SIERRA

Safe, sustainable, lIghtwEight and high-perfoRmance Ni-Rich NMC battery pack with Advanced cell-to-pack monitoring for decarbonising heavy-duty vehicles

Abstact:

In the HDV market, the main considerations for battery packs are safety, durability and mass energy density. High-energy NMC cells are very appealing for achieving the target for future battery packs. However, further developments are needed for high-energy NMC battery packs to meet the stringent safety and durability standards of the HDV market.

Additional factor to achieve high mass energy density is reducing the weight of the battery pack, but lightweight structures are less common in HDV due to safety and durability constraints.

To respond to these challenges, SIERRA project will develop a safe, sustainable, lightweight and high-performance Ni-rich NMC battery pack with advanced cell-to-pack monitoring for decarbonising HDV. SIERRA project will propose several innovations:

1. Multiscale modelling of the battery pack to propose compact pack design and to simulate its thermal and mechanical behaviour;
2. One-shot manufacturing of lightweight multimaterials casings with low environment impact;
3. Mutli-scale advanced monitoring (SHM, thermal mapping, SoC, SoH) and reduction of the complexity of BMS architecture;
4. Full integrated cooling system and printed busbars to respond to fast charging requirements and increase performance over the complete operational conditions.

The specific use case targeted by the project is the bus market, and SIERRA battery pack will be validated at TRL6 for this market. The integration into the vehicle will be simulated using a digital twin. All SIERRA activities will follow the methodology defined by the SSbD framework.

SIERRA consortium is composed of 11 partners (+60% industrials), all with exceptional R&D platforms and proven track records. SIERRA battery pack sales are projected to generate a total cash flow of €87 million between 2030 and 2034, accompanied by the creation of 525 jobs, thereby contributing to the expansion of the EU clean mobility market. SIERRA project will also generate 13 KERs and 8 patents.

Leitat’s Role in the Project:

Leitat’s primary role in the project is to design and manufacture 3D printed busbars using Laser Powder Bed Fusion (LPBF) technology. This involves three main steps:

• Design Tools and Strategies: Develop design tools and strategies to overcome the limitations of conventional manufacturing. This includes considering Design for Manufacturing (DFM) criteria and Computational Fluid Dynamics (CFD) thermal simulation results.
• Material Characterization: Manufacture 3D printed coupons and characterize their properties, such as hardness, microstructure, thermal, and electrical properties. Heat treatment and chemical polishing will be applied to optimize these properties and ensure proper surface roughness for electrical contact.
• Configuration Selection: Select the most promising configurations in agreement with VER, and deliver the printed busbars to project partners.