JPH08190914A - Electrode plate for battery - Google Patents

Abstract

PURPOSE: To increase charge/discharge characteristic by forming working parts in a flat surface part of a current collector, three-dimensionally standing the working parts in the thickness direction from the current collector flat surface, and forming the height of the three-dimensionally worked parts in a plurality of dimensions. CONSTITUTION: A working part 2 is three-dimensionally stood in a hook shape in the thickness direction from a current collector flat surface to form a three-dimensional working part 2', and the working parts 2' in different lines are formed so as to have different height to make three-dimensional in the different dimension up and down. A frame comprising a protruded part having almost the same height as the working part 2' is formed in the surroundings of an aggregate of the working parts 2', and an active material is strongly held with the working part 2' and the frame. The working parts 2 in which the width of a continuous part 3 is 1.5mm and length is 2mm are formed at intervals of 3mm in length and width and right and left, and the working parts 2 are three-dimensionally worked with a rotary mold in an L-shaped hook shape so that an upper part and a lower part are mutually formed every a line. By existence of the three-dimensional worked part, current collecting efficiency to an active material in the position far from the current collector flat surface is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a battery electrode plate, and more particularly to an improvement in retention of active material and collection of current.

[0002]

2. Description of the Related Art Regardless of whether it is a primary battery or a secondary battery, the electrode plate for a battery is often applied or filled in a conductive current collector in the form of a paste or a slurry of an active material and other constituent materials.

It is required for these current collectors to secure a filling amount per area and to have high current collecting characteristics, and it is an important factor that they can be stably maintained for a long period of time.

In particular, in a lead-acid battery using a paste type electrode plate, the life is remarkably shortened due to the decrease in the binding force between the active materials and between the active material and the current collector due to repeated charging and discharging,
There is a demand for new current collectors that can hold active materials stably over a long period of time and have excellent current collection characteristics.

[0005]

However, in the conventional lead-acid battery, the expanded grid or punching metal substrate has been used as a current collector.

In the expanded lattice body, the active material filled inside the lattice is not supported by the lattice body particularly in the lattice body having a large opening, so that the active material is easily dropped from the lattice body during charging and discharging.

Further, in the punching metal substrate, the current collecting efficiency of the discharge reaction of the active material located at a position far from the substrate in the thickness direction in the active material layer coated on the substrate is not good, and the holding power of the active material is not sufficient. There was also a problem in terms.

Further, it has been proposed to provide a burr around the perforated portion of the punching substrate to enhance the current collecting efficiency and the active material holding force, but it could not be sufficiently improved only by the burr portion.

The present invention is intended to solve these problems, and enhances the ability of an active material to be retained on a flat current collector, and a charge / discharge reaction of an active material existing at a position away from the flat surface of the current collector. The present invention provides a battery electrode plate capable of improving the current collection efficiency.

[0010]

In order to solve the above problems, the battery electrode plate of the present invention uses, as a current collector, a flat plate current collector having a large number of three-dimensional processed portions on its surface. The three-dimensional processed portion is three-dimensionalized in the thickness direction from the current collector plane, and different three-dimensional processed portions have different heights.

[0011]

In this structure, the flat portion of the current collector is formed with the cut portion which is cut into a predetermined shape, and the cut portion is three-dimensionally formed from the flat surface of the current collector in the thickness direction. Since the height of the active material layer is a plurality of types having different heights, the active material layer arranged on the current collector can be firmly held by the three-dimensionally processed portion so as not to slip.

The high-level three-dimensionally processed portion can enhance the holding property and current collecting property of the active material layer near the surface of the electrode plate.

Further, since the low-level three-dimensionally processed portion is present in the active material layer in a tightly packed state, the distance between the active material and the current collector existing below the intermediate portion of the active material layer is lower than that in the prior art. It can be shortened and the current collection efficiency of the discharge reaction of the entire active material can be improved to improve the charge / discharge characteristics of the battery.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 show how the current collector for a battery of the present invention is manufactured. In FIGS. 1 (A) and (B), 1 is a flat plate-shaped current collector, 2 is a U-shaped cut-out processed part, and 3 is a continuous part continuous with the current collector flat part. is there. Then, as shown in FIG.
Is three-dimensionally shaped like a hook from the plane of the current collector in the thickness direction to form a three-dimensional processed portion 2 '. Here, the three-dimensionally processed portions 2'of different examples are three-dimensionalized in different directions vertically with a difference in height. Further, a small hole 4 is provided in the three-dimensional processed portion.

3 and 4 show another example of the current collector shown in FIG. As shown in FIG. 3, in this current collector, a frame portion 5 composed of a convex portion having a height approximately equal to the height of the three-dimensionally processed portion 2'is formed around the aggregate, and As shown in (3), the active material can be more strongly held by the three-dimensional processed portion 2'and the frame portion 5.

Next, the current collector shown in FIG. 1 was produced as follows. First, lead-calcium with a thickness of 0.18 mm
A flat plate made of tin alloy was prepared.

Next, U-shaped processed portions 2 having a width of the continuous portion 3 of 1.5 mm and a length of 2 mm were formed at intervals of 3 mm vertically and horizontally. Then, the processing part 2 was three-dimensionally processed into an L-shaped hook shape by a rotary mold so that the processing parts 2 were alternately alternated row by row. At this time, the height of the L-shaped three-dimensionally processed portion was 0.9 mm for the row A and 0.3 mm for the row B. The size of the small holes was 0.3 mm in diameter. Next, the current collector was filled with an existing paste containing lead powder, sulfuric acid, and water as main components and then cut to obtain an electrode plate having a filling amount of 75 g and an area of 100 cm ² . This electrode plate was referred to as electrode plate A.

An electrode plate similar to that described above was prepared except that an expanded grid was used as the current collector, and this was used as electrode plate B.

Next, using these electrode plates A and B, JIS
A battery corresponding to 48B26 of 1301 was prepared, and a life test was performed as batteries A and B by repeatedly discharging at a current of 1 hour at a temperature of 60 ° C. to 1.75 V per cell and charging for 2 hours. FIG. 5 shows the result of the life test.

As can be seen from the figure, in the battery A, the hook-shaped three-dimensional processed portions having different heights can improve the active material holding ability and the current collecting property from the upper part to the lower part of the active material layer, and the small three-dimensional processed portion can be used. Since it has a hole,
The electrical conductivity of the front and back surfaces of the current collector was further improved, and the cycle life characteristics were improved compared to Battery B.

The three-dimensional processed portion may have a trapezoidal shape, a hemispherical shape, a mountain shape, a corrugated shape, or the like, instead of being formed into a three-dimensional shape by forming a hook shape or a step shape.

[0023]

As described above, in the present invention, the flat plate-shaped current collector is provided with the three-dimensional processed portion, and this three-dimensional processed portion is three-dimensionalized in the thickness direction from the plane of the current collector. By the presence of the above, it is possible to improve the current collecting efficiency for the active material existing at the position away from the current collector flat portion, and it is possible to improve the charge / discharge characteristics of the battery. In addition, since the height of the three-dimensionally processed portion is set to multiple types, the active material existing from the upper part to the lower part of the active material layer can be strongly retained, and the active material is prevented from falling off from the electrode plate, resulting in a long life. A battery can be provided.

Further, by providing a small hole in the three-dimensionally processed portion, the holding power of the active material and the current collecting characteristic of the electrode plate can be further improved.

[Brief description of drawings]

FIG. 1A is a plan view showing a state of a current collector for an electrode plate of the present invention at the time of production. FIG.

FIG. 2A is a plan view of a current collector for an electrode plate of the present invention. FIG.

FIG. 3 is a plan view showing another example of the current collector for an electrode plate of the present invention.

FIG. 4 is a side sectional view of the current collector.

FIG. 5 is a diagram showing charge / discharge cycle life characteristics of a battery.

[Explanation of symbols]

 1 flat plate current collector 2 processed part 2'three-dimensional processed part 3 continuous part 4 small hole 5 frame part

Claims (3)

[Claims] 1. A three-dimensionally processed flat plate current collector, comprising a flat plate-shaped current collector having a large number of three-dimensionally processed parts on its surface and an active material layer provided on at least one surface of the current collector. Part of the part is continuous with the current collector flat part, and the other part is notched into a predetermined shape, and this processed part is three-dimensionalized from the current collector plane in the thickness direction of the current collector. In addition, the height of the three-dimensional processed part is different and the electrode plate for the battery is made up of multiple types. 2. The electrode plate for a battery according to claim 1, further comprising a frame body portion around the three-dimensionally processed portion, the frame portion having a convex portion having a height substantially equal to the height of the three-dimensionally processed portion. 3. The electrode plate for a battery according to claim 1, wherein the three-dimensionally processed portion is three-dimensionalized upward or / and downward.