JPH04171657A - Separator for lead-acid battery and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve the life of a lead-acid battery by folding and stacking unweldable porous body layers at the inside, pressing them from above, pinching at least part of projections, and connecting thermoplastic resin porous body layers together. CONSTITUTION:An unweldable porous body layer 1 with an angular irregular shape 3 on both side sections is stacked on a thermoplastic resin porous body layer 2 so that the upper and lower sections of the folding line CL in the perpendicular direction to both sides are made vertically symmetrical, and they are folded at the folding line CL so that the unweldable porous body layer 1 is located inside. They are inserted between a pair of engagedly rotated gears and pressed by the tip pressures of the teeth of gears corresponding to the pitch of the gears. Thermoplastic resin porous body layers 2, 12 are welded together at connection layers 3, 31 while projections provided on both side sections of the unweldable porous body layers 1, 11 are pinched, and a bag- shaped separator arranged with the unweldable porous body layers 1, 11 inside and the thermoplastic resin porous body layers 2, 12 outside is formed. The life of a lead-acid battery is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a separator for lead-acid batteries and a method for manufacturing the same, and particularly relates to a separator in the form of a mat made of glass fiber as a main component and a separator in the form of a sheet made of polyethylene as the main component. This article relates to a bag-shaped separator made of silk and a method for manufacturing the same.

Conventional technology (lr) Since then, a flat separator has been used in which a separator mainly composed of glass fiber for the purpose of retaining the active material and a separator mainly composed of pulp etc. have been bonded together. Productivity problems were caused by misalignment of the separator, and short circuits occurred at the bottom of the electrode plates due to softening and falling off of the active material, which led to the end of its life.As an improvement, the main component was polyethylene, which is a porous thermoplastic resin. By converting the sheet-like separator into a bag-like separator using heat welding, ultrasonic welding, adhesion, etc., short circuits at the bottom due to active material falling off and production problems have been improved.However, it is still relatively slow. During a lifetime that involves deep charging and discharging, the active material cannot be held down sufficiently, causing the active material to fall off and end its life.In addition, the positive electrode plate may curve,
Due to deformation, the separator could be punctured and short-circuited.

For this reason, it became necessary to use a separator mainly made of glass fiber to hold the active material on the electrode plate side in combination with a bag-shaped sheet separator. To do this, it was necessary to weld these matte porous layers, which are mainly composed of glass fibers, which are non-weldable materials, facing each other, but this posed problems in terms of productivity and cost.

The problem that the invention aims to solve is to make it possible to industrially perform bag-forming welding and partial welding that maintains shape even when a non-weldable porous body is placed on the electrode plate side, and as a result, realize a configuration with excellent service life. The challenge was to do so. Conventionally, the only way to join a separator mainly composed of glass fiber as a non-weldable porous body and a separator mainly composed of polyethylene as a thermoplastic resin porous body was to use adhesive. The reason for this is that the materials suitable for these mat bodies are generally non-weldable porous materials in most cases, and although thermoplastic separators are welded, common methods such as thermal welding, simple pressure, ultrasonic welding, high frequency welding, etc. It has been thought that this method of welding thermoplastic resin separators is impossible. The present invention solves these problems, and aims to provide a separator for lead-acid batteries and a method for manufacturing the separator that can extend the life of lead-acid batteries.

Means for Solving the Problem In order to solve this problem, the lead-acid battery separator of the present invention and the method for manufacturing the same are provided by forming an uneven shape on both sides so that the upper and lower sides of the fold line perpendicular to the both sides are symmetrical. The provided non-weldable porous layer is stacked on the thermoplastic resin porous layer, folded along the crease line so that the weldable porous layer is located on the inside, and then pressurized to form the non-welded layer. This is a separator for a lead-acid battery in which the convex portions on both sides of the thermoplastic resin porous layer are sandwiched, and the thermoplastic resin porous layers are bonded to each other.

In addition, the non-weldable porous material layer having an uneven shape on both sides is stacked on the thermoplastic resin porous material layer so that the upper and lower sides of the crease line in the direction perpendicular to the both sides are symmetrical. The non-weldable porous material layer is folded and stacked so that it is located on the inside, and is inserted between a pair of gears that rotate while meshing with each other. Pressure is applied to bond the thermoplastic resin porous layers to each other, and the thermoplastic resin is permeated from the thermoplastic resin porous layer into the non-weldable porous layer to bond the non-weldable porous layer and the thermoplastic resin porous layer. The present invention provides a method for manufacturing a separator for lead-acid batteries that joins porous thermoplastic resin layers.

Effect With this configuration, the separator for lead-acid batteries and the method for manufacturing the same of the present invention provide uneven shapes on both sides of the non-weldable porous layer,
A non-weldable porous material layer is stacked on a thermoplastic resin porous material layer, the non-weldable porous material layer is folded so that it is located on the inside, and pressure is applied from above, thereby at least a portion of the convex portion is removed. The porous thermoplastic resin layers are bonded together by sandwiching them.

= 6- Example Hereinafter, a separator for a lead-acid battery according to an example of the present invention and a method for manufacturing the same will be described with reference to the drawings.

Figure 1 is an example of a developed view of the separator structure, where 1 is a matte non-weldable porous layer mainly composed of glass fiber, and 2 is a sheet-like porous thermoplastic resin layer mainly composed of polyethylene. be. Crease line CL perpendicular to both sides
- Square uneven shape 3 on both sides so that the bottom is symmetrical
A non-weldable porous material layer 1 provided with a thermoplastic resin porous material layer 2
Lay them on top of each other, bend them along the crease line CL so that the non-weldable porous material layer 1 is located on the inside, insert this between a pair of gears that rotate while meshing with each other, and insert the teeth of the gears that correspond to the bits of the gears. Pressure was applied using the tip pressure to form a separator as shown in FIG. 4 is a pressurized area; 4. a is a bonding layer.

Let this separator be A. FIG. 2 is another example of a developed view of the separator structure, except that a non-weldable porous layer 11 is used, which is provided with a wave-like uneven shape 13 on both sides so that the top and bottom are symmetrical along the fold line C. The configuration is similar to that shown in FIG. 1
2 is a thermoplastic resin porous layer. FIG. 4 is similar to the configuration shown in FIG. 3, with reference numeral 14 indicating a pressure region and 14a a bonding layer.

This separator is designated as B.

As a result, as shown in FIG. 3 for separator A, and as shown in FIG. 4 for separator B, the bonding layer 3
, 13, the thermoplastic resin porous layers 2 and 12 are welded by sandwiching the convex portions provided on both sides of the non-weldable porous bodies 1 and 11, and the non-weldable porous layers 1 and 11 are heated inside. A bag-shaped separator can be constructed in which the porous plastic resin layer 2.12 is disposed on the outside.

The separator thus created was placed on the positive electrode and combined with the negative electrode to assemble a battery equivalent to 48Ah.The battery created using the separator A was designated as A', and the battery created using the seven-layer separator B was designated as B'. For comparison, a battery equivalent to 48 Ah was fabricated by using a plate-shaped separator in which a separator mainly composed of glass fiber and a separator mainly composed of pulp were bonded together with an adhesive, and the positive and negative electrodes were tied together. Let this be C'. Figure 5 is based on a test method called the JIS life test, which is a deep charge/discharge pattern at 60°.
C, charge at 5A for 5 hours, discharge at 20A for 1 hour, 2
5 cycles were repeated, the terminal voltage was increased by 20△ every 251 no-cycles], and continuous discharge was performed until the terminal voltage reached 0.2V. , B', and C' are the results of evaluating the batteries. The horizontal axis represents the life index when the number of lifetimes of the battery C' is set to 1.00, and the vertical axis represents the capacity at 20 A discharge. The lifetimes of A' and B' were almost the same, and each was about 50% longer than C'. Also, for batteries A' and B',
No peeling of the separator weld was observed during the life of the separator.

Note that the same effect can be obtained even if the uneven portion has an irregular shape. In this example, the maximum width of the non-weldable porous material layer provided with the uneven portions was the same as that of the thermoplastic resin porous material layer, but although not shown, some of the protruding portions were It is clear that the same effect can be obtained if the pressure is applied to the welded part and the pressure is sandwiched between the parts.

In the configuration of this embodiment, in the portions where the non-weldable porous layers face each other, the thermoplastic resin permeates through the non-weldable porous layers and welds them together under special pressurized conditions, thereby enhancing the bonding strength. Furthermore, this configuration can be easily achieved without any adhesive, and it is possible to weld a non-weldable porous layer such as a mat made of 100% glass fiber, which is necessary for longevity, or to weld a mat made of a mixture of polyethylene and glass fiber. It is suitable for use in attached buildings and is highly effective in improving lifespan.

Effects of the Invention As is clear from the description of the embodiments above, according to the separator for lead-acid batteries and the manufacturing method thereof of the present invention, non-weldable porous bodies and thermoplastic resin porous bodies, which were previously thought to be impossible, can be easily produced. It is now possible to weld the separator to the sheet-like separator, making it easy to install it together with a sheet-like separator, which has an extremely large effect on improving the lifespan of lead-acid batteries.

[Brief explanation of the drawing]

Fig. 1 is a developed view of a separator for a lead-acid battery according to an embodiment of the present invention and a method for manufacturing the same, Fig. 2 is a developed view of a separator in an embodiment of the present invention, and Fig. 3 is a developed view of a separator according to an embodiment of the present invention.
Front view showing the completed state of the separator shown in Figure 4.
The figure is a front view showing the completed state of the separator shown in Figure 2, and Figure 5 is a 60°C life test based on the JIS life test of batteries manufactured using an embodiment of the present invention and a conventional separator for lead-acid batteries. 3 is a graph showing the life test results of . 1.11...Non-weldable porous layer, 2,12...
...Porous thermoplastic resin layer, 3...Irregular shape. Name of agent: Patent attorney Haruaki Koba and 2 others Q: 6\t

Claims (6)

[Claims] (1) A non-weldable porous material layer having an uneven shape on both sides is stacked on the thermoplastic resin porous material layer so that the upper and lower sides of the crease line perpendicular to the both sides are symmetrical, and The non-weldable porous material layer is folded along a line so that the non-weldable porous material layer is located on the inside, and the layers are pressed together to sandwich the convex portions on both sides of the non-weldable porous material layer, and the thermoplastic resin porous material is A separator for lead-acid batteries with layers bonded together. (2) Claim 1 in which the convex portions provided on both sides of the non-weldable porous layer have joint surfaces bonded by a thermoplastic resin that allows the non-weldable porous layer to pass through the thermoplastic resin porous layer.
Separator for lead-acid batteries as described. (3) The separator for a lead-acid battery according to claim 1 or 2, wherein the separator is a bag-shaped separator that covers either the positive electrode or the negative electrode. (4) The separator for a lead-acid battery according to claim 1, 2 or 3, wherein the non-weldable porous layer is a mat-like separator containing glass fiber as a main component. (5) The separator for a lead-acid battery according to claim 1, wherein the porous thermoplastic resin layer is a sheet-like separator containing polyethylene as a main component. (6) A non-weldable porous material layer having an uneven shape on both sides is stacked on the thermoplastic resin porous material layer so that the upper and lower sides of the crease line perpendicular to the both sides are symmetrical, and The non-weldable porous material layer is folded along a line so that the non-weldable porous material layer is located on the inside, and the layer is folded and stacked, and this is inserted between a pair of gears that rotate while meshing with each other, and the pressure at the tip of the tooth of the gear corresponding to the pitch of the gear is applied. Pressure is applied to join the thermoplastic resin porous layers to each other, and at the same time, the thermoplastic resin is permeated from the thermoplastic resin porous layer into the non-weldable porous layer to form a bond with the non-weldable porous layer. A method for manufacturing a separator for a lead-acid battery that joins the porous thermoplastic resin layer.