Three-Dimensional Lattice Boltzmann Modelling the Electrode Performance of Lithium-Ion Battery

Abstract

Lithium-ion batteries (LIBs) have improved significantly over the last 20 years, and have become an important power source for portable devices, such as cellular phones, laptops, cordless power tools, and electric vehicles. The porous structure of electrodes in LIBs plays a critical role in battery performance. To further improve the performance of LIBs, there have been a lot of efforts to understand the structure-performance relation and to optimize the electrode structures. Such efforts, often dominated by the experimental trial-and-error approaches, are time consuming and expensive. Computational models, on the other hand, provide an efficient way to understand the influence of electrode microstructures on battery performance, and allow us to manipulate structure parameters easily, supporting the optimization and design of electrode structures. In current study, we report our efforts in understanding the coupled transport and reaction processes in LIBs electrodes using computational modelling, which is important for improving the performance. A three-dimensional (3D) pore-scale lattice Boltzmann model, initially developed for polymer membrane fuel cells[1] and redox flow battereis[2], has been modified and adapted to simulate LIBs electrodes. The model has the capability to simulate the ion and electron transport, coupled with the electrochemical reaction at the interface between the active material and the liquid electrolyte under complex boundary conditions. The detailed 3D microstructure of the a LIB graphite anode is obtained using X-ray computed tomography(CT). The model is applied to simulate a series of electrode structures of increasing size. The work provides evidence that the 3D pore scale lattice Boltzmann model is able to simulate the complex transport processes with real electrode geometries and predict electrochemical performance. The results show that it is important to use sufficiently large electrode structure, in order to obtain reliable structural and performance information. The simulation work help to understand the impact of electrode microstructure on electrode performance, and may lead to design principles for creating electrodes with optimal microstructure for LIBs applications. Zhang, Q. Cai, S. Gu, Three-dimensional lattice-Boltzmann model for liquid water transport and oxygen diffusion in cathode of polymer electrolyte membrane fuel cell with electrochemical reaction, Electrochimica Acta, 262(2018) 282-296. Zhang, Q. Cai, O.O. Taiwo, V. Yufit, N. P. Brandon, S. Gu, The effect of wetting area in carbon paper electrode on the performance of vanadium redox flow batteries: A three-dimensional lattice Boltzmann study, Electrochimica Acta, 283(2018) 1806-1819. Acknowledgements The authors gratefully acknowledge the financial support for this work by the UK Engineering and Physical Sciences Research Council (EPSRC) projects [grant number EP/K036548/2] and [grant number EP/R021554/1]; and the EU FP7 IPACTS [grant number 268696];