JP2012033305A - Manganese dry cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manganese dry cell having excellent discharge performance.SOLUTION: A positive electrode mixture 1 is contained in a bottomed cylindrical negative electrode zinc can 4 via a separator 3, a carbon rod 2 pressure inserted in the vicinity of the center of the positive electrode mixture 1 is fitted to the inside of a substantially columnar protrusion of a positive electrode terminal 11 and brought into electrical contact therewith. Since an n-regular prismatic carbon rod 2 is employed in such a manganese dry cell, occupied area of the carbon rod in the cell can be reduced as compared with that of a conventional columnar carbon rod, and thereby more active material can be filled correspondingly.

Description

  The present invention relates to a manganese dry battery, and more particularly to a connection between a positive electrode terminal of a manganese dry battery and a positive electrode current collector.

  Conventionally, the connection between the positive electrode terminal and the positive electrode current collector in this type of battery is made near the center of the positive electrode mixture using manganese dioxide housed in a bottomed cylindrical negative electrode zinc can through a separator as an active material. Generally, a cylindrical carbon rod (corresponding to a positive electrode current collector) is press-fitted, and the periphery of the end face is fitted inside a substantially cylindrical protrusion of the positive electrode terminal to take out electricity to the outside. . (See Patent Document 1).

Japanese Utility Model Publication No. 54-5029

  From the viewpoint of increasing the capacity of the battery, it is preferable that the carbon rod is as thin as possible within a range where the current collecting effect can be secured. However, the diameter of the carbon rod has heretofore been determined by the diameter of the protruding portion of the positive electrode terminal.

  This is because the minimum value of the diameter of the projecting portion of the positive electrode terminal is determined by the JIS standard or the IEC standard, and the diameter of the carbon rod fitted inside is naturally determined. For example, in the single type, the minimum value of the diameter of the protruding portion of the positive electrode terminal is 7.8 mm, and when the thickness of the positive electrode terminal is 0.2 mm, the diameter of the carbon rod is set to about 7.4 mm or more. It will be.

  That is, it is difficult to make the carbon rods thinner and to fill more active materials.

  In order to solve the above-mentioned object, the present invention accommodates a positive electrode mixture through a separator in a bottomed cylindrical negative electrode zinc can, and a carbon rod press-fitted in the vicinity of the center of the positive electrode mixture. A manganese dry battery fitted inside and electrically in contact with a cylindrical protrusion, wherein the carbon rod has a regular n prism shape.

  According to the present invention, it is possible to reduce the volume as compared with the conventional cylindrical carbon rod, and accordingly, more active material can be filled, and the discharge performance is improved. is there.

The front view which made a part of manganese dry battery of the present invention a section Sectional drawing which expanded between AA 'in FIG.

  According to the present invention, a positive electrode mixture is housed in a bottomed cylindrical negative electrode zinc can through a separator, and a carbon rod press-fitted near the center of the positive electrode mixture is inserted into a substantially cylindrical projection of the positive electrode terminal. The battery is a manganese dry battery that is fitted inside and electrically contacted with the inside of the battery. By making the carbon rod into a regular n-prism shape, the occupied volume in the battery can be reduced as compared with a conventional cylindrical carbon rod. As a result, more active material can be filled, and the discharge performance can be improved.

  The portions corresponding to the n sides of the side surface of the regular n prismatic carbon rod are fitted into and in electrical contact with the substantially cylindrical protrusion of the positive terminal. And it becomes possible to fill a positive electrode mixture into a part corresponding to between each side.

  It should be noted that the portion corresponding to the n sides of the side surface does not necessarily need to form a geometrically strict corner, and may be, for example, a chamfered shape in an arc shape.

  Specifically, the regular n prismatic carbon rod may have n in the range of 3 to 8, and preferably n in the range of 5 to 7. More preferably, the carbon rod may have a regular hexagonal prism shape.

  Examples of the present invention will be described in detail below, but the present invention is not limited to the examples shown below.

  The AA manganese dry battery (R6) shown in FIG. 1 was produced by the following procedure. FIG. 1 is a front view, partly in section, of an AA manganese dry battery as one embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view taken along the line AA ′ in FIG.

  A piece of zinc alloy containing 0.01% by mass of lead, 0.0025% by mass of indium and 0.05% by mass of manganese was pressed to produce a cylindrical negative electrode zinc can 4 having an opening at one end.

  The positive electrode mixture 1 was accommodated in the negative electrode zinc can 4 through a separator 3 and a bottom paper 13 described later.

