JPH11283611A - Electrochemical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate manufacture, to improve reliability and sealing performance and to increase the mechanical strength of an exterior member and energy density by providing a member different from an electrochemical element or a terminal provided in a film-like exterior member near its hole section and an exterior member closing the hole section and different from the exterior member having the hole section. SOLUTION: A circular hole 13 is provided on a negative electrode side exterior member 5, and an exterior member 17 different from the negative electrode side exterior member 5 and formed with a member 16 (angular block made of polytetrafluoroethylene) and a heat fusion layer 18 made of aluminum is provided. When the exterior member 17 is heat-fused to the negative electrode side exterior member 5, it closes the hole 13. An electrolyte is gently injected into a laminate exterior container from the portion between the member 16 and the negative electrode side exterior member 5, the exterior member 17 is arranged on the hole 13 after the injection is completed, and the hole 13 is closed by heat fusion when pressure is vertically applied and only the upper section is heated for a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electrochemical element having a novel exterior structure using a film-like exterior member at least in part, and more particularly to a flat-type electrochemical element made of a non-aqueous electrolytic solution, such as a capacitor or a battery. Further, the present invention is applied to a Li-based secondary battery, particularly a LiI-ion battery and a polymer type Li-ion battery.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. Sho 60-117542 This is a manufacturing method in which terminals of a solid electrolyte battery covered with a laminate film have a hollow structure, and a vacuum can be drawn from the terminals. However, simple sealing of a terminal having a hollow structure made of a conductive metal or the like is difficult, and the terminal tends to be thick, so that moisture or the like easily enters from the outside. 2. This is a manufacturing method in which liquid is injected by providing two ports in an outer packaging material of a thin secondary battery. However, when the vacuum injection is performed, the opening is apt to be crushed if the pressure is reduced to a certain level or more and the pressure is reduced to a certain level or less, and it takes time to achieve a sufficient vacuum, or a jig such as a thin injection nozzle is required. 3. This is a solid electrolyte battery in which the outside of a solid electrolyte battery covered with a laminate film is covered with a thermosetting resin to improve the sealing performance. At the same time, the strength can be increased, but at the same time, the flexibility of the laminated film is impaired, and at the same time, a mold is required, and mass productivity is lacking.

[0003] There is a demand for a lightweight and thin secondary battery for portable equipment or a lightweight large secondary battery for automobiles. For this purpose, as an outer container, an inexpensive, lightweight and small-sized and highly reliable as well as a simple manufacturing process are required. It is necessary to have. Conventional non-aqueous flat battery exterior containers that use a conventional laminated film-shaped heat-sealing resin as the main exterior member include a hermetically sealed structure, a terminal take-out structure, and a manufacturing process that enables it. Have been variously improved. In general, after a battery element including an electrochemical reaction element is included in a laminate film, at least a part of the periphery of the laminate film is heat-sealed for sealing.
In addition, since the terminal material has a flat exterior material and the sealing part is planar, the electrode current collector is directly applied in the direction of the flat exterior material rather than the terminal as in a single type dry battery. A structure is used in which a terminal is exposed (JP-A-57-174860), or a terminal in a sealing portion of an exterior material is sealed together and the terminal is taken out in a sealing direction (JP-A-62-61268). Can be

Further, these battery elements need to be impregnated with an electrolytic solution in a manufacturing process. In the case where the battery element is integrated with a battery element using a solid electrolyte that has been solidified or gelled in advance, the step of impregnating the battery element with the electrolyte can be omitted, but a battery having a liquid electrolyte that is not a solid electrolyte, or a solid electrolyte If an electrolytic impregnation step of the battery element is required as a solidification or gelation step or as a previous step, it is desirable to lower the water concentration of the electrolytic solution and lower the dissolved gas concentration so that it is a post-process as much as possible. Desirably, it is more preferable that the process can be performed without being exposed to the atmosphere.

