S.c.p.s. Societe De Conseil Et De Prospective Scientifique, S.a.

Sorapec S.a.

S.c.p.s.

S.c.p.s. Societe De Coneil Et De Prospective Scientifique S.a.

Robert Rouget

Bernard Bugnet

Denis Doniat

Guy Bronoel

Noelle Tassin

Thierry Potier

Fabrice Fourgeot

Jacques Doniat

Silver positive electrode for alkali secondary batteries having an enhanced cycling capability, and consequently a longer lifetime in cycling of the storage batteries incorporating it, by optimizing, in recharge mode, the conditions for electrochemically reducing the oxidized silver species. The silver electrode according to the invention is of the plasticized type, and a high-porosity collector, such as a woven fabric, a felt or a reticulated cellular metal foam, is used. The active compound introduced into the collector is prepared in paste form, in which the active material consists of metallic silver particles and/or silver monoxide particles, and may advantageously include a metal oxide acting as pore-forming and wetting agent for the electrode. Such an electrode is particularly intended for mounting in silver-zinc storage batteries operating in open mode or sealed mode.

Silver positive electrode for alkaline storage batteries

The invention concerns a device for catalytic recombination of gases for alkaline batteries with shortened zinc anode. The invention concerns a device for catalytic recombination of gases formed when charging a zinc anode alkaline battery, characterized in that it consists of a catalytic mass in contact with a crosslinked cellular metal foam serving as catalyst support and heat dissipating structure, said catalytic mass consisting of a mixture of carbon black including metal of platinum metals, and of a hydrophobic binder, the whole assembly being heat-treated to cause the hydrophobic binder of said catalytic mass to be sintered. Said device is advantageously connected to one of the terminals of the battery or to any other metal part constituting part of the cover of the battery case, so as to promote discharge of the calories produced. Such a device enables, in a long lasting manner during the charge-discharge cycles, limited internal pressure levels to be maintained, in particular in installations designed to operate without maintenance.

Device for catalytic recombination of gases for alkaline batteries with shortened zinc anode

The invention relates to an additive to the active mass of a zinc anode for an alkaline secondary electrochemical generator. Said additive contains conductive ceramic powder, preferably titanium nitride particles which is exposed to an oxidation pre-treatment prior to the incorporation thereof into the active mass of the anode. Said ceramic powder is used as electronic conduction in the anode active mass and as zincates retention which are produced by generator discharge. In order to use said retentive capacity, the powder is exposed to an oxidation pre-treatment, whereby making it possible to form the binding sites on the surface of ceramic grains. The inventive additive makes it possible, starting from the first cycles of the electrode formation, to form uniform zinc deposits, thereby increasing the service life for the cycling of the zinc anode.

Ceramic conductor pre-treated by oxidising for a zinc anode

The invention relates to secondary alkaline electrochemical generators with a zinc anode in an electrolyte, the active mass of said anode comprising at least one conductive ceramic. According to the invention, the electrolyte of the generator is made up of a highly-concentrated alkaline solution and/or the active mass of the zinc anode contains an additive comprising at least one alkaline titanate having general formula (MO)(Ti))xHO, wherein M denotes Li, Na, K, Rb or Cs, n being between 0.5 and 2, m being between 1 and 10 and x being between 0 and 10, or alkaline earth having general formula (MO)(TiO)xHO, wherein M denotes Mg, Ca, Sr or Ba, n being between 1 and 5, m being between 1 and 10 and x being between 0 and 10. The invention also relates to the zinc anode of the generators used in the invention and the production method thereof.

Alkaline secondary electrochemical generators with a zinc anode

The invention concerns the treatment of porous structures such as cross-linked foams, woven or nonwoven, to make them electrically conductive by depositing polymers. The device enables, in a chemical reactor, to perform the activating treatment directly through non-reeled off blocks or rolls of porous structures, the treating fluids of the successive steps being made to circulate inside said blocks or rolls, via a perforated rotary mandrel whereon they are pressed. Said device enables to activate efficiently the structures, which may be metal-coated or not, and are particularly designed to be used as electrodes for liquid effluent electrolysis, of detectors and traps of organic or biological molecules, electrode supports for electrochemical generators, catalyst supports, filtering media, acoustic insulants, electromagnetic, nuclear and antistatic protection structures, heat exchangers and the like.

Device for activating conductivity in porous structures

The invention relates to metallic products and a process for producing these which allows, despite the complexity of their structure, for them to be produced in refractory alloys based on chromium. The chromium is deposited by electrolysis, this being carried out by means of a bath with high throwing power. The formation of the alloy with layers of other metallic constituents is obtained by thermal diffusion. The provision of aluminum is controlled in the form of particles by immersing, by spraying or &ldquo;painting.&rdquo; The structures according to the invention are particularly intended to be used as catalyst supports or filtering agents.

High porosity three-dimensional structures in chromium based alloys

The cadmium negative electrode has a structure serving as a collector and made of nickel foam. The sponge is filled with a mixture cons mainly of cadmium oxide and contains nickel sulphate hexahydrate in the proportion of 1.8 to 2.7% by weight of the total mixture, expressed in the form of nickel.

Method of making cadmium electrodes for alkaline batteries

The cadmium negative electrode has a structure serving as a collector and made of nickel foam. The sponge is filled with a mixture consisting mainly of cadmium oxide and contains nickel sulphate in the proportion of 1.8 to 2.7% by weight of the total mixture, expressed in the form of nickel.

Cadmium electrodes for alkaline batteries

Method and apparatus for pasting a porous structure, such as a battery support plate, which provides for inserting pasty material from a vibrating hopper continuously and evenly as a sandwich filling of controlled thickness between two conveyer strips driven at the same speed to deliver pasty material with a predefined thickness and with a flat translational motion onto a substantially horizontal platen; removing the conveyor strip opposite that in contact with the platen to uncover the upper face of the pasty material; bringing the porous structure level with the platen onto the upper surface of the pasty material; pressing the pasty material into the porous structure; and removing the pasted porous structure from the lower strip. The porous structure can be simultaneously pasted on its upper side using a secondary conveyer strip.

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Paris, France

Robert Rouget