Energy storage

Energy storage systems are a key element for the success of the energy transition. They enable the (partial) decoupling of energy production and energy consumption. Today, they are used in particular in the areas of mobility and heat supply, and their importance is steadily increasing. At the same time, they are opening up further applications such as stationary energy storage for grid stabilization and for optimizing the operation of electrolysers. Thermal energy storage systems cover both short (day/night) and long-term (seasonal) periods. In the industrial environment, thermal storage is used for waste heat recovery.

Improvements at cell and battery system level as key for electrical energy storage systems

Electrochemical energy storage systems play a decisive role in stationary applications in the form of intermediate storage for regenerative energies and in mobile applications. In particular, the ever-increasing functional density in the consumer sector and the high demands placed on electric vehicles require powerful and reliable energy storage systems. According to numerous roadmaps, lithium-ion technology in particular will play the dominant role in the coming years.  

In particular, vehicle-compatible electrical energy storage systems must also fulfill a very broad, sometimes contradictory range of requirements. This includes parameters such as:

• costs
• energy and power density
• lifetime
• a wide temperature range and
• operational reliability.

In addition to optimizations at the battery system level, improvements at the cell level play a special role and are the key to future electrical energy storage systems. Crucial to the development of third- or fourth-generation batteries is a close dovetailing of applied materials research and the associated process technology.

Development of innovative and highly efficient latent heat storage systems

A large part of national energy consumption is accounted for by thermal use, e.g. for process heat and heating. The optimization of thermal energy consumption and the provision of thermal energy in line with demand accordingly plays a major role in achieving climate targets. The storage of thermal energy is a central component here, since the availability and use of thermal energy can be separated from each other in terms of both time and location. Thermal energy storage can be used to provide heat, but also for the important application areas of cooling and air conditioning. 

The focus of Fraunhofer IFAM in the field of thermal energy storage is on the development of innovative and highly efficient latent heat storage systems. Here, the phase change of a storage material between solid and liquid state at almost constant temperature is applied. In addition, the topic of sorptive heat storage using the physical effect of adsorption is also addressed.  

Fraunhofer IFAM combines the necessary materials science and energy technology expertise for the development of optimum heat storage systems. This includes the extensive and well-founded characterization of the storage materials as well as the entire storage system. But also the selection and (further) development of suitable container materials and heat conduction structures are pursued. Attention is also paid to the requirements regarding the application temperature and the interactions with the storage materials. In addition, there are many years of experience in the conception, simulation and design of the storage tanks.  

Fraunhofer IFAM has more than 15 years of experience in the application of polymer and inorganic materials in energy storage technology, with a focus on lithium and post-lithium battery concepts as well as latent and sorptive heat storage systems. Based on the institute's core competencies in powder technology, shaping, surface technology, adhesive bonding technology and interfacial/polymer chemistry, solutions motivated by materials science and manufacturing technology are developed for novel energy storage systems. The entire value chain from materials, components and cells to the battery system and its application is taken into account. 

In various joint projects with partners from industry and research, Fraunhofer IFAM is working on research into current and next-generation storage technologies. The focus will be both on the storage device itself and on their manufacturing processes. In addition to the issues of material selection and material design, the associated process technology for manufacturing on an industrial scale will be worked on. Furthermore, the modeling and diagnostics of storage systems form the basis for aging forecasts and associated operating strategies.