In the case of a polymer battery, an electrolyte or a container containing the electrolyte may be injected. For example, an electrolyte containing a PAN-based, acrylate-based, or PVDF-based polymer dispersed after sealing a battery element. When gelling by heating after injecting the solution, or PVDF-HFP
When the battery element containing the part composed of the system polymer is sealed and then injected and gelled, or after the battery element is sealed, an electrolyte solution that dissolves the acrylate monomer and the thermal polymerization initiator is injected. After that, it may be gelled by heating. However, an exterior member using a laminated film, which is a film-like exterior member, has a large degree of freedom in shape, unlike a strong can-shaped exterior member made of iron or stainless steel or aluminum used for a normal battery. It is difficult to perform the liquid injection step after sealing because of its low strength despite the features of being easy and lightweight and thin.

For this reason, for example, Japanese Patent Application Laid-Open No. 2-139873
As shown in (2), the battery element can be easily impregnated with the electrolyte by providing two entrances and flowing the electrolyte as a process after laminating and sealing using this. However, even in this method, it is difficult to completely impregnate the electrolytic solution even in a minute portion of the electrode of the battery element, and a minute gas component remains, which inhibits the electrochemical reaction of the active material of the electrode. Not only does capacity deteriorate, but Li
In an ion battery, when the local capacity ratio of the positive electrode / negative electrode deviates from a design value, cycle deterioration is increased, or in some cases, Li is deposited on the negative electrode, and safety is significantly reduced in some cases.

[0007] In addition, a method of removing gaseous components in a battery element in advance by applying a vacuum or a reduced pressure through one port and injecting the gas component into the gas component is generally performed for a can-type battery. However, if the lamination is performed from one opening, since the strength of the laminate exterior is low, the suction opening itself is likely to be crushed due to the reduced internal pressure, and gas components often remain in the fine parts of the electrode of the battery element. Cheap. Also, when injecting, the part that is originally sealed and in close contact is swelled and the electrolyte is injected from there, so the shape of the laminate exterior is easier to swell than originally and a little more electrolyte is injected. It is difficult to control the amount of the electrolyte. Furthermore, since the inner surface of the liquid inlet is easily wetted with the electrolytic solution, the reliability of sealing at that portion is slightly reduced.

[0008] Further, in the case where the entirety of the laminate-sealed one is evacuated to the inside and outside thereof and then immersed in the electrolyte, the electrolyte is injected from the injection port provided in advance. The electrolytic solution can be impregnated into the fine parts of the electrodes of the battery element. This is a method used for a medium-sized capacitor and the like. However, as the size of the battery increases, it takes time, the waste of the electrolyte and the deterioration due to the atmosphere increase, and the cost increases. Also,
Not only the injection port but also the entire outside of the exterior member gets wet with the electrolytic solution, so that cleaning is necessary.

Further, as shown in, for example, Japanese Patent Application Laid-Open No. Sho 60-117542, there is a manufacturing method in which a terminal of a solid electrolyte battery wrapped with a laminate film has a hollow structure, and it is possible to evacuate the terminal. In this case, the liquid can be injected using this hollow structure. However, simple sealing of a terminal having a hollow structure made of a conductive metal or the like is difficult, and the terminal tends to be thick, so that moisture or the like easily enters from the outside. In addition, when the inner diameter is reduced, the injection speed is reduced. In addition, since the strength of this laminate exterior is lower than that of a can-type exterior, when other parts are provided on the laminate exterior member, the parts are easily deformed due to insufficient strength, and other parts may be deformed. The contact force had to be reduced.

In the case of a terminal as disclosed in Japanese Patent Application Laid-Open No. 57-174860, if the thickness of the terminal is increased, the sealing performance is reduced. Therefore, the terminal is mainly 200 μm or less. However, it is liable to be broken because of its weakness, and it is necessary to reduce the force required for other parts to come into contact, as in the case of the outer container. This is not desirable from the usual usage forms such as storing the battery in the pack or the equipment used, extracting electric output from the terminal, adding an electric circuit, replacing the battery, and lowers the reliability. However, the degree of freedom in designing a power supply including peripheral parts has been reduced, and it has been difficult to replace or increase the size of the power supply, thus deteriorating the use conditions. Further, since the strength of the laminate exterior is lower than that of the can type, the structure and the material of the safety valve are significantly different from those of the can type, and it is difficult to make a cut in the can itself like the can type.