  The separator 3 was a kraft paper coated with a paste obtained by dispersing a cross-linked starch and a binder mainly composed of vinyl acetate in water and dried. At this time, the separator 3 was disposed so that the surface on which the paste material was applied was opposed to the negative electrode zinc can 4.

  The bottom paper 13 was formed by punching out 0.3 mm thick kraft paper into a circular shape and then squeezing it into a cup shape inside the separator 3.

  The positive electrode mixture 1 includes electrolytic manganese dioxide as an active material, acetylene black as a conductive material, an electrolytic solution containing 30% by mass of zinc chloride, 2% by mass of ammonium chloride, and 68% by mass of water, and zinc oxide as an additive. Was mixed in a mass ratio of 52.3: 8.7: 38.5: 0.5 (corresponding to an increase of about 2% with respect to the conventional example described later). And the carbon rod 2 obtained by sintering carbon powder was inserted in the center part of the positive electrode mixture 1. The carbon rod 2 used was a 47 mm long hexagonal prism whose cross section is a regular hexagon having a diagonal length of 4.0 mm.

  A hole for press-fitting the carbon rod 2 was provided at the center of the sealing body 5 made of polyethylene. Holes for inserting the carbon rods 2 were also provided in the paper 9 obtained by punching out the kraft paper in an annular shape. The carbon rods 2 were inserted into the holes of the paper 9 and the sealing body 5, respectively, and these were arranged on the upper part of the positive electrode mixture 1.

  The outer periphery of the negative electrode zinc can 4 was covered with a resin tube 8 made of a heat-shrinkable resin film for ensuring insulation. At that time, the upper surface of the resin tube 8 covered the upper surface of the outer periphery of the sealing body 5. Further, at the lower end portion, the negative electrode terminal 6 and a seal ring 7 are arranged on the outer surface side of the flat plate outer peripheral portion to cover the lower surface of the seal ring 7.

  The positive electrode terminal 11 was obtained by pressing a tin plate having a thickness of 0.2 mm into a predetermined shape. This was fitted on the end face of the carbon rod 2 to electrically connect the positive electrode terminal 11 and the carbon rod 2.

  An insulating ring 12 made of resin is disposed on the flat collar portion of the positive electrode terminal 11.

  A metal outer can 10 made of a cylindrical tin plate is placed outside the resin tube 8, its lower end is bent inward, its upper end is curled inward, and its tip is insulated. The battery was obtained by caulking the ring 12.

(Conventional example)
An AA manganese dry battery (R6) similar to the example was manufactured except that the diameter of the carbon rod 2 was 4.0 mm and the filling amount of the positive electrode mixture 1 was 8.9 g.

  Next, the evaluation and results of each battery obtained above will be described. As an evaluation of the discharge performance, a time required to reach 0.9 V was measured under a 20 ± 2 ° C. environment by applying a load of 3.9Ω per cell (load corresponding to a toy or a motor). The average value of five batteries for each battery was 94 minutes for the conventional battery and 98 minutes for the battery of the example.

  From the above results, it is clear that the batteries of the examples according to the present invention have excellent discharge performance.

  Although the AA type has been described in the above-described embodiments, the present invention can of course be applied to other types (single 1, single 2, single 4, single 5).

  Since the manganese dry battery of the present invention is excellent in discharge performance, it can be suitably used for any device that uses a dry battery as a power source.

DESCRIPTION OF SYMBOLS 1 Positive electrode mixture 2 Carbon rod 3 Separator 4 Negative electrode zinc can 5 Sealing body 6 Negative electrode terminal 7 Seal ring 8 Resin tube 9 Paperboard 10 Metal exterior can 11 Positive electrode terminal 12 Insulation ring 13 Bottom paper

Claims (4)

  The positive electrode mixture is housed inside the bottomed cylindrical negative electrode zinc can through a separator, and the carbon rod press-fitted near the center of the positive electrode mixture is fitted inside the substantially cylindrical protrusion of the positive electrode terminal. A manganese dry battery brought into electrical contact, wherein the carbon rod has a regular n prism shape.   2. The manganese dry battery according to claim 1, wherein n is in the range of 3 to 8 in the regular n-prism carbon rod.   2. The manganese dry battery according to claim 1, wherein n is in a range of 5 to 7 in the carbon rod having a regular n-prism shape.   The manganese dry battery according to claim 1, wherein the carbon rod has a regular hexagonal prism shape.

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