JP2000021450A - Pressure reducing device for polymer battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas pressure reducing device capable of providing mass production of polymer battery, having high reliability while miniaturizing the device and reducing the weight thereof. SOLUTION: This pressure reducing device has a drilling tool 4, which has a tip to be inserted into a gas accumulation part 2" of a polymer battery for opening, a first forward and backward moving mechanism 5 for causing the drilling tool 4 to move forwards and backwards with respect to the gas accumulation part 2", an elastic body 7 for pushing the gas accumulation part 2" opened by the drilling tool 4 to discharge the gas, and a second forward and backward moving mechanism 8 for causing the elastic body 7 to more forwards and backwards with respect to the gas accumulation part 2".

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure reducing device for a polymer battery, and more particularly, to a gas pressure reducing device generated and sealed in a process of manufacturing a flat polymer battery.

[0002]

2. Description of the Related Art For example, secondary batteries such as non-aqueous solvent batteries are widely used as power sources for portable telephones and video cameras. In the power supply battery,
With the miniaturization and high performance of the above-mentioned devices, miniaturization, weight reduction, high voltage, high capacity, and the like are required. In response to such demands, for example, polymer batteries having a thickness of about 1 mm are known (Japanese Patent Application Laid-Open Nos.
225765, etc.).

[0003] That is, as shown in a sectional view of a main part configuration in Fig. 2, a battery element part 1 is positioned and accommodated and mounted in a resin film bag (exterior covering) 2 having one end opened. On the other hand, after the required electrolytic solution is injected, the opening is heat-welded and hermetically sealed. here,
The battery element section 1 includes a sheet-like positive electrode layer 1a and a sheet-like negative electrode layer 1b facing each other, a sheet-like polymer-electrolyte system 1c airtightly interposed and arranged between these two electrode layers 1a and 1b, A current collector sheet (not shown) electrically connected to the layers 1a and 1b, respectively, and a positive electrode terminal and a negative electrode terminal extend from the outer cover 2 so as to be separated from the positive electrode and negative electrode current collectors (not shown), respectively. Has been issued (derived). The sheet-like positive electrode layer 1a is formed mainly of a lithium-containing metal oxide (for example, lithium-manganese composite oxide, lithium-containing cobalt oxide) or a manganese dioxide that occludes and releases lithium ions. Further, the sheet-shaped negative electrode layer 1b is formed of a lithium metal or a carbonaceous material that occludes / releases lithium and a lithium alloy system, and further, the polymer-electrolyte system 1c is used as a separator base made of a polypropylene nonwoven fabric or the like. , An ethylene carbonate solution such as a lithium salt, which is impregnated or supported by a non-aqueous electrolyte.

[0004]

The flat-type polymer secondary battery of this type is not only capable of achieving a higher capacity but also lighter in weight than a lead-acid battery or a nickel-cadmium secondary battery. However, the following inconveniences are recognized. That is, in the above-mentioned polymer secondary battery, hydrogen gas is generated in the electrode layers 1a and 1b at the time of the first charging in the manufacturing process, which causes the battery to be enlarged or the internal pressure of the battery to rise. May cause. FIG. 3 is a perspective view schematically showing a state of the polymer battery in which a gas reservoir is generated by the generation of the hydrogen gas.

In FIG. 3, reference numeral 2 denotes an exterior cover, 2 'denotes a fusion / sealing portion of the exterior cover 2, 2' denotes a generated gas reservoir, and 3a and 3b denote positive and negative lead terminals.

Therefore, after the initial charge, the process of evacuating and reducing the pressure of hydrogen gas in the resin film-made outer cover 2, transferring the hydrogen gas to another process line, laminating again with a resin film, and hermetically sealing is employed. Attempts have also been made. However, performing the step of exhausting and depressurizing gas from the inside of the battery and the step of hermetic sealing by relamination separately not only deteriorates workability but also increases the space for manufacturing equipment. is there.