Hereinafter, a conventional flat battery will be described in detail. FIG. 15A is a sectional view, and FIG. 15B is a plan view. 1 is a positive electrode current collector, 11 is a positive electrode active material layer, 2 is a negative electrode current collector, 12 is a negative electrode active material layer, 3 is a separator layer, and 4 is a positive electrode side laminate film. Reference numeral 14 denotes a positive-electrode-side heat-sealing layer coated on the positive-electrode-side laminate film 4, reference numeral 5 denotes a negative-electrode-side laminate film, and reference numeral 15 denotes a negative-electrode-side heat-sealing layer coated on the negative-electrode side laminate film 5. , 6 are positive electrode terminals, 7 is a negative electrode terminal, and these 6 and 7 are welded to the current collectors 1 and 2 respectively, and although not shown, the active material layers 11 and 12 and the separator layer 3 are not shown. The positive electrode-side heat fusion layer 14 and the negative electrode side heat fusion layer 15 are heat-sealed at both ends of the figure while sandwiching the positive electrode terminal 6 and the negative electrode terminal 7 therebetween. 8 and 9 are the positive terminal side and the negative terminal side, respectively. A void thickness of the active material layer of a certain electrode causes mainly 10 from 10A
C is a heat-sealed portion, and 10D is a non-heat-sealed portion.

In FIG. 15, the battery elements 1, 1
After sandwiching 1, 2, 12, 3, 6, and 7 between the cathode and anode-side exterior materials 4 and 5, portions 10A, B, and C are heat-sealed, and an electrolytic solution is placed in advance. It is put in a certain container, and the pressure is reduced and evacuated by sucking it, and then the electrolyte is impregnated downward with the unheated fusion part 10D as an inlet, or the inside of the container is filled with the electrolyte. By setting the inside of the container to normal pressure, it becomes possible to impregnate the battery element inside the laminate exterior with the electrolytic solution. However, as described above, this is not suitable for mass production, and the exterior of the laminate needs to be cleaned because it gets wet with the electrolytic solution, and the inner surface of the unheated fused portion 10D gets wet with the electrolytic solution. The reliability of the device decreases. Further, due to the thickness of the battery element, void portions 8 and 9 are generated, and the volume of these portions,
It is difficult to control the amount and shape of the electrolyte, and the strength is weak, and the electrolyte is easily damaged by external pressure.

[0013]

Therefore, in the present invention,
In order to solve the above-mentioned problems seen in the structure of the outer container using the conventional film-like laminate outer case, a member is provided inside the outer member, and a hole or a notch is provided in a part of the outer member and the member. An object of the present invention is to provide an electrochemical device which is easy to manufacture, has high reliability, has high sealing properties, has high mechanical strength of an exterior member, and has a high energy density.

[0014]

Hereinafter, the electrochemical device of the present invention will be specifically described with reference to the drawings. However, the electrochemical device of the present invention is not limited to the following drawings. 1. FIG. 1 is a diagram showing an embodiment (Embodiment 1) that satisfies the constitutional requirements of claim 1. Reference numeral 13 denotes a circular hole provided in the negative electrode-side exterior member 5, reference numeral 16 denotes a member (square block made of polytetrafluoroethylene), and reference numeral 17 denotes a member different from aluminum 5 having a heat sealing layer 18. The exterior member 17 has a hole 13 closed by heat sealing to 5 (the others are the same as the conventional example). Each of the positive and negative side exterior members 4 and 5 is a laminated film formed by coating a 50-micron polyethylene layer on the inner surface of a 25-micron aluminum film. In addition, the member 16 may have a flat shape, a cylindrical shape, or a polygonal pillar shape without having the illustrated shape. The material is other than polytetrafluoroethylene,
Any material can be used as long as it is resistant to the used electrolyte such as polyacetal, polypropylene, polyimide, ceramic, glass, rubber, and various metals. The surface may be roughened. However, in the case of metal, it is necessary to consider its shape and arrangement so as not to cause internal short circuit. Although the present embodiment is a stacked paper battery using one positive electrode and one negative electrode for explanation, a stacked multi-layer battery provided with several or more positive electrodes and negative electrodes may be used. In this case, the terminal, the positive electrode, and the negative electrode are used by being electrically connected to each other in advance by ultrasonic waves, spot welding, or the like.

