Periodic Reporting for period 1 - DEFACTO (Battery DEsign and manuFACTuring Optimization through multiphysic modelling)
Reporting period: 2020-01-01 to 2021-06-30
The project consortium combines competences in multiple fields of modelling and characterization of lithium-ion battery materials, electrodes and cells. As a result, the effects of the different production parameters and their interactions on the cell performance will be described and better understood, and the information provided by the models and simulation will result in an increase of the production’s overall efficiency, in a decrease of the time necessary to take an idea from its conception to the market and, consequently, in a reduction of the production process time and cost. This approach will be applied to the current G/NMC industrial cells and it will be extended to last generation 3b prototypes (high capacity and high voltage cells with a high Ni-content and a low Co-content with silicon-graphite composite anodes). Characterisation tests will also provide data for model development and validation, and for gaining understanding on manufacturing process parameters and cell ageing mechanisms.
Within the project, the consortium will not only generate significant information and computational tools for the acceleration of the cell development process, but also it will foster an environment that will allow the battery market in Europe to grow and strengthen. The resulting simulation tools will predict optimized cell design and cell manufacturing parameters which will be validated by prototyping and manufacturing data of advanced generation 3b cells. In particular, the validated computational simulations will be a powerful tool to (i) tailor new optimum cell designs, (ii) optimise manufacturing steps of electrode processing and electrolyte filling, and (iii) shape new generation 3b materials. Sensitivity analysis will demonstrate model robustness and reduce the number of experiments needed during cell development. The optimization algorithms will enhance cell performance and durability through optimised designs and manufacturing processes. In addition, one of the multiphysics model developed within the project will be released as an open-source simulation tool, where mechanical and electrochemical ageing mechanisms will be included at a reasonable computational cost.
In regard to the simulation of the electrode processing and the development of the needed models, relevant particle-particle and fluid-particle interactions were identified and included into the simulation framework in the first period. The developed models for the DEM and CFD-DEM simulations were published in D3.1. The models were tested for their applicability and first simulation set ups were built for the simulation of the dispersing process, the drying process and the calendering process.
Concerning the work dedicated to optimizing electrolyte filling processes, the activities were focused on pore-scale simulations of two-phase flows using the Lattice-Boltzmann method. An existing model was further developed also incorporating a homogenization approach for studying flow through nanopores without structurally resolving those. The model has been tested and validated using experimental data obtained in the project. A first parameter study has been conducted and reported in D4.1. The results indicate that the filling process and the final degree of electrode saturation are largely dependent on the porosity and the wettability of the electrode.
Furthermore, the development of simulation methods to describe and predict the electrical, electrochemical, mechanical, thermal, and ageing behaviour of the battery cells is under progress. To parameterize and justify the employed homogenized approach also microscale-resolving and atomistic methods have been developed and adapted. To investigate in particular mechanical response and ageing of the cell upon cycling and external pressure two different 3D-models that explicitly resolve the electrode microstructure have been set up: on one hand Discrete Element Methods and on the other, a continuum mechanics approach, both coupled to electrochemical simulations.
The optimization study of the cell design is in line with the work programme. So far, the implementation of reduced order techniques in the full p4D model that will predict efficiently cell behaviour is under progress. The activity has mainly consisted in preparatory work: validating the time-adaptive ROM approach. A local sensitivity study of the parameters on the electrochemical results was performed. The optimization tool has been developed and is being tested on simple problems.
In terms of manufacturing work, parameters and boundary conditions were discussed and shared to ensure a realistic set-up of the models. Measurement sensors of manufacturing partners were compared and summarized. Furthermore, G/NMC622 and G-Si/NMC811 cell electrodes have been manufactured, cells assembled and are currently being tested to generate further input for the models. Moreover, a workshop with other EU-projects was organized to discuss digital approaches in battery development.
Finally, the work to maximize the impact of the project results was defined and the elaboration of a Dissemination and Communication Plan was published in D8.2. Also, it was drafted a first market assessment and a first version of the Exploitation Plan in D8.3. An analysis of the applicable standardization landscape was carried out and the contribution to the standardization developments is ongoing. This information is further in detail in deliverables D8.9 and D8.10 respectively.