[0007] In order to solve such a practical problem, as a relatively simple means, a thin tube having a sharp end is inserted into a gas reservoir 2 "in an outer sheath 2 of a polymer battery, and the other end is connected to a vacuum system. In other words, a method of exhausting and reducing the pressure is known.In other words, the outer cover 2 is made larger with respect to the battery element portion 1, and one end side in the outer cover 2 is used as a gas reservoir 2 ″. Exhaust gas from this gas reservoir 2 ″
After depressurization, a means for producing a polymer battery by sealing the outer cover 2 by heat welding inside the portion (for example, AA line in FIG. 3) inside the place (exhaust opening) into which the thin tube is inserted is known. ing. However, according to this method, the insertion position of the sharp tip of the thin tube becomes delicate due to the state of the gas reservoir 2 ″, which impairs mass productivity, and the vacuum system sucks and removes the electrolyte in addition to the exhaust. As a result, the performance of the polymer secondary battery varies, the yield decreases, and the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a gas pressure reducing device capable of mass-producing a highly reliable polymer battery in addition to reducing the size and weight. .

[0009]

According to the first aspect of the present invention, there is provided a piercing tool which is opened by inserting a tip into a gas reservoir of a polymer battery, and a first advance / retreat for moving the piercing tool back and forth with respect to the gas reservoir. A mechanism, an elastic body that suppresses a gas reservoir portion opened by the piercing device and releases accumulated gas, and a second advance / retreat mechanism that advances / retreats the elastic body with respect to the gas reservoir portion. This is a pressure reducing device for a polymer battery.

According to a second aspect of the present invention, in the polymer battery decompression device according to the first aspect, the piercing tool is a cutter blade.

According to a third aspect of the present invention, in the pressure reducing device for a polymer battery according to the first or second aspect, the elastic body is made of urethane rubber.

According to a fourth aspect of the present invention, in the pressure reducing apparatus for a polymer battery according to any one of the first to third aspects,
At least one of the first moving mechanism and the second moving mechanism is a cylinder.

That is, the invention according to the first to fourth aspects of the present invention is characterized in that the outer cover is set to be relatively large with respect to the battery element portion, and the one end side of the outer cover is accumulated with the generated gas. This is an apparatus related to exhaustion and decompression of generated gas in the process of manufacturing a polymer battery in which the gas reservoir is evacuated and depressurized, and then the outer cover is thermally welded and sealed inside the exhaust opening.

In other words, the means for evacuating and reducing the accumulated gas of the polymer battery are formed in two stages, and an exhaust opening is formed in the gas accumulation section, and then the gas accumulation section is continuously formed with an elastic body. The main point is to suppress and release the accumulated gas entirely. Further, by the configuration and combination of the continuous means, the operation of evacuating and reducing the pressure in the gas reservoir is improved, the productivity is improved, and the apparatus is made more compact.

In the invention of claims 1 to 4,
The piercing device is appropriately selected, such as a thin rod-like needle or a cutter blade, depending on the size, shape, enormous state, thickness of the outer covering layer, etc. of the gas reservoir generated in the polymer battery. That is, there is no particular limitation as long as the tip is sharp enough to insert or cut the thickness of the outer covering layer and can form a minimum opening through which accumulated gas can be exhausted. A cutter blade is preferable because of its simplicity.

Further, the opened gas reservoir is suppressed,
An elastic body is selected as the suppressor for extruding and releasing the accumulated gas, in order to avoid mechanical damage and adverse effects on battery performance to at least the outer covering layer, more preferably the polymer battery including the electrode element portion. Here, examples of the elastic body include rubbers and plastics, and urethane rubber is preferable.

Further, as a reciprocating mechanism for respectively reciprocating the piercing tool such as the cutter blade and the elastic body, an air cylinder, an oil cylinder and the like can be mentioned.
These two reciprocating mechanisms can also be configured to be interlocked, and when they are interlocked, productivity can be further improved.