Table 1 shows a comparison between the first embodiment and the conventional example. The results of the experiment are shown in four stages of ◎, △, Δ, and ×.
In the conventional example, another container for evacuating the entire outer container is required, so that the process tact is very long. In the present embodiment, since the vacuum is drawn from the gap between the film and the block and the liquid is injected, this is not a significant improvement, but the tact can be shortened without fail. In addition, the sealing can be easily performed in a short time because the main part can be sealed without getting wet with the electrolytic solution in the first embodiment. Furthermore, when the cycle deterioration was evaluated as reliability, there was a great difference between the conventional example and the present embodiment. This is considered to be due to an increase in moisture due to poor sealing or residual gas in the electrode active material due to poor injection. In this experiment, the evacuation was performed until the pressure reached a predetermined pressure, the injection was performed until the change in the injection amount was stopped, the sealing was performed in real time, and the cycle deterioration was 1 / 3C for 30 cycles. Measured by later capacity deterioration,
evaluated.

[0016]

[Table 1]

2. FIG. 2 is a view showing an embodiment (Embodiment 2) of a member satisfying the constitutional requirements of claim 2. (A)
And (c) are side views, and (b) and (d)
Is a plan view. In FIG. 2, reference numeral 16 denotes a square block made of polytetrafluoroethylene, which is one of (a) and (b).
Reference numeral 9 denotes a through hole provided in the rectangular block 16, and reference numerals 20 in (c) and (d) denote cutouts provided in the rectangular block 16 (others are the same as those of the conventional example or the first embodiment). By the through-holes 19, decompression and vacuuming by removing gas components,
Then, it functions as a flow path for the injection of the electrolytic solution, and can be performed in a shorter time and more reliably. Since the lower hole of the through hole is in contact with the lower laminate film, the result is similar to that of the upper case of the first embodiment, but the result is practically sufficient. It was also confirmed that the cycle deterioration was reduced and the reliability was improved, probably because the residual gas inside the electrode was reduced. Table 2 below shows the experimental results of the present embodiment when the notch is provided.

3. FIG. 3 is a view showing an embodiment (Embodiment 3) of a member satisfying the constitutional requirements of claim 3. (A)
Is a side view, (b) is a plan view, and (c) is a left side view.
Reference numeral 21 denotes a through-hole provided in the rectangular block 16, the direction of which is changed in the lateral direction (the other is the same as the conventional example or the first embodiment). The through-hole 21 serves as a flow path for decompression and vacuuming by removing gas components, and for injecting an electrolytic solution, and can be performed in a shorter time and more reliably. By arranging one of the through-holes horizontally, in Embodiment 2, evacuation and injection, which had been in contact with the lower laminate film and had been performed through the gap, were able to secure a reliable flow path. The time required for pulling was a good result. It has been confirmed that, besides the case where the hole is changed horizontally as shown in FIG. 3, changing the shape of the cutout portion is also effective. In Table 2 below,
The experimental result of this embodiment when the hole is changed laterally is shown.

4. FIG. 4 is a view showing an embodiment (Embodiment 4) of a member satisfying the constitutional requirements of claim 4. (A)
Is a plan view, (b) is a side view, and (c) is a bottom view as viewed from below. Reference numerals 22a and 22b denote through holes provided in the member (square block) 16, whose cross-sectional area is increased by slightly increasing the diameter of the holes (otherwise the same as the conventional example or the first embodiment). These through holes 22a and 2
With 2b, it can function as a flow path for pressure reduction, vacuuming, and electrolyte injection by removing gas components, and can be performed in a shorter time and more reliably. However, similar to the through hole of the embodiment, since this is in contact with the lower laminate film, a gas and liquid flow path is secured as a gap, so that the low area of the block is reduced. It is thought that there is also an effect. However, the effect of injecting liquid by increasing the same cross-sectional area was confirmed also in the case where the direction of the hole was changed in the lateral direction in the third embodiment. Table 2 below shows the experimental results of the embodiment in the case of FIG.

