Computational Homogenization of Mechanical and Electro-Chemical Properties in Structural Battery Electrolytes
Doktorsavhandling, 2024
The first part of the thesis studies the multifunctional performance of various SBE microstructures by performing virtual material testing on numerically generated artificial Representative Volume Elements (RVEs). In particular, the effective ionic conductivity is obtained by solving a diffusion equation with Fick's law, and the effective stiffness by assuming linear elasticity. As a direct extension of this framework, coupled diffusion and large deformation in the SBE is also considered; i.e., ionic transport in an SBE subjected to mechanical loads using finite strain theory. Here, the aim is to compute the deformation-dependent effective mobility.
The second part covers the development of a multi-scale modeling framework for electro-chemically coupled ion transport in SBEs. After establishing the governing equations, Variationally Consistent Homogenization (VCH) is employed to obtain a two-scale model. If the sub-scale RVE problem exhibits negligible transient effects for length scales relevant to the studied application, then the assumption of micro-stationarity can be introduced. This opens up for the possibility to devise a numerically efficient solution scheme for the macro-scale problem that is based on a priori upscaling of the effective response.
Lastly, Numerical Model Reduction (NMR) is exploited to enable solution of fully transient electro-chemically coupled two-scale problems without assuming micro-stationarity. The goal is to exploit NMR by training a surrogate model, via Proper Orthogonal Decomposition (POD), that replaces the RVE simulations. The surrogate model takes the form of a system of Ordinary Differential Equations (ODE). The final NMR framework leads to a computationally efficient solution scheme for solving fully transient two-scale problems.
Multi-scale Modeling
Multiphysics Modeling
Multifunctional Materials
FEM
Computational Homogenization
Numerical Model Reduction
Författare
Vinh Tu
Chalmers, Industri- och materialvetenskap, Material- och beräkningsmekanik
Performance of Bicontinuous Structural Electrolytes
Multifunctional Materials,; Vol. 3(2020)
Artikel i vetenskaplig tidskrift
Variationally consistent homogenization of electrochemical ion transport in a porous structural battery electrolyte
European Journal of Mechanics, A/Solids,; Vol. 98(2023)
Artikel i vetenskaplig tidskrift
Numerical model reduction of multi-scale electrochemical ion transport
Deformation-dependent ionic transport in Structural Battery Electrolytes
In the quest for weight efficient energy storage solutions, the so-called "structural battery" is an emerging technology under development. It is a multifunctional composite material that offers weight-efficient energy storage by combining mechanical load-bearing and battery functionalities. Carbon fibers serve as both structural reinforcement and electrodes, embedded in a structural battery electrolyte (SBE) composed of a solid polymer skeleton and liquid electrolyte.
In this thesis, we investigate a key component of the structural battery, specifically the SBE. Our goal is to simulate the behavior and properties of the SBE by developing computer models. Rather than testing and experimenting with SBE designs in a laboratory, computer simulations now allow us to perform virtual experiments. To the naked eye, the SBE might appear as a smooth material; however, upon zooming in, it is revealed to be a porous medium. This poses significant technical challenges, as it is computationally expensive to capture both small- and large-scale effects in a single simulation. Consequently, a major focus of the thesis has been on developing a multi-scale modeling framework to address these challenges.
Modellering och beräkningsbaserad homogenisering av ett poröst medium med vätsketransport i ett nätverk av propagerande sprickor
Vetenskapsrådet (VR) (2017-05192), 2018-01-01 -- 2022-12-31.
Ämneskategorier
Teknisk mekanik
Energiteknik
Kompositmaterial och -teknik
ISBN
978-91-8103-075-4
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5533
Utgivare
Chalmers
Virtual Development Laboratory (VDL), Chalmers Tvärgata 4C, Gothenburg
Opponent: Professor Varvara Kouznetsova, Mechanical Engineering Department, Eindhoven University of Technology (TU/e), Netherlands