In the invention of claims 1 to 4,
The target polymer battery is, for example, a positive electrode obtained by laminating a positive electrode layer containing an active material such as a metal oxide, a nonaqueous electrolyte and an electrolyte-retaining polymer on a current collector, and an active material that occludes and releases lithium ions. A negative electrode formed by laminating a negative electrode layer containing a non-aqueous electrolyte and an electrolyte-retaining polymer on a current collector;
Lamination via an electrolyte-retaining polymer-electrolyte system that functions as a separator (for example, a system such as a polymer such as hexafluoropropylene-vinylidene fluoride copolymer and an ethylene carbonate solution such as a lithium salt, a nonaqueous electrolyte). The outer surface (rear surface) of the positive electrode and the negative electrode is covered and protected by, for example, a polyimide resin sealing sheet (bag).

As the active material of the positive electrode, for example, lithium manganese composite oxide, manganese dioxide, lithium-containing cobalt oxide, lithium-containing nickel cobalt oxide, amorphous vanadium pentoxide containing lithium, chalcogen compound, etc. No. Examples of the negative electrode active material include fired products of bisphenol resin, polyacrylonitrile, cellulose, and the like, fired products of coke and pitch, and these are natural or artificial graphite, carbon black, acetylene black, ketjen black, nickel powder, and the like. And a form containing nickel powder or the like.

Further, the electrolyte system may be prepared by adding lithium perchlorate, lithium hexafluorophosphate, boron tetrafluoride to a non-aqueous solvent such as ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate. Examples thereof include those in which lithium chloride, lithium arsenic hexafluoride, lithium trifluoromethanesulfonate, and the like are dissolved at about 0.2 to 2 mol / l. In addition, as the current collector of the positive electrode,
For example, aluminum foil, aluminum mesh, aluminum extract band metal, aluminum punch metal, etc. are mentioned.
Examples thereof include a copper mesh, a copper band metal, a copper punch metal, and the like.

According to the first to fourth aspects of the present invention, in the manufacturing process of the polymer battery, the gas in the opening of the gas reservoir and the gas generated and built therein can be easily and reliably reduced. That is, the gas can be evacuated and depressurized in a continuous operation and process, but the operation is not complicated, so that the gas is evacuated and depressurized efficiently. In addition, gas exhaust
Since the pressure reduction is performed without any variation or the like, it greatly contributes to the production of a highly reliable and high quality polymer battery with a good yield.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIG.

FIG. 1 is a vinegar perspective view showing a main part of a polymer battery decompression device according to an embodiment. In FIG. 1, reference numeral 4 denotes a piercing tool which is opened by inserting its tip into the gas reservoir 2 "of the polymer battery 2, for example, a cutter blade. Reference numeral 5 denotes a first blade which advances and retreats the cutter blade 4 with respect to the gas reservoir 2". It is an advance / retreat mechanism. The cutter blade 4 has, for example, a width of about 9 mm, a thickness of about 0.4 mm, and a tip part having an inclination of about 30 °. The other end is fixedly supported by a support member 6. Then, the support member 6 is connected to a first advance / retreat mechanism 5, for example, an air cylinder.
With this, it is configured to advance and retreat in a certain direction.

Reference numeral 7 denotes an elastic member for suppressing the gas reservoir 2 "of the polymer battery 2 opened by the cutter blade 4 and discharging the accumulated gas. Reference numeral 8 denotes an elastic member for the gas reservoir 2". Is a second forward / backward mechanism for moving forward / backward. Here, the elastic body 7 is, for example, a urethane rubber plate having a thickness of about 15 mm, and is fixed and held by the holding member 9. And
The holding member 9 is connected to a second reciprocating mechanism 8, for example, an air cylinder, and is configured to reciprocate in a certain direction by the air cylinder 8.

