Li-ion Cell Materials & Transport Modelling

Topic Description

Europe is strong in research capabilities, the ability to industrialize products and competences in terms of material research related to battery chemistry. However, the step towards large-scale mass production of competitive battery technology (mainly Li-ion / advanced Li-ion) has not been established so far and still requires fundamental research. Especially when moving to cell materials beyond conventional Li-Ion battery for mobility applications, it is no longer possible to rely on classic cell design methodology to achieve the ambitious goals set for cell technology after 2025 (both generation 3b and generation 4). As such, advanced modelling and simulation tools are required that specifically target the electrode and cell level and addressing the fundamental understanding of materials and cell behavior. These tools are vital to support future cell development, but require significant advancements in order to meet this challenge. Not only the material characterization must be considered, but in particular the validation of the models and simulation tools must be of utmost priority.

These efforts will require sufficient prototype manufacturing of cells to measure and validate, and is expected to result in a key cornerstone in the overall framework needed to improve European competitiveness in cell design and manufacture. Via a highly dynamical iterative exchange process between prototyping, simulation and newly developed analytical tools an accelerated development process can be established, leading to a significantly accelerated adoption of new battery technologies to the market.

Proposals should address all of the following items:

• Advanced modelling approaches based on different physical domains correctly describing the behaviour of micro-structures in advanced Li-ion cell chemistries and 3D structure, but also considering packing conditions under arbitrary usage scenarios. The new model approaches should be able to take into account the behavior, performance and both homogeneous and inhomogeneous/heterogeneous ageing
• Systematic measurements of basic input parameters for modelling (like heat coefficients, diffusion coefficients, conductivity etc. ) to establish a reliable data base for these parameters. This may require measurement techniques and methodologies that may not even currently exist, in order to sufficiently confirm that the simulation data, results and predictions to match the actual cell behavior observed (this could also include new measurement tools to monitor changes in electrode structure or cells, for example mechanical stresses, changes in porosity, microstructure) including complete cell behavior (with respect to formation and cycling) needed for the simulation models and future progress with new advanced modelling approaches.
• Manufacture of prototype cells or cell components with distinctive features to allow 1) generating input parameters to initialize the model, and 2) validating the usability of the simulation models and, at the same time, being clearly conform with future industrialization efforts. Cooperation with projects in LC-BAT-5-2019 can provide support to design, manufacturing and sensitization aspects.
• Demonstrate sufficient correlation between cell measurements and simulation, especially for all relevant cell design needs, as well as the validity and robustness of the models for multiple test variations which account for the relatively big state-space of electrochemical systems. (models should not be just optimized for one particular test case, but also show good correlation with valid test variations).

Additionally some specific aspects can be also considered, such as:

• Sensitivity analysis on model parameters to assess governing parameters and model robustness can also be performed to allow an efficient calibration method and experimentation.
• Investigation of tolerances for cell production by means of simulation, study and prediction failure propagation and consequences on ageing and safety.
• Assessment of EOL properties of newly high optimized (>300Wh/kg) developed cell chemistries based on combined simulation / experimental validation approach, referring to automotive standards & requirements.
• Investigation of new methodologies and procedures to shorten the endurance validation of cells, in terms of functionalities, ageing and safety.

For future battery industry collaborative round-table approaches would achieve a considerable gain, bringing together the whole value chain from academia to the OEM. Furthermore, this can bring together representatives from experimental & simulation fields of expertise, exchanging their knowledge via a structured approach.

The activities should thus focus on a multidisciplinary approach from fields of expertise in simulation and experimental field, investigating battery chemistries most relevant for the automotive field in the next 5-10 years and oriented on the specific ERTRAC energy density targets for advanced Li-ion technologies (generation 3b). By means of such a round table approach; at least TRL 5 level or above is aspired. The synergetic development approach by combining simulation and rapid prototyping on the experimental side is expected to speed up the development processes of battery technologies relevant for cell production in Europe, targeting the automotive market.

The Commission considers that proposals requesting a contribution from the EU between EUR 3 to 6 million would allow this specific challenge to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts.

The final simulation solution should not increase significantly computing costs and should be compatible with available computing resources in modern engineering workplace, while providing the following benefits:

• Reduce the development time and cost for battery cell up to 30% each.
• Get a better optimum of the design thanks to the analysis based on different physical domains.
• Demonstrate the potential for reduction of number of experiments by factor 3, for the overall development process.
• Reduce battery R&I cost by 20%

It is expected that progress in the area of new and innovative measurement technologies would lead, at some point, to standardized measurement procedures.