Aktiebolaget Tudor

Other

Esb Incorporated

Advanced Power Devices, Inc.

Volvo Technology Transfer Ab

Ove Nilsson

Erik Sundberg

Gunnar Eckerbom

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.

Lead battery

Bipolar battery and method of making a partition wall for such a battery

An improvement in the production of tube electrodes for lead storage batteries comprising mixing a small amount (0.1 to 3 weight percent) of polytetrafluoroethylene (PTFE) with lead powder, the mixture is heated and shear stresses are applied thereto sufficient to convert substantially all of the PTFE in the mixture to fibrous form and to form a non-powdery dough. The dough is then granulated and the doughy granules about 100.mu. to 500.mu. in major dimension are used for filling tube elctrodes of a lead-acid storage battery.

Granulated lead oxides with teflon

An improvement in the production of plate type electrodes for use in lead storage batteries from a dry lead powder mixture is disclosed. The lead powder is mixed with a small amount (0.1 to 3 weight percent) of polytetrafluoroethylene (PTFE) powder, the mixture is heated and treated to convert substantially all of the PTFE into fibrous form. The mixture is applied to an electrode grid under conditions whereby a coherent, unitary structure is formed. A hot liquid (e.g., water) may be added to the mixture to form a paste.

Method for the production of electrodes for lead storage batteries

An improvement in the preparation of dry lead powder mixtures for the production of tube electrodes for lead storage batteries to reduce the dust binding problem during filling of the tube electrodes is disclosed. A small amount (0.1 to 3 weight percent) of polytetrafluoroethylene (PTFE) is mixed with the lead powder, the mixture is heated and shear stresses are applied thereto sufficient to convert substantially all of the PTFE in the mixture to fibrous form. The resulting mixture can be utilized in a dry powder process for the filling of tube electrodes with a substantial reduction or elimination of the dust binding problem.

Production of lead powder for tube electrodes

Greater uniformity of particle size and free-running properties are achieved in the production of granular material for lead storage battery electrodes by adding water or sulfuric acid to a mixture of granules of lead and lead oxide to produce a paste which is pressed through a foraminous body such as a filter cloth and the resulting granules dried by permitting free fall through a heated gaseous drying medium. Novel apparatus for carrying out the process is also disclosed.

Growing community of inventors

Nol, Sweden

Ove Nilsson