Abstract: An alkaline electrolyte secondary electric cell comprises at least one positive electrode and one negative electrode positioned on either side of a separator composed of polyolefin fibers grafted with a vinyl monomer. The cell contains a device for absorbing and retaining nitrogen in a strongly basic medium, with a pH of at least 12. This device is constituted by the separator.

Abstract: The present invention relates to a non-sintered nickel electrode for a secondary cell having an alkaline electrolyte. The electrode has a current collector and a paste comprising a powder active material based on nickel hydroxide, a conductive material containing lithium and cobalt, and a binder. The active material is made up of particles of a hydroxide containing a majority of nickel that is at least partially oxidized into a &bgr; structure oxyhydroxide, said particles being at least partially coated in lithiated oxide of nickel and cobalt.

Abstract: An alkaline electrolyte secondary electric cell comprises at least one positive electrode and one negative electrode positioned either side of a separator composed of polyolefin fibers grafted with a vinyl monomer. The cell contains a device for absorbing and retaining nitrogen in a strongly basic medium, with a pH of at least 12. This device is constituted by the separator. A vinyl monomer solution is forced into the pores of the separator by drawing the solution through the separator, for example by using a suction pump.

Abstract: A negative electrode for an alkaline electrochemical cell. The electrode comprises an active material and a hydrophilic agent constituted by small cylindrical rods of polyolefin provided with hydrophilic groups. The mean length of the rods is less than 50 microns and the mean diameter thereof is less than 20 microns. A method of manufacturing a negative electrode in which hydrophilic rods are made by fragmenting long polyolefin fibers having a mean diameter of less than 20 microns by oxidizing them, with the rods being mixed with the active material and the mixture being applied to a current conductor.

Abstract: A spirally wound storage cell having an alkaline electrolyte, the storage cell being in particular of the nickel-cadmium type or of the nickel metal hydride type, and including at least one positive electrode and at least one negative electrode on either side of a non-woven separator made up of fibers made exclusively of polypropylene, said storage cell being characterized by the fact that said separator (5) comprises first and second superposed layers, said first layer (6) being obtained by the "spun-bond" method and serving as a support, and said second layer (7) being obtained by needling fibers on said first layer, the needling tangling the fibers of the second layer together, and bonding them to the fibers of the first layer.

Abstract: The present invention concerns a nickel electrode comprising a nickel-based hydroxide which satisfies at least one of the following criteria:an intensity ratio of the ?103! line to the ?200! line in the X-ray diffraction diagram of 1.05.+-.0.10;a coherence length L of 13.+-.3 nm,a ratio of the sum of the surface areas of the peaks at 3687.+-.10 cm.sup.-1 and 3600.+-.10 cm.sup.-1 to the surface area of the peak at 3580.+-.10 cm.sup.-1 of the Raman spectrum of 0.11.+-.0.03;a ratio of the surface area of the peak at 511.+-.10 cm.sup.-1 to the surface area of the peak at 460.+-.10 cm.sup.-1 in the Raman spectrum of 1.1.+-.0.1.