Other

Advanced Power Devices, Inc.

Volvo Technology Transfer Ab

Erik Sundberg

Ove Nilsson

This invention concerns a method of increasing the available amount of acid at PAM and NAM in lead battery electrodes and still retain a short distance between the electrode surfaces. With mechanical support of PAM (for example in tubular batteries) in spite of low PAM densities it is possible to almost completely prevent the formation of mud. Spaces for acid should therefore be mechanically strong and supporting in order to retain unchanged PAM volume. In order to prevent that the porous bodies are filled with lead powder, lead sulphate or other components during manufacture, they may be impregnated with a filler material such as for example plastic or wax which is removed after forming the electrodes or after any other suitable process. The filler material may also be an inorganic salt which dissolves only at filling with acid leaving a desired porosity.

Lead battery with acid reservoirs mixed with active material in particles

The invention concerns a lead-acid battery having all the surfaces of all the electrodes under high pressure and their circumferences kept unchanged by support from mechanically rigid cell walls such that only the thickness of the electrodes is allowed to expand under strong resilient load during the discharge and return during charge. The pressure is 0.49-10.sup.5 -9.81-10.sup.5 Pa (0.5-10 kp/cm.sup.2), and may be obtained by separators or by springs applied to the outer sides of the cell container and may be changed for increased or decreased capacity. The construction of the tubular battery design, prevents material losses due to sludging and a long working life is obtained, since also a totally corroded lead conductor under high pressure may function as a current conductor. The rigid outer containers also allow high liquid pressure and thus a high oxygen solubility and oxygen recombination for sealed cells.

Growing community of inventors

Helsingborg, Sweden

Erik Sundberg