Battery pack requirements

Optimizing a vehicle design is all about finding a compromise between conflicting requirements. One of the most obvious compromises is balancing vehicle range and performance. You can increase the vehicle range by increasing the size of the battery, but the vehicle will be heavier and its acceleration slower. Battery cell chemistries and formats must reach the energy density, cost and manufacturability targets the end users require. Further, batteries must be integrated into the overall vehicle architecture while its characteristics must be adequately balanced with other subsystems to reach performance targets.

Simcenter allows defining the characteristics of the battery (capacity, power, maximum current, durability...) for any kind of transportation (ground vehicles, aircraft, ships...) and stationary applications. One can generate the system architecture with functional models and minimal data to define battery requirements on certified test procedures, custom driving or working cycles.

Material & cell chemistry innovation

Extensive studies are being conducted on novel electrode materials with the goal of enhancing energy density, enabling rapid charging, and minimizing degradation over an extended period. Today, the development process is too focused on testing, which leads to long and costly developments, also limiting the number of investigated new materials.

The early-stage virtual screening of innovative battery cell materials serves as a crucial catalyst for fostering innovation. Utilizing Simcenter, product development and material scientists can digitally design new materials with desired properties, covering the entire journey from inception to process development. It includes an extensive set of tools for multiscale computational chemistry, ranging from quantum mechanics to fluid dynamics and from molecular dynamics to statistical modeling. As an example, it is possible to study the transport of ions through membranes at various conditions to predict ionic mobility and conductivity. These outputs can then be reused at the cell development level, speeding up material characterization and chemistry validation.

Battery cell development

The biggest challenge in designing batteries is increasing the energy density while maximizing battery lifespan. Consequently, cell designers seek a holistic approach that allows for precise predictions of the battery's performance, efficiency, and thermal characteristics.

Simcenter tools employ multi-scale modeling that examine the cell's behavior in detail, taking into account macroscopic and microscopic factors. Using CFD simulations, engineers can assess fluid flow, heat transfer, and electrochemical processes within the cell and can optimize various parameters, such as electrode materials, geometries, and cooling systems, to ensure the development of high-performance and reliable battery cells. Simcenter solutions for cell development ensure accurate simulations, empowering engineers to design cutting-edge battery cells that meet the stringent demands of the automotive industry.

Thermal analysis and safety

Battery cooling and heating are crucial for the pack's safety, lifetime and performance. Engineers need to develop battery thermal management systems to maintain the battery in a constant narrow range of temperatures to maximize the battery’s lifetime and minimize energy consumption. At the same time, the battery pack needs to be designed to contain thermal runaway propagation.

A smart combination of 1D and 3D simulation accelerates the development and validation of thermal management systems. Multi-domain system simulation with Simcenter supports the definition of the architecture of the thermal systems. It allows for correct sizing of the various components such as pumps and compressors, controlled valves, heat exchanger and chiller. In addition, CAD-based CFD analysis computes high-accuracy temperature map prediction in cells and packs. Simcenter proposes advanced 3D simulation such as combustion, particle ejection, deformation and melting runaway to mitigate cell thermal runaway and propagation in the pack. In addition, a smart combination of 3D and 0D/1D analysis accelerates the time to develop. By developing Reduced Order Models of accurate 3D models using AI techniques, the simulation time is accelerated hundreds of times to allow vehicle-level simulation and control validation (MiL, SiL and HiL).

Battery management system and controls

The battery management system continually monitors performance, balances the voltage between cells and prevents the battery from operating outside its safety zone. Engineers can accelerate development and validate defect-free designs and secure battery management systems using in-the-loop techniques.

As batteries involve multiple physics (electrical, fluid and thermal), it is essential to correctly simulate all related physics to validate your control strategies. Then, depending on the design stage, simple/medium/ or detailed models can be parametrized with the data available at that stage of the design cycle. Model continuity and reusability are also important: it is usually faster to adapt a model initially developed for mechanical development rather than creating a battery model from scratch. Simcenter proposes all necessary system-level multi-physic modeling levels and model reduction techniques to provide control engineers with meaningful battery and subsystem models (such as thermal management).

These multi-physic models can be linked to control strategy models, exported to be connected to controller C-code, or exported to the classical Real-Time hardware such as dSPACE, Speedgoat or OPAL-RT.

Pack integration

A battery pack is heavy. It can make up as much as 25% of the overall vehicle mass. Apart from the impact on energy consumption or driving range, the extra weight might cause new durability issues that do not occur on vehicles with an internal combustion engine. Simcenter solutions help understand the road loads in combination with battery-induced loads impacting the battery as well as the whole vehicle and validate design against real-life usage through vibration qualification testing.

When integrating battery packs into the vehicle, a structured durability engineering process can detect potential fatigue problems. To do so, we focus on three criteria: realistic load utilization based on real-life measurements, a correct profile determination using damage potential analysis over a real customer usage profile, and a test execution with a good level of acceleration.

From advanced data acquisition, target profile creation, and lab-based test campaigns, our solutions help you define the right vibration targets and avoid testing too much or too little.