. Conversely, local stresses can impact the diffusion rate. To design reliable SSBs, a precise understanding of electro-chemo-mechanical couplings in composite cathodes is needed, along with predictive computational tools.

This DPhil project aims to develop a multiphysics continuum model to describe ionic transport coupled to mechanics in composite cathodes. The model will be formulated within the framework of irreversible thermodynamics, enabling a rigorous description of the various couplings. The model will be used to simulate charge and discharge of representative cathode microstructures, and to establish relationships between material properties, microstructure, and the overall battery performance. Several specific areas of focus could be explored during the project, depending on the candidate’s interests:

• The description of loss of electroneutrality in the solid electrolyte, which can result in huge stress concentrations, driving failure phenomena such as dendrite growth and voiding, but has been largely neglected in existing models;
• The numerical simulation of failure phenomena, such as interfacial debonding, cracking or dendrite growth, and identification of design strategies to mitigate them;
• The development of a coupled diffusion-mechanics homogenisation model enabling battery-scale simulations at low computational cost.

This DPhil is part of the SOLBAT project of the Faraday Institution, which aims to demonstrate the feasibility of SSBs with performance superior to Li-ion batteries for electric vehicles applications. Experimental data supporting model development will be provided by our collaborators in the Department of Materials Science via SOLBAT. The project is suited for a candidate with an appetite for theoretical and/ or computational work.

Eligibility

This studentship is funded through the Department of Engineering Science and is open to Home students (full award – home fees plus stipend). 

Award Value

Course fees are covered at the level set for Home students c. £10,470 p.a. The stipend (tax-free maintenance grant) is c. £21,805 p.a. for the first year, and at least this amount for a further two and a half years.

Candidate Requirements

Prospective candidates will be judged according to how well they meet the following criteria:

• A first class or strong upper second-class undergraduate degree with honours (or equivalent) in Engineering, Physics, Mathematics, or Materials Science
• Excellent English written and spoken communication skills 
• Foundations in Continuum Mechanics and Thermodynamics 
• Ability to program in Matlab or Python 

The following skills are desirable but not essential:

• Experience in numerical methods (e.g. finite elements)

Application Procedure

Informal enquiries are encouraged and should be addressed to Prof Brassart (laurence.brassart@eng.ox.ac.uk).

Candidates must submit a graduate application form and are expected to meet the graduate admissions criteria. Details are available on the course page of the University website.

Please quote 26ENGMM_LB in all correspondence and in your graduate application.

Application deadline: noon on 3 March 2026 (In line with the University admissions deadline set by the University)

Start date: October 2026