Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/04—Cells with aqueous electrolyte

Definitions

• Dry battery having a cathode with additives
• the present invention relates to a dry battery of the primary alkaline type. More particularly, the invention relates to a battery including a zinc anode, an anodic gel containing an alkaline compound, and a cathode including a depolarizing mixture based on manganese dioxide and graphite.
• the object of the present invention is a further increase - by means of particular additives - of the output of the battery, expressed as the duration of discharge before the discharge tension falls below a preset level.
• the present invention provides for the use as additive of a mica powder whose grains have a surface at least partially coated with titanium dioxide, this powder having a particle size distribution of between 1 and 100 micrometres, preferably between 1 and 15 micrometres.
• the said powder has a content by weight formed from equal parts of titanium dioxide and mica.
• Said powder can be present in the depolarizing mixture forming the cathode in a percentage quantity of between 0.1 and 5%, preferably in a percentage quantity of the order of 1%.
• the titanium dioxide contained in the said powder can be present in any one of its allotropic forms called anatase, rutile and brookite, also in a mixture of these, and is deposited on the mica grains, for example by dispersing the mica in liquid titanium tetrachloride and then transforming, by means of a known thermochemical process, the titanium tetrachloride into titanium oxide of the desired allotropic form.
• the particular structure of the additive proposed according to the present invention characterized by a high granulometric fineness and, given the particular lamellar configuration of the mica crystals, by a high value of the surface-to-volume ratio of the grains themselves and by surface adhesion of the titanium dioxide particles to the mica particles - provides an increased absorption capacity for liquids and hence electrolyte on the part of the cathodic mass in which the additive is dispersed.
• the absorption capacity of the electrolyte increases by about 8% when passing from an additive composed solely of titanium dioxide to an additive as described above and composed of mica and titanium dioxide in equal parts.
• the increased quantity of electrolyte contained in the cathode makes higher discharge outputs possible, both for discharges at high consumption and for other types of use.
• Figures 1 to 6 show graphs of the discharge of batteries with an additive, respectively, with an additive containing 95% of rutile, the tests for which are marked A in the graphs, and with an additive containing 50% of rutile and 50% of mica mixed with one another in a powder, the tests for which are marked E in the graphs.
• batteries were prepared comprising: a zinc anode, an anodic gel containing caustic potash, a corrosion inhibitor without added mercury, and a cathode comprising a depolarizing mixture based on manganese dioxide, graphite and the mica powder in which the grains were coated with rutile.
• a depolarizing mixture said components were intimately mixed with one another beforehand in order to ensure a homogeneous distribution in the mixture.
• the same constructional criterion was used and the same common components were utilized in order to guarantee the maximum uniformity of the batteries themselves which were produced from a single batch of common materials.
• the test was carried out with a uniform criterion also with regard to the ageing of the batteries or to the time elapsed from the formation of each battery and the test itself. In all the tests, the concentration of the additive was kept within 1% relative to the manganese dioxide.
• the values of duration measured show that the batteries of type E (provided with an additive of mica and rutile) give durations which are greater by a value of between 4% and 8% than the durations of the batteries of type A (provided solely with a rutile additive) .

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Battery Electrode And Active Subsutance (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11351385

Family Applications (1)

Country Status (2)

Cited By (8)

Citations (3)

• 1995
  • 1995-10-03 IT IT95FI000203A patent/IT1278764B1/it active IP Right Grant
• 1996
  • 1996-09-30 WO PCT/IT1996/000181 patent/WO1997013285A1/en active Application Filing

Patent Citations (3)

Non-Patent Citations (1)

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