[5] FIG. 5 is a view showing an embodiment (Embodiment 5) of a member satisfying the constitutional requirements of claim 5. (A)
Is a plan view, (b) is a side view, and (c) is a side view. Reference numerals 23a, 23b, and 23c denote through holes provided in the rectangular block 16, which have a semicircular shape whose direction is changed in the horizontal direction and whose cross-sectional area in the horizontal direction is the same. Same as the conventional example or the first embodiment). By dividing one of the through holes horizontally and in two, the flow path can be secured in two directions, so that it is easier to realize a state in which the flow path has less resistance. This is because there are four different directions in the lateral direction: the terminal direction, the electrode direction, the sealing portion direction, and the other directions. When laminated and sealed, the laminated film itself is soft and uniform. Hard to become
It is effective to secure two directions as the flow path, because the other flow path can be ensured even if the opening of one flow path is small and closed. Further, when the two directions function, it is considered that the difference in the direction of the flow further facilitates the evacuation and the injection.
This division may be more than two divisions. Table 2 below
FIG. 5 shows the experimental results in the case of FIG. In addition to the injection, the evacuation cycle time was improved.

6. FIG. 6 is a view showing an embodiment (Embodiment 6) of a member satisfying the constitutional requirements of claim 6 and is a view seen from a side. Reference numeral 24 is a block similar to porous glass Vycor glass. The shape is 16
This is the same as the square block of polytetrafluoroethylene described above, but the material itself has minute holes, so that gas and liquid can easily flow. In addition, since there is no macro hole, the strength is high and the possibility of the closed exterior member being damaged is reduced. Table 2 below shows the experimental results in the case of FIG. In spite of not providing a large hole, the same effect as the block having the hole divided into two was confirmed. The same applies to the case where such a porous body is compounded by being embedded in the pores of a polytetrafluoroethylene block.

[0022]

[Table 2]

7. FIG. 7 is a diagram showing an embodiment (Embodiment 7) that satisfies the constitutional requirements of claim 7. A member 1 having a through hole in the lower portion of the lower surface of the upper exterior member 5 having a hole.
6 is preliminarily adhered to the lower exterior member 4, and the battery element 25 mainly composed of the positive electrode, the negative electrode, the separator, and the terminal is positioned and laminated while sandwiching the four sides. This is because the upper exterior member and the member 16
This is effective because the positioning of the two holes is not required, and the displacement of the two holes is eliminated. However, when the battery element partially overlaps, the step 16 tilts due to the step, so that it is necessary to properly position the battery element with the battery element. Table 3 below shows the positioning of the first and seventh embodiments and the subsequent tact of the lamination process in four stages. In addition, the case where the thickness of the container is increased is indicated by x, and the case where the thickness is not changed is indicated by ○.

8. FIG. 8 is a view showing an embodiment (Embodiment 8) that satisfies the constitutional requirement of Claim 8, that the exterior member having the hole or the notch and at least a part of the member are fixed. The member 16 is bonded to the battery element 25 in advance, and the four sides are sealed after positioning and laminating the member 16 while sandwiching it between the upper and lower exterior members. Since the positioning between the battery element and the member 16 is not required, it is only necessary to position the battery element with care so that there is no deviation between the two holes. By enlarging one hole, particularly the hole of the exterior member, , Can be easily positioned. However, as shown in the figure, a portion of the active material layer of the battery element where the current collector is
When the battery 6 is provided, the thickness of the battery is increased by the thickness of the member 16, so that the volume energy density is slightly reduced. However, bonding, positioning, and lamination can be easily performed. In Table 3 below, the positioning tact of the first embodiment and the eighth embodiment and the subsequent tact of the lamination process are displayed in four stages. In addition, the case where the thickness of the container is increased is indicated by x, and the case where the thickness is not changed is indicated by ○.

