JPS6050855A - Manufacturing method for flat batteries - Google Patents

Abstract

PURPOSE:To surely avoid outside short circuit and improve productivity by reinforcing sealing performance by heat-depositing a heat deposited portion again after sealing up an electric battery chamber which accommodates generating elements by preliminary heat deposition and cutting it to the predetermined shape, and by extending seal material on an external circumferential portion of a seal body. CONSTITUTION:In a long sheet 10 sealing as seal material, cutting windows are provided at a constant interval. And the sheet is heat-deposited at a window frame portion, a positive pole container plate 8 and a negative pole container plate 5. And space surrounded by the side wall of a cutting window portion of the seal material 10 and the positive pole container plate 8 and the negative pole container plate 5 forms an individual electric battery chamber, and in each electric chamber, a positive pole black mix layer 9, a separator 7 and a negative pole 6 are contained and non-aqueous electrolytic liquid are enclosed. Next, each of the electric battery chambers that lie in a row is cut in an individual electric battery chamber unit. And in the seal body obtained in this way, a positive pole container 8, a negative pole container 5 and the seal material 10' are incorporated in an electric battery for the first time as single parts. The seal portion of this seal body is further subjected to pressurization and heating, and deposition characteristics are strengthened, and at the same time, a part of the seal material 10' melted or softened at the time of deposition is extended between an external circumferential portion and a guide jig, and the guide jig is removed, thereby an electric battery is made.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a thermoplastic resin sealing material processed into a window frame shape is interposed at the periphery of a pair of opposing battery container pieces, and the periphery of the container pieces is The surface and sealing material are bonded by heat welding,
This invention relates to a method for manufacturing a flat battery in which a battery chamber containing a power generation element is formed.

Conventional Structure and Problems Therein, a flat battery as shown in FIG. 1 has been proposed as one of the conventional examples of batteries having this type of structure. In Figure 1, 1
2 is a metal plate positive electrode container that also serves as a negative electrode terminal, 3 is a window frame-shaped sealing material made of thermoplastic resin, and the three are adhered by heat welding. A power generation element 4 is housed inside. This battery has problems in its handling, such as the fact that it is easy for the conductor to accidentally touch the outer periphery of the battery, and the battery is frequently consumed due to external short circuits during handling.

Therefore, in order to solve this problem, a method has been adopted in which the outer periphery is insulated using a resin mortar or the like, and for example, a battery as shown in FIG. 2 has been proposed. That is, negative electrode container 1
' is processed into a dish shape, and a sealing material 3' is molded and integrated in advance so that the sealing material 3' covers the periphery and outer circumference of the negative electrode container 1'.

A positive electrode container 2 similar to that shown in FIG. 1 is thermally welded to this sealing material 3' to form a battery chamber, in which a power generation element is housed.

According to this configuration, there is no fear of an external short circuit even if a conductor touches the outer periphery of the battery, and it is effective from the viewpoint of battery functionality only, but there is a big problem in mass productivity of the battery. In other words, in order to increase the productivity of such flat, thin batteries, for example, thin layers of positive and negative electrodes or separators of a predetermined shape are coated at predetermined intervals on a long foil-like thin material for the positive and negative electrode containers. The sealing material is formed continuously by methods such as adhesion or pressure bonding, and the sealing material is also formed by forming cut windows of a predetermined shape at predetermined intervals on a long sheet.
A continuous production system is suitable, in which each of these long elements is overlapped and successively heat-welded, and finally punched out using a press or the like to complete the construction of the battery.For example, as shown in Figure 1, This production method can be adopted for batteries. However, in the case of the battery shown in Figure 2, it is necessary to mold the sealant into one of the battery containers in advance as a component, so the configuration of each battery must be done individually, and the former Compared to the continuous production method, the disadvantage was that the production efficiency was much lower.

Special WA1190-50855 (2) Object of the Invention The object of the present invention is to provide a method for manufacturing a flat battery that can reliably prevent external short circuits at the outer periphery and has high productivity.

Structure of the Invention The present invention provides a thermoplastic resin sealing material processed into a window frame shape between a pair of opposing battery container plates, and a power generation element is placed in a battery chamber formed by thermally welding the container plate and the sealing material. In the method for manufacturing a flat battery containing a power generating element, the battery chamber containing the power generation element is sealed by preliminary heat welding, the sealed body is cut into a predetermined shape, and the heat welded portion is then further heat welded. In addition to strengthening the sealing performance by providing
The present invention is characterized in that a sealing material is extended to the outer peripheral portion of the sealing body by the heat welding.

According to the present invention, a battery having a function equivalent to the external short circuit prevention function explained in FIG. 2 of the conventional example is produced by a highly productive manufacturing method similar to the continuous production method similar to the battery in FIG. 1. Obtainable.

Explanation of the Example, Figure 3 shows a state in which each power generation element is housed in each battery chamber, each battery chamber is sealed by preliminary heat welding, and the battery chambers are connected with each other separated by sealing material. In the sketch, Figure 4 is A.
-A/ line sectional view. Figure 3.

In FIG. 4, 6 is a negative electrode container plate made of a long stainless steel foil, 6 is a negative electrode lithium crimped to a predetermined location on the container plate 6 at a predetermined interval, and 7 is a negative electrode lithium crimped and fixed to the negative electrode 6. This is a separator made of polypropylene nonwoven fabric. 8
9 is a positive electrode container plate made of a long stainless steel foil, and 9 is a paste prepared by adding and kneading an aqueous dispersion of manganese dioxide, acetylene black, fluororesin, and a gel solution of carboxyl methyl cellulose at predetermined locations on the container plate 8 at predetermined intervals. The positive electrode mixture layer is coated, dried, and rolled. 10 is a long sheet of sealing material copolymerized by adding maleic anhydride to polyethylene, and cut windows are provided at regular intervals, and the sheet is thermally welded to the window frame, the positive electrode container plate 8, and the negative electrode container plate 6. A space surrounded by the side wall of the cut window of the sealing material 10 and the positive electrode container plate 8 and negative electrode container plate 6 forms an independent 6-page battery chamber, and each battery chamber has a positive electrode mixture layer 9° and a separator 7. , a negative electrode 6 is housed, and a non-aqueous electrolyte in which lithium perchlorate is dissolved in propylene carbonate is sealed.

Next, FIG. 6 is a cross-sectional view of each battery chamber in the state shown in FIG. 4, cut into individual battery chambers.
1 shows a cross section of the sealed body obtained by cutting parts 1 and B'. In other words, it corresponds to the cross section of the battery explained in FIG. 1 of the conventional example, and the positive electrode container 8', the negative electrode container 6', and the sealing material 10' are assembled into the battery as a single component for the first time in this process. becomes. Fig. 6 shows that the sealing part of the sealing body shown in Fig. 6 is further pressurized and heated to strengthen the welding property, and a part of the sealing material 10' that was melted or softened during welding is placed between the outer peripheral part and the guide jig. The battery is shown with the guide jig removed and the battery extended.The outer periphery of the battery is protected by the extended part of the sealing material, so even if a conductor touches the outer periphery, there will be no external short circuit. The structure is such that it does not

Note that depending on the design of the guide jig, the outer peripheral seam 714-
] The extending shape of the glue material can be changed as appropriate, and if it is simply extended as shown in FIG. 7, no particular guide jig is required. In order to prevent external short circuits, the state shown in Figure 7 is practically sufficient in many cases, but to be sure, it is better to protect the end faces of the positive electrode container 8' and negative electrode container 6' as shown in Figure 6. This further increases reliability.

Effects of the Invention As described above, the present invention is extremely effective in effectively preventing external short circuits in flat batteries and improving productivity.

[Brief explanation of drawings]

1 and 2 are vertical cross-sectional views of a conventional battery, and FIG. 3 is a sketch of an embodiment of the present invention in which each battery chamber is sealed by preliminary heat welding and is connected to another. Figure 4 is a cross-sectional view of a part of it, Figure 5 is a cross-sectional view of the series of battery chambers in Figure 4 cut into individual battery chambers, and Figures 6 and 7 are the sealed body of Figure 5. FIG. 3 is a cross-sectional view of a battery according to an embodiment in which the sealing portion of the battery is further heat-sealed and the sealing material is extended to the outer peripheral portion. JP-A-Sho GO-50855 (3) 1 6...Negative electrode container plate, 6'...Negative electrode container, 6...Negative electrode lithium, 7...Separator , 8... Positive electrode container plate, 8<... Positive electrode container, 9... Positive electrode mixture layer, 10... Seal material. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure? Figure 2 f' Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] A flat battery in which a thermoplastic resin sealing material processed into a window frame shape is interposed between a pair of opposing battery container plates, and a power generating element is housed in a battery chamber formed by thermal welding of the battery container plates and the sealing material. In this manufacturing method, a battery chamber containing a power generating element is sealed by preliminary heat welding, and then a sealed body is cut into a predetermined shape, and then the preliminary heat welded seal part is further sealed. A method for manufacturing a flat battery, characterized in that a step of heat welding is provided to extend a sealing material to an outer peripheral portion of the sealed body.