A first reciprocating mechanism 5 for reciprocating the cutter blade 4 and a second reciprocating mechanism 8 for reciprocating the elastic body 7 are provided.
Are displaced so that the forward and backward functions of the forward and backward mechanisms 5 and 8 do not interfere with each other. That is, with respect to the advance and retreat of the cutter blade 4 opening the gas reservoir 2 ″ of the polymer battery 2, the elastic body 7 is depressed by moving from the opening of the gas reservoir 2 ″ of the polymer battery 2 to suppress the gas accumulated in the opening. It is set and arranged in such a positional relationship that it is easy to release and exhaust.

Next, the operation of the pressure reducing device will be described.

A polymer secondary battery in which hydrogen gas generated during the initial charging process is sealed and a gas reservoir 2 ″ is formed on one end side of the outer cover 2 is set on a base surface (not shown). Then, the cutter blade 4 is aligned with one end of the gas reservoir 2 "of the polymer secondary battery. Then the first
By operating the reciprocating mechanism 5, the tip of the cutter blade 4 is inserted and cut into the exterior covering of the gas reservoir 2 "to form an exhaustable opening. 1
While the cutter blade 4 is retracted by the reciprocating mechanism 5, the gas accumulating portion 2 ″ is suppressed by the elastic member 7 by the operation of the second reciprocating mechanism 8, and the accumulated gas is pushed out and exhausted from the formed opening. After the release and exhaust of the gas in the gas reservoir 2 ″, the elastic body 7 is retracted by the second advance / retreat mechanism 8.

Here, the time required for exhausting and depressurizing the gas reservoir 2 ″ is at most about 2 seconds, which is significantly higher than the conventional gas exhausting means in terms of reliability, reliability, and productivity. In addition, a highly reliable polymer battery can be easily and mass-produced by the above-described steps and procedures while being a compact device. The battery is heat-sealed again with the exterior coverings 2 inside the gas reservoir 2 ″ to seal the battery element 1 liquid-tight or air-tight, and then cut off the gas reservoir 2 ″. It becomes a polymer secondary battery product.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, the piercing tool may be a needle / rod instead of a cutter blade,
It is also possible to adopt a configuration in which the gas reservoir after the depressurization is cut off and welding sealing means is provided.

[0030]

According to the first to fourth aspects of the present invention, the formation of the exhaust port, and the exhaust and decompression are performed in a continuous process. That is, not only can the operation be complicated, but also the generation and accumulation of gas can be discharged or reduced in pressure with good reproducibility, so that a highly reliable and high-quality polymer battery can be manufactured at a high yield. .

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a main configuration of a pressure reducing device for a polymer battery according to an embodiment.

FIG. 2 is a perspective view showing a configuration example of a main part of a polymer battery.

FIG. 3 is a perspective view schematically showing a state of the polymer battery in which a gas reservoir has occurred.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electrode element part 1a ... Positive electrode layer 1b ... Negative electrode layer 1c ... Polymer-electrolyte system 2 ... Outer coating 2 '... Welding sealing part of outer coating 2' ... Gas reservoir 3a, 3b Terminal 4 Drilling tool 5 First retreat mechanism 7 Elastic body 8 Second retreat mechanism

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H012 AA03 BB00 CC01 FF02 JJ06 5H029 AJ12 AJ14 AK02 AK03 AK05 AL06 AL07 AM03 AM07 BJ04 BJ21 BJ27 CJ04 CJ30 DJ01 DJ11 EJ12

Claims (4)

[Claims] 1. A piercing tool that inserts a tip into a gas reservoir of a polymer battery to open it, a first advance / retreat mechanism for moving the piercing tool toward and away from the gas reservoir, and a gas opened by the piercing tool. A pressure reducing device for a polymer battery, comprising: an elastic body that suppresses a pool to release a stored gas; and a second advance / retreat mechanism that moves the elastic body back and forth with respect to the gas pool. 2. The pressure reducing device for a polymer battery according to claim 1, wherein the punch is a cutter blade. 3. The pressure reducing device for a polymer battery according to claim 1, wherein the elastic body is urethane rubber. 4. The pressure reducing device for a polymer battery according to claim 1, wherein at least one of the first moving mechanism and the second moving mechanism is a cylinder.