9. FIG. 9 is a diagram showing an embodiment (Embodiment 9) that satisfies the constitutional requirements of claim 9. (A) is a plan view, (b) is a side sectional view. An elongated member 26 is bonded in advance to a connection portion between the current collector 1 and the terminal 6 of the battery element 25, and is positioned and laminated while sandwiching it between upper and lower exterior members. Is sealed. Since the positioning between the battery element and the member 26 is unnecessary, it is only necessary to position the battery element with care so that there is no deviation between the two holes. By enlarging one hole, particularly the hole of the exterior member, , Can be easily positioned. Also, as shown in the figure, 26 is provided in a portion where the active material layer of the battery element does not exist,
Do not increase the overall thickness. However, the structure of the member 26 is complicated because the structure avoids the thickness of the terminal, and the component cost slightly increases. Table 3 below shows the positioning tact of the first embodiment and the ninth embodiment and the subsequent tact of the lamination process in four stages. In addition, the case where the thickness of the container is increased is indicated by x, and the case where the thickness is not changed is indicated by ○.

[0026]

[Table 3]

10. FIGS. 10A and 10B are schematic views showing an embodiment (Embodiment 10) satisfying the constitutional requirements of claim 10, wherein FIG. 10A shows a case where the hole 28 of the exterior member is on the upper surface, and FIG. Is formed by a side surface or a plurality of exterior members. Reference numeral 27 denotes an elongated member, which has external terminals 29 and 3 for positive and negative electrodes.
0 is embedded in advance and is connected to the internal terminal inside the outer container.
Reference numeral 2 denotes an exterior member that closes the hole 31, and reference numeral 33 denotes a heat-sealed portion. FIG. 10 (a) shows that a compact and highly reliable strong terminal can be easily realized by also using a member for liquid injection, and at the same time, since the number of holes in the exterior member is the same, an increase in moisture or the like is caused. Sealing failure is unlikely to occur. FIG.
In (b), since the terminals are provided in a flat direction, the flat thinness can be maintained even in a state of connection with the outside, which is effective for thin devices.

11. FIG. 11 is a diagram showing an embodiment (Embodiment 11) that satisfies the constitutional requirements of claim 11.
(A) shows a state in which a battery with a laminate exterior is fixed to a package or a device for use, and (b) shows a state in which the battery with a laminate exterior is fixed to the package or a device and an electrical output is taken out from a thin plate terminal. Yes, 37 is a battery, 34 is a package, 35 is a fixing spring member, 36
Is a fixing abutting member, 38a and 38b are fixing and current collecting spring members, and 39 is used equipment. The laminate casing is inherently a film-like casing and therefore has low strength, and is different from other can-type batteries in a method of fixing and using in a device. That is, when the laminated portion is sandwiched and fixed, the laminated portion is easily broken, and when the thin terminal portion is sandwiched and fixed, the terminal is easily broken. But,
In the present embodiment, since the member is provided inside the laminate exterior, even if the laminate is fixed as it is or together with the terminal, the effect of preventing the lamination film and the terminal from being deformed and damaged by the internal member is prevented. There is. Conventionally, there is an example in which the outside of the laminate exterior is coated with a resin having high strength mainly for the purpose of improving the sealing ability. However, this is thicker and heavier. (A) and (b) when the battery is actually attached and detached with and without the member.
According to the above structure, it was found that, depending on the thickness of the exterior member and the terminal, the average life of the defective failure can be increased about twice or more, and the reliability can be improved. The average life of the failure failure was determined by simply examining the damage of the laminate film (those which caused visual deformation or sudden deterioration of capacity) and the damage of the terminal (visual deformation) in the number of times of attachment / detachment to equipment. It refers to the result.

12. FIG. 12 is a diagram showing an embodiment (Embodiment 12) that satisfies the constitutional requirements of claim 12. It is a view seen from the side surface, and even when the vicinity of the hole is wet with the