Electrical Energy Storage

Electrical energy storages are essential for the reorganization of the energy system. In this field, we focus on the development of batteries and SuperCaps. The applications of batteries are numerous and range from compact mobile entertainment and communication devices, batteries for hybrid and electrical vehicles through to storages for renewables with MW/MWh capacities. The common development goal of these fields of applications is an ideally high energy and power density, which means short loading and unloading times. A reliable operation and a long durability are further features.

Redox-flow batteries are a pioneering technology for the energy storage with high outputs (megawatts). The stored energy is held in external tanks and can be converted in the conversion unit when needed. They offer the possibility of individually adjusting power (kW) and energy (kWh) of the application. The applications range from the storage of renewables from fluctuating renewable energy sources and the possible usage as almost continuously available energy storage in the grid through to the uninterruptible power supply.

Rechargeable lithium-ion batteries are increasingly used in all areas of daily life and also gain importance as stationary temporary energy storage.

Advantages of the lithium-ion battery include its low self-discharge rate, the fact that there is no considerable memory effect and its high energy density. Especially the electric mobility in form of e-cars or e-bikes makes use of the high energy density in order to achieve a long range. In addition to the development of materials, their processing and process engineering, battery management and monitoring as well as investigations into the security of these energy storages are also at the focus of the Fraunhofer Energy Alliance.

With their very high power density and related short retrieval and charging times, double-layer capacitors are an alternative or complement to battery technologies. Researchers at Fraunhofer are committed to improve these SuperCaps by using new materials and coating technologies.

Competences »Electrical Energy Storage« | Fraunhofer Energy Alliance

Material Development for Batteries

As the basis for the energy storage systems of the future, scientists of the Fraunhofer Energy Alliance are working on the development and analysis of numerous material components. Compared to existing energy storage systems, durable storage systems with high cycle stability, low costs and high safety must be considered and developed for stationary applications. For tomorrow's electromobility, on the other hand, storage devices with high energy and power density - i.e. shorter charging times - at lower costs and greater safety are crucial. To this end, our member institutes conduct research on the optimization of components and numerous materials and their combinations for redox flow batteries and high-temperature batteries, as well as for lithium sulfur cells and solid state batteries. Researchers at Fraunhofer also carry out material tests in standardized systems, which can be used to record physical parameters and compare them with the current state of storage technology.




In the framework of the RedoxWind project, a large-scale redox-flow battery storage device will be developed and connected directly to the intermediate DC circuit of a wind turbine.



Battery technology of the future - With EMBATT, Fraunhofer IKTS is creating an innovative design for bipolar batteries.

Battery Technologies (Li-Ion, LiS, LiO2, ASSB, Pb, NaS, NaNiCl, RFB)

One focus of the Fraunhofer Energy Alliance is research into energy storage systems, for example for stationary applications or electromobility. In the technical implementation of novel stationary battery concepts, cost reduction, efficiency, durability and cycle stability as well as operational safety are the most important features. For electromobile applications, battery concepts are evaluated on the basis of their compactness and energy density as well as their cost and operational reliability. For this purpose the development and optimization of problem-adapted storage solutions takes place. In addition, sustainability and environmental friendliness are also considered, for example in the development of Na batteries or redox flow batteries from locally available, non-strategic base materials or efficient manufacturing processes for lithium batteries or redox flow batteries. The eco-design and recycling of batteries, for which our member institutes identify best practices for economic and ecological optimization, also serves this purpose. Data on physical and electrochemical processes in different batteries can be obtained in specially developed simulation environments. In addition, our battery emulations - virtual batteries - allow the optimization of battery management systems (BMS). Furthermore, the data obtained from the simulations and practical investigations support the design of energy storage facilities (storage systems) as well as mini- or microgrids and enable a techno-economic evaluation of storage technologies.




cerenergy® is the Fraunhofer IKTS technology platform for ceramic-based high-temperature batteries.


Redox Battery

Researchers at the Fraunhofer Institute UMSICHT have developed a 3.2 m² bipolar plate that enables large-scale redox flow batteries to be built.


Compared to accumulators, power- or supercaps have a multiple of the power density and thus shorter charging times, but with only a small fraction of the electrical storage capacity. They therefore represent a promising alternative or supplement to battery technologies. Researchers at Fraunhofer are committed to improve these supercaps by using new materials and coating technologies. We combine the advantages of batteries and supercaps in specially developed hybrid storage units, which are used in motor vehicles, for example.




Within the scope of the Horizon 2020 project “NETfficient”, the power distribution grid on the North Sea island of Borkum is equipped with a high proportion of renewable energies and diverse storage technologies.

Management and Monitoring of Batteries

Research at the Fraunhofer Energy Alliance on electrochemical energy storage systems also deals with battery management systems and battery monitoring from the aspect of safe operation, monitoring and diagnosis. The competencies of our member institutes include battery simulation and emulation, the development of battery management software and algorithms as well as remote battery (system) diagnosis with regard to ageing, residual value and lifetime prognosis. Furthermore, the Fraunhofer Energy Alliance offers tests of battery management systems using special test systems.




foxBMS is a free, open and flexible research and development environment for the design of battery management systems. Above all, it is the first universal hardware and software platform providing a fully open source BMS development platform.