With the eighth contribution to our »SkillandScaleUp« information campaign, we are moving into the second central research area: digitalized battery cell production. It is important to understand what challenges battery production still faces that can be solved with the help of Industry 4.0 principles. The use of digital twins offers a wide range of potential here.
Digital technologies play an important role in the production of battery cells. To date, many production steps are still based on analogue, fairly rigid processes and experience-based parameters compared to digital, adaptive and adaptable processes. The end-to-end digitalization of the value chain is a key enabler for more sustainable battery production - as is the case at Fraunhofer FFB. It enables countless data to be recorded and processes to be controlled more efficiently: From tracing the properties of the individual battery cell, to the thickness of the coating applied, to the optimum control of room temperature and humidity - in other words, the entire production process will in future not only take place in the »FFB PreFab« in real terms, but also virtually.
The aim of Industry 4.0 is the complete digitalization of production. The advantages are obvious: a networked and intelligently producing factory works efficiently, with high quality and in a resource-saving manner. The use of digital technologies is essential, particularly for the production of battery cells, which is currently still characterized by high costs and reject rates.
The development of digital workflows and automated production processes requires, above all, resourceful engineers and open markets that enable the development and technical implementation of a comprehensive digitalization strategy for the efficient and sustainable use of battery data. In this way, all data generated along the entire production process can be profitably linked. The development of this requires the complete digitalization of all methods and processes for data generation and processing. Digital twins as an image of a physical counterpart have great potential for battery cell production.
Digital Twins make it possible to test new processes and technologies in a simulation environment. They are closely linked, virtual copies of physical objects. The idea is not new: to test problems and their solutions, NASA built exact replicas of the spaceships used in space on Earth back in the 1970s. What was implemented in analogue form back then is now taking place in digital space.
The digital twin can precisely reflect an object with the help of data, information, and models. The object can only be a real, tangible, physical object. The mapping of processes is only possible through the interaction of several digital twins. An object can be of a physical nature, such as a plant or a building, or of a virtual nature, such as a plan or a process. The overarching goals that are to be achieved with the help of a digital twin include obtaining and analyzing information, providing information, supporting decision-making and controlling autonomous systems. The added value of a digital twin lies, for example, in the predictive maintenance of systems, the quality prediction of products, virtual commissioning and the traceability of the battery cell throughout the entire production process.
A distinction is made between three types of digital twin for battery cell production:
At the digital plant twin, the main focus is on the production systems in battery cell production. It digitalizes all processes of the production systems in the factory. This allows, for example, the condition of machines to be monitored and decisions to be made based on this, reducing wear and tear, and shortening maintenance times. The efficiency of the plant is increased as the data can be viewed in a coherent manner. This leads to more economical and ecological production.
In contrast to the plant twin, the product twin collects all data and characteristics of raw materials as well as intermediate and end products, including the parameters of the manufacturing processes. This enables, for example, the traceability of trickling solids and flowing pastes. Currently, slurry paste, for example, is still produced in individual batches during mixing. The digital product twin can support a continuous mixing process. In addition, a digital product twin can be used to analyze the usage data of each individual battery in combination with the stored product data and thus influence the decision on the secondary reuse and recycling of these batteries.
There is a great need for energy-intensive clean and dry rooms, especially for battery cell production. The digital building twin is based on the existing Building Information Modelling (BIM) and increases the efficiency of the planning and operation of factory buildings by digitally mapping the building in all construction and operating phases. The increase in efficiency consequently reduces costs and CO2 emissions.
Through their interaction, the various digital twins enable overarching knowledge gains and optimization. It is important that they are customized to the respective application during implementation in a battery cell factory and that all users are involved in the development process at an early stage. In this way, new and improved battery cells can be developed and production optimized within a very short space of time using all of the data from production and use stored in the digital twin.
Talk to an expert: this was the motto of our first Live Q&A on 20 March 2023. In keeping with the topic, the experts were available in a double pack: Head of Department for the Digitalization of Battery Cell Production Dr. Jonathan Krauß and Group Manager for Data Acquisition and Aggregation Arno Schmetz answer all questions about the digital twin in battery cell production in the YouTube video.
Fraunhofer Research Institution for Battery Cell Production FFB