Materials

The Fraunhofer Battery Alliance develops, optimizes and characterizes customer-specific materials and manufacturing processes for batteries. Emphasis is placed on lithium-ion systems and double-layer capacitors, and also on redox-flow and high-temperature storage devices (NaS, Na nickel chloride). Research and development work aims to increase the tolerance to external influences and improve the storage properties and intrinsic safety, paying attention to aspects of the cell manufacture.

Research, development and modification of electrode materials

Drawing on its long-standing experience in the field of material synthesis, and a close collaboration between the partner institutes, the Fraunhofer Battery Alliance develops innovative electrode materials and also offers the possibility to further develop these materials for use in industrial products.

A central underlying technology is chemical material synthesis. Examples include the synthesis of inorganic-organic hybrid polymers (ORMOCER®e), and sol-gel or solvothermal syntheses of numerous oxidic and non-oxidic materials (e.g. TiO2, Li4Ti5O12, cathode materials for lithium-ion batteries with olivine and spinel structures). Our chemical material synthesis technologies are complemented by our know-how in particle coating (core-shell structures). The Fraunhofer Battery Alliance also has competence in the field of surface modification with functional coatings (electrode layers on porous structures, protective layers, modification of the wettability of the liquids) and the manufacture of porous structures. Material development is enhanced by cutting-edge analytical facilities. These facilities are used in the context of industrial product development and optimization. Emphasis is placed on (electro)chemical analysis, nano-analysis, damage analysis, analysis of microstructures and layers, accredited product testing (DIN EN ISO/IEC 17025 – 2005), interface and surface analysis and radiography.

Improved electrolytes and separators

The Fraunhofer Battery Alliance carries out research and development in the field of materials for lithium-ion batteries, emphasizing an improved tolerance to external influences (temperature, electrical parameters), improved storage capacity and the improved intrinsic safety of the cells.

New electrolytes are also developed, which improve the operating safety of lithium-ion batteries and, in parallel, can act as separators. Inorganic-organic hybrid polymers (ORMOCER®e) are a key component in this, as their cost-efficient starting materials and ease of functionalization mean they can meet the high demands placed on electrolyte / separator systems. Properties such as stability (thermal, mechanical and electrochemical), conductivity and flammability can be adjusted through the incorporation of specific functional groups. The material development know-how available at the partner institutes means that the individual material components electrode(s), electrolyte and separator can be optimally adjusted to each other in the processing of the electrolytes / separators. Here we apply our own developments and commercial products, which can be modified as required. Cutting-edge facilities and equipment, for example impedance spectroscopy, cyclovoltammetry and Li-NMR spectroscopy enable a comprehensive analysis of the reaction processes occurring in the cell components.