Comparison Between Flat Plate and Tubular Na/MCl2 Cell Designs
All beta batteries in production use tubular beta alumina configurations and flat plate designs are under development. On the example of the Na/MCl2 chemical system the two design options will be compared with respect to technological, performance and production considerations. The main geometric parameters are the tube radius rt and tube length l for the tubular design and disk radius rd and cathode height h for the plate design. Energy E is proportional to the active mass volume whereas peak power P is proportional to the beta surface. This results in: E/P~rt/2 for the tubular design with the constraint for l<20rt. and for the disk design E/P ~h for which the limits will be presented. Technological considerations include the sealing which is at least by a factor of 3 longer for the flat plate design, and the beta production, for which the disk can be produced in a simple unidirectional press whereas the tubes are produced by isostatic pressing.
Dr. Cord-H. Dustmann is founder and managing director of Battery Consult AG. He studied at KIT, first worked on superconducting magnets and than on sodium batteries, in particular in Na/MCl2 systems. He founded Battery Consult in 2008.