Low cost, ceramic battery components and cell design

Na/NiCl2 batteries represent a high-energy-density battery concept based on abundant, low cost-materials. The current production process of the solid state electrolyte is the driving cost factor in this field. IKTS develops improved technologies for the highly efficient production of this price-determining core component – the ceramic sodium β-alumina electrolyte. Furthermore, by simplifying the cell design regarding the manufacturing technology, the aimed target costs amount to below 200 EUR/kWh at cell level. Starting with a lab-scale screening of powder synthesis, several routes for electrolyte shaping are under development. Boehmite based β-aluminas reached ionic conductivities of about 0.241 S/cm at 300°C with a highly dense microstructure and a β”-phase content of > 97 %. The powder processing was transferred to pilot scale and different shaping technologies were evaluated. Electrolyte tubes with a length of 30 cm were manufactured by isostatic pressing. For the stiff plastic extrusion the preparation of the mass was developed. Densities of about 96 % after sintering were achieved this way. So far, different cell designs have been realized.