Optimisation of metal-air batteries
This work involves a complementary experimental and mathematical modelling approach to provide decision support capabilities for the understanding and subsequent optimisation of lithium-air electrodes for secondary batteries.
Modelling ion transport through nanopores
The study of transport of ionic species through a nanopore is important in determining the underlying behavior of electrolytes on the nanoscale; the understanding of which has important applications in the development of biomolecular sensors and nanofluidic diodes. In this project we develop a consistent framework that couples the Poisson-Nernst-Planck equations with Butler-Volmer kinetics at the electrode/electrolyte interface to model ion transport through a nanopore. We are able to perform quantitative comparisons between simulated current-voltage curves and those obtained experimentally.
Modelling of Lithium Metal Phosphate Batteries
This project is looking at the development and numerical solution of mutliscale, high-dimensional, Cahn-Hilliard Reaction models to predict the phase change behaviour within secondary, lithium-ion batteries. Such model systems are notoriously difficult to solve accurately and novel numerical approaches have been developed to achieve this.
Multicomponent charge transport
This work investigates the mathematical modelling of charge transport in electrolyte solutions, within the nanoporous structures of electrochemical devices. We compare two approaches found in the literature, by developing transport models based on the Nernst-Planck and Maxwell-Stefan equations.
The development of the Nernst-Planck equations relies on the assumption that the solution is infinitely dilute. However, this is typically not the case for the electrolyte solutions found within electrochemical devices. Furthermore, ionic concentrations much higher than those of the bulk concentrations can be obtained near the electrode/electrolyte interfaces due to the development of an electric double layer. Hence, multicomponent interactions which are neglected by the Nernst-Planck equations may become important. The Maxwell-Stefan equations account for these multicomponent interactions, and thus they should provide a more accurate representation of transport in electrolyte solutions. To allow for the effects of the electric double layer in both the Nernst-Planck and Maxwell-Stefan equations, we do not assume local electroneutrality in the solution. Instead, we model the electrostatic potential as a continuously varying function, by way of Poisson’s equation. Importantly, we have shown that for a ternary electrolyte solution at high interfacial concentrations, the Maxwell-Stefan equations predict behaviour that is not recovered from the Nernst-Planck equations.
Chief Investigators
Publications
- Conway, Eamon, Farrell, Troy, Psaltis, Steven (2018) Mathematical modeling of ion transport through nanopores. Journal of Physical Chemistry C, 122 (41), pp.23728-23738.
- Li, Yang, Vilathgamuwa, Mahinda, Farrell, Troy, Choi, San Shing, Tran, Ngoc Tham (2017) An equivalent circuit model of Li-ion battery based on electrochemical principles used in grid-connected energy storage applications. In Chen, Y M (Ed.), Proceedings of the 2017 IEEE 3rd International Future Energy Electronics Conference and ECCE Asia (IFEEC 2017 - ECCE Asia), pp.959-964.
- Li, Yang, Vilathgamuwa, Mahinda, Choi, San Shing, Farrell, Troy, Tran, Ngoc Tham, Teague, Joseph (2017) Optimal control of film growth in dual lithium-ion battery energy storage system. In Panda, S K, Borland, J O (Eds.), Proceedings of the 2017 IEEE 12th International Conference on Power Electronics and Drive Systems (PEDS), pp.202-207.
- Tran, Ngoc Tham, Vilathgamuwa, Mahinda, Li, Yang, Farrell, Troy, Choi, San Shing, Teague, Joe (2017) State of charge estimation of lithium ion batteries using an extended single particle model and sigma-point Kalman filter. In Kouro, S (Ed.), Proceedings of the 2017 IEEE Southern Power Electronics Conference (SPEC), pp.405-410.
- Dargaville, Steven, Farrell, Troy (2015) A least squares based finite volume method for the Cahn-Hilliard and Cahn-Hilliard-reaction equations. Journal of Computational and Applied Mathematics, 273, pp.225-244.
- Dargaville, Steven, Farrell, Troy (2013) The persistence of phase-separation in LiFePO4 with two-dimensional Li+ transport : the Cahn-Hilliard-reaction equation and the role of defects. Electrochimica Acta, 94, pp.143-158.
- Psaltis, Steven, Farrell, Troy (2011) Comparing charge transport predictions for a ternary electrolyte using the Maxwell–Stefan and Nernst–Planck equations. Journal of the Electrochemical Society, 158 (1), pp.A33-A42.
- Farrell, Troy, Psaltis, Steven (2010) A comparison of the Nernst-Planck and Maxwell-Stefan approaches to modelling multicomponent charge transport in electrolyte solutions. In Badescu, V, Paulescu, M (Eds.), Physics of Nanostructured Solar Cells, pp.327-353.
