Project examples in battery research at Fraunhofer

The Fraunhofer-Gesellschaft is active in every area of battery research. The goal of the initiative and projects is to lower the production costs of batteries, to increase their energy density based on innovative material combinations and new cell designs, and to make batteries and the scenarios for their application safer. Below we will be presenting several projects.

New battery technologies

© Fraunhofer IKTS

"EMBATT" – Greater energy density and range as a result of stack construction

Fraunhofer Institute for Ceramic Technologies and Systems IKTS is working together with industrial partners on the "EMBATT" project to develop materials and processes to efficiently manufacture a large-format bipolar battery. The aim is to improve the energy density of batteries by constructing bipolar electrodes. To this end, the battery components are stacked in such a way so as to eliminate the laborious packing and connecting of the individual cells, and resistance within the stack is reduced. This way, the higher energy density at the cell level can be transferred directly to the stack and so to the entire battery system. Cathode materials with defined specifications are required for this stacked construction, and Fraunhofer IKTS is developing this part of the project. The experts are also currently working on other battery components, such as anodes, electrolytes and conductor foil, as well as seals for the bipolar stack design. It is hoped that the EMBATT technology will deliver a high energy density of 450 Wh/L at the system level, at a planned production cost of <200 €/kWh. In the future, this could allow electric cars to achieve ranges needed for everyday use. This will make an important contribution to the success of electromobility.

"MASAK" – Magnesium sulfide rechargeable battery for energy storage

It is possible to avoid the rare or poisonous (and therefore expensive) materials which typically make up lithium-ion batteries through the use of alternative materials. In the "MASAK" group project, Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM is researching high-performance rechargeable batteries with a high energy density not based on lithium. Instead of lithium, the project researchers are using magnesium as an electrode material and are developing magnesium sulfide batteries. This makes magnesium sulfide batteries a cost effective alternative that is likely to achieve 150 Wh/kg in practical use.

Berührungslose Messung der Ausdehnung einer Lithium-Ionen-Pouchzelle während der Zyklisierung
© Fraunhofer ISE

"OrtOptZelle" – Position-Dependent Compression of Battery Pouch Cells for Life-time Optimization

During charging and discharging, lithium-ion batteries undergo both reversible and irreversible thickness expansion. This can lead to a substantial mechanical load inside the battery cell causing delamination or short-cut of the electrodes. The increase in the battery thickness can also cause pressure on the neighboring battery cells in case of stapled module. These mechanical loads have a direct impact on the service life and reliability of the battery cells and can lead to safety issues. The central goal of the project “OrtOptZelle”, in which Fraunhofer Institute for Solar Energy Systems ISE is involved, is to identify the area distribution of the changes in volume and pressure on the cell. It involves the precisely measurement of these volume changes during the charging and discharging processes, generating a spatially resolved map and then correlating it with the aging of the cells. Aiming the increase in their service life locally distinguished external compression will be applied on the cells during operation. The findings of this project should contribute in particular to the improvement of the battery cells during their operation regarding the aging process, reliability and safety as well as a hint for an appropriate module design.

Fraunhofer ISE – OrtOptZelle

BEMA2020: Accompanying research on battery materials for future mobile and stationary applications (Batterie 2020)

The German Federal Ministry of Education and Research (BMBF) is supporting research on new kinds of battery technologies with different funding measures. The aim is to develop and expand the scientific and industrial basis of battery research to advance Germany towards becoming a lead supplier of key technologies for e-mobility. The aim of the BMBF funding program “Batterie 2020” is to consider material and process developments in a systemic context and to significantly improve battery properties such as energy density, power density, lifespan, safety, aging and costs. Fraunhofer Institute for Systems and Innovation Research ISI has been accompanying these processes from the very beginning with a national roadmapping process (LIB 2015-Roadmapping) within the BMBF-Innovationsallianz LIB 2015 and, since 2011, additionally with an international monitoring process (Energy Storage Monitoring) within de BMBF funding measure “Key Technologies for Electromobility STROM”.

Cell production

© Fraunhofer IPA

"LoCoTroP" – Department Electrochemistry and Batteries

Solvent-based processes represent the state of the art in the production of battery electrodes. Following the coating of the electrodes, the solvent must be evaporated and reclaimed using laborious, costly drying processes. To save on these costs during production, Fraunhofer Institute for Manufacturing Engineering and Automation IPA, together with its partners, is conducting research as part of the "LoCoTroP" Department Electrochemistry and Batteries.

Fraunhofer IPA – LoCoTroP

"OptiEx" - Optimized Manufacturing Processes for High-Load Electrodes

For lithium-ion batteries to find widespread use in electromobility and stationary energy storage applications, manufacturing costs must be lowered. Fraunhofer Institute for Ceramic Technologies and Systems IKTS is developing an innovative pilot line for solvent-reduced electrode production. In this way the complete Li-ion manufacturing chain can be mapped and specifically optimized. One core activity is the scale-up and optimization of coating and production technologies for efficient, resource-saving, reproducible mass production of lithium-ion batteries. Special inline and offline analytics are used to analyze the processes and identify process-related interactions.

Fraunhofer IKTS – OptiEx / Application center battery technology

"Cell-Fill" – Optimized Filling and Wetting Processes

The electrolyte filling of a lithium-ion battery and the subsequent wetting are essential process steps in battery production and represent the interface between cell assembly and formation. Up to now, there has been almost no scientific research on these processes. As part of the project “Cell-Fill”, Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Fraunhofer Institute for Silicate Research ISC and Fraunhofer Institute for Industrial Mathematics ITWM, in cooperation with other project partners including the MEET at University of Münster and the PEM Chair at RWTH Aachen University, are researching the development of process-structure-property relationships for filling and wetting processes. They investigate which product and pro-cess parameters govern the electrolyte filling and how changes of the wetting time affect cell performance.

ProZell – Cell-Fill 

Perspectives for carbon-neutral battery production in Germany

Commissioned by the Agora Verkehrswende, Fraunhofer Institute for Systems and Innovation Research ISI conducted a study on the prospects for climate-neutral battery production for electromobility in Germany. Many aspects are important to realize more sustainable battery production, from extracting the raw materials through to closed-loop recycling. The focus of this project is on reducing the greenhouse gas emissions produced when manufacturing batteries. Various measures are identified and classified within this project that decrease the greenhouse emissions, especially CO2, in battery cell production.

Materials research

© Fraunhofer ISE

"FliBatt" – Solid Lithium Batteries with Non-Woven Materials

Fraunhofer Institute for Solar Energy Systems ISE has been working together with other project partners on the development of a novel battery cell architecture for the realization of solid-state batteries. In all-solid-state batteries the liquid electrolyte is re-placed by a solid non-combustible ion conductor. This prevents thermal runaway and significantly increases the safety of battery cells. It also facilitates the use of lithium metal anodes, which makes higher energy densities and thus significantly higher ranges for electric vehicles possible. The project aim is the development of an innovative process for a new cell structure that shall enable a cost-effective manufacturing process for the production of solid state batteries. Fraunhofer ISE is developing the starting materials for the electrode coating processes and the separator layer. These will be accessible to the partners so that they may optimize the coating processes. Furthermore, Fraunhofer ISE is building and characterizing the battery cells.

Fraunhofer ISE – FliBatt