BMBF junior group „Kems4Bats“

The heat and gas development within the battery can have various reasons. One of them is the formation of the so-called Solid-Electrolyte-Interface. This is a protective layer on the anode. It is crucial for the performance and stability of the battery. Decomposition reactions of the battery materials can also lead to significant gas and heat development. In the worst case, this can result in what is known as Thermal Runaway, which destroys the battery.

We are further developing battery calorimetry and KEMS methodology together with the industry to better determine fundamental material properties and to better understand chemical-physical processes such as phase transitions, decomposition reactions, and their kinetics using innovative experimental analytical methods.

We investigate aging effects of battery materials of various material chemistries and (micro-) nanostructuring. The battery materials should potentially be suitable for High Power Charging. Charging a battery within 15 minutes while simultaneously increasing energy density and longevity.

The research group Kems4Bats is supported by the Federal Ministry of Education and Research (BMBF) and by industry and academic sponsors.

It is directly linked to the Federal Government's High-Tech Strategy 2025 based on the BMBF framework program "From Material to Innovation".

Industrial Advisory Board

Scientific Advisory Board

Research projects

State of Health

In the research project "SOH," a battery sensor is being developed based on impedance spectroscopy measurements. The collected data will be evaluated on the battery sensor using innovative software based on neural networks.

The state of charge (SOC) and the state of health (SOH) are only estimated in electrified vehicles. The miniaturized sensor is intended to be used for the first time in the space-limited area of electric cars. It is supposed to accurately determine the current state of charge (SOC) as well as the heat flow. Thermal runaway can thus be prevented.

Battery aging losses are intended to be considered for the first time in range forecasts. Information such as the driver's driving style, the planned route, and environmental influences such as weather will be taken into account in the evaluation.

The project is funded by the Federal Ministry for Economic Affairs and Climate Action (BMWK) with industry participation.

Battery-Recycling

In the research project "BaKaRe," a new, energy-efficient, and environmentally friendly recycling process for lithium-containing used batteries is being developed.

The purity of the recovered lithium-containing components should be at least 90%. Due to the increasing demand for lithium-ion batteries, environmentally questionable methods, and strong regional dependencies in lithium extraction, there is a great interest in technologically new and economically viable processes for improved lithium recycling.

The process will work without chemical or hydrometallurgical treatment. For this purpose, a special milling process will be complemented by sensor-based monitoring.

Due to the rapidly growing segment of battery manufacturers, a future high market demand for recycled battery materials is expected due to the equally increasing demand for raw materials.

The project is funded by the Federal Ministry for Economic Affairs and Climate Action (BMWK) with industry participation.

Battery Production

In the research project "Bat-Production," a dedicated battery production setup is being established on a laboratory scale. The entire process chain of battery production is being replicated, starting from the preparation of battery powders, coating of current collectors, and necessary drying processes.

The batteries produced (pouch or cylindrical cells) are sized to be used in the electric vehicle of our "Delta-Racing Team" as an example.

Additionally, the material properties of the self-produced battery materials can be examined in special test systems.

For example, we determine the Li diffusion coefficient via electrochemical impedance spectroscopy (EIS), an important parameter when it comes to fast battery charging (Power Charging).

But also, classical measurements on individual electrodes can be carried out:

• How much energy can the electrode material store?

• How many times can I charge and discharge my electrode material?

• How thermally stable is the new electrode material?

The project is accompanied by the BMBF junior research group Kems4Bats. Financial support is provided by the General Student Committee (AStA / QS funds) and Volkswagen AG.

Battery Test Center

In the research project "Bat-Cave," a battery testing center is being established, where larger battery modules can be tested in a safe environment. The capacity and aging state can be determined with high precision.

In special climate chambers, individual battery cells as well as larger battery modules can be charged and discharged within a temperature range between -10°C and 100°C. Important battery performance parameters can be identified using our high-precision "Current & Voltage Booster" to design a battery module for an electric vehicle that is both efficient and safe.

How much energy can be stored at different temperatures and load conditions?

What is the aging state? State of Health?

The project is accompanied by the BMBF junior research group Kems4Bats. Financial support is provided by the General Student Committee (AStA / QS funds) and the Faculty of Mechanical Engineering.

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