JPH08250102A - Manufacture of square battery - Google Patents

Abstract

PURPOSE: To prevent the damage of a separator with a simple method, and prevent a short-circuited state from being caused in a case inner part. CONSTITUTION: A plurality of positive electrodes 5, negative electrodes 6 and separators 7 are laminated, and current collecting positive electrode leads 8 drawn from the respective positive electrodes 5 and current collecting negative electrode leads 9 drawn from the respective negative electrodes 6 are bundled and connected in parallel to each other, respectively. The current collecting positive electrode leads 8 and the current collecting negative electrode leads 9 are bundled and connected in parallel in positions where they are substantially coincident with each other in the laminating direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a structure in which a plurality of positive electrodes, negative electrodes and separators are laminated and the current collecting positive electrode lead of each positive electrode and the current collecting negative electrode lead of each negative electrode are connected in parallel. The present invention relates to a method of manufacturing a prismatic battery configured.

[0002]

2. Description of the Related Art A prismatic battery used as a power source for a portable device such as a portable telephone or a portable personal computer is constructed, for example, as shown in FIG. The prismatic battery shown in FIG. 2 has a case 1 that opens upward and forms a negative electrode terminal, a lid 2 that has an electrolyte injection port 2a and a safety valve 2b that seals the opening of the case 1, and a lid 2 that is arranged on the lid 2. The positive electrode terminal 3 provided, a long lead 4 having one end connected to the positive electrode terminal 3, a plurality of stacked positive electrode electrodes 5, negative electrode electrodes 6, and separators 7.
And a current collecting positive electrode lead 8 that is drawn from each positive electrode 5 and connected in parallel to each other and connected to the other end of the lead 4.
A negative electrode lead 9 for current collection, which is drawn out from each negative electrode 6 and connected in parallel to each other and connected to the case;
It is composed of an electrolyte solution filled inside.

Conventionally, the manufacturing method for manufacturing the prismatic battery having the above-described structure is as follows: the negative electrode 6, the separator 7, the positive electrode 5, the separator 7, the negative electrode 6, ... The electrodes 5 and the negative electrodes 6 are alternately laminated, and then the current collecting positive electrode leads 8 extracted from the respective positive electrode electrodes 5 are bundled and connected in parallel by a resistance welding machine or the like, and the negative electrode electrodes 6 are extracted. Negative electrode lead 9
Bundled together and connected in parallel with a resistance welding machine, etc., and then case 1
The electrode portions laminated as described above are housed therein, the current-collecting negative electrode lead 9 connected in parallel is connected to the inner surface of the case 1, and the current-collecting positive electrode lead 8 connected in parallel is It includes a step of connecting to the positive electrode terminal 3 provided on the lid 2 via a long lead 4.

[0004]

However, it is often found that a short-circuit state occurs in the electrode portion in the above-mentioned bundling and wiring steps, and the inventors of the present invention have made a careful investigation and found that Lead 8 and negative electrode lead 8 for current collection
It has been discovered that the short-circuit state is concentrated and occurs when the bundling position in the stacking direction is greatly deviated.

Then, considering the cause, the thinning of the separator 7 (instead of the conventional thick non-woven fabric having a thickness of about 0.2 mm, a thickness of 20 to 30 μm) has been demanded in order to improve the battery capacity and discharge current. A thin PP or PE porous film or the like has come to be used.), And the positive electrode 5 and the negative electrode 6 are made thinner (instead of the conventional thick one having a thickness of about 1 mm, a thickness of 0). ., A thin-walled one having a thickness of about 1 to 0.2 mm has been adopted.), And the number of laminated positive electrodes 5 and negative electrodes 6 has increased (the conventional number of positive electrodes 5 is as small as about 2 to 3). 1 instead of the negative electrode 6
As many as 0 sheets of the positive electrode 5 and the negative electrode 6 have been adopted. ), Interference between the bundled current collecting positive electrode leads 8 and between the bundled current collecting negative electrode leads 9 and damage to the separator 7 are likely to occur, and as shown in FIG.
If the collecting positions of the current collecting positive electrode lead 8 and the current collecting negative electrode lead 9 are largely displaced in the stacking direction, the separator 7
It was found that there is a part in which the direction of copying the current is reversed between the side of the current collecting positive electrode lead 8 and the side of the current collecting negative electrode lead 9, and the separator 7 is damaged in the vicinity of the reversal and a short circuit state occurs.

The present invention has been made based on the above consideration, and an object of the present invention is to provide a method for manufacturing a prismatic battery capable of preventing damage to the separator and preventing a short circuit condition by a simple method. To do.

[0007]

According to a first aspect of the present invention, a plurality of positive electrode electrodes, a negative electrode and a separator are laminated, and a current collecting positive electrode lead is drawn from each of the positive electrodes, and each of the positive electrodes. A method for manufacturing a prismatic battery, in which current collecting negative electrode leads drawn from a negative electrode are bundled and connected in parallel, wherein the plurality of current collecting positive electrode leads and the plurality of current collecting negative electrode leads are laminated in a stacking direction. The method for manufacturing a prismatic battery is characterized in that the cells are bundled at substantially the same positions and connected in parallel.

[0008]

According to the method for manufacturing a prismatic battery of the first aspect of the present invention, a plurality of current collecting positive electrode leads and a plurality of current collecting negative electrode leads are bundled at positions substantially coincident with each other in the stacking direction and connected in parallel. Thus, the tracing direction of the separator is the same on the side of the positive electrode lead for current collection and on the side of the negative electrode lead for current collection, so that the separator is not damaged and a short circuit state does not occur.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the method for manufacturing a prismatic battery according to this embodiment, first, a plurality of positive electrode electrodes 5, negative electrode electrodes 6 and separators 7 are formed into a negative electrode electrode 6, a separator 7, a positive electrode electrode 5, a separator 7 and a negative electrode electrode 6. The steps of forming electrode parts by stacking so as to form an array of ... Here, each of the positive electrode 5, the negative electrode 6, and the separator 7 is made of, for example, lithium cobalt oxide, carbon, and a polyethylene porous film, which are power generation elements of a lithium battery, and the positive electrode 5 is made of an aluminum foil current collector. The positive electrode lead 8 for electricity is taken out as an integral part or a separate body from the positive electrode 5, and the negative electrode lead 9 for current collection made of copper foil is pulled out as an integral part or a separate body from the negative electrode 6 from the negative electrode 6. Has been.

Next, as shown in FIG. 1, a plurality of current collecting positive electrode leads 8 and a plurality of current collecting negative electrode leads 9 are bundled at positions substantially coincident with each other in the stacking direction, and a resistance welding machine or ultrasonic welding is performed. Using a machine or the like, the bundled current collecting negative electrode leads 9 are connected in parallel, and the bundled current collecting positive electrode leads 8 are connected in parallel and at the same time connected to one end of a long lead 4 (for example, a lead made of aluminum). To do.

Next, the electrode portion is housed in a case 1 formed by molding a nickel-plated steel plate or stainless steel, and the negative electrode lead 9 for current collection connected in parallel and the case 1 are connected by a resistance welding machine or the like.

Next, the other end of the long lead 4 and the positive electrode terminal 3 made of nickel-plated steel plate arranged on the lid are connected by a resistance welding machine or an ultrasonic welding machine.

Next, the case 1 is sealed with a lid 2, and an electrolytic solution is injected into the case 1 through an electrolytic solution injection port 2a. The electrolytic solution injection port 2a is made of a SUS plate having a thickness of about 0.1 to 2 mm. Or N
i Plate is sealed by welding with YAG laser.

As described above, in the present embodiment, when the collecting positive electrode lead 8 and the collecting negative electrode lead 9 are bundled and connected, as shown in FIG. The lead 8 and the plurality of current collecting negative electrode leads 9 are bundled at positions substantially coincident with each other in the stacking direction and connected in parallel. Therefore, the tracing direction of the separator 7 is the same on the side of the current collecting positive electrode lead 8 and the side of the current collecting negative electrode lead 9,
The separator 7 is not damaged and the short-circuit state does not occur. Although FIG. 1 shows the position on the left end side of the drawing as the bundling position, damage to the separator 7 can be prevented at other positions, such as the position on the right end side of the drawing and the central position, which are substantially coincident with each other in the stacking direction.

When the bundling position of the current collecting positive electrode lead 8 and the bundling position of the current collecting negative electrode lead 9 are opposite to each other (see FIG. 3), the internal short circuit defect rate is 8%. On the other hand, when the bundling position of the current collecting positive electrode lead 8 and the bundling position of the current collecting negative electrode lead 9 are made to coincide with each other as in this embodiment (corresponding to FIG. 1), the internal short circuit failure rate is It was verified that it would be 0%.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining main steps of a method for manufacturing a prismatic battery according to an embodiment.

2 is a configuration diagram of a prismatic battery manufactured by a conventional manufacturing method, FIG. 2 (A) is a front partial cross-sectional view, and FIG. 2 (B).
Is a left side partial sectional view, and FIG. 2 (C) is a right side partial sectional view.

FIG. 3 is an explanatory diagram for explaining the problems of the above conventional method.

[Explanation of symbols]

 5 Positive electrode 6 Negative electrode 7 Separator 8 Positive electrode lead for current collection 9 Negative electrode lead for current collection

Claims (1)

[Claims] 1. A positive electrode lead for collecting current drawn from each of the positive electrode while stacking a plurality of positive electrode, negative electrode and separator, and a current collecting lead drawn from each of the negative electrode. In a method for manufacturing a prismatic battery, in which negative electrode leads are bundled and connected in parallel, the plurality of current collecting positive electrode leads and the plurality of current collecting negative electrode leads are bundled and arranged in parallel at positions substantially parallel to each other. A method for manufacturing a prismatic battery, which comprises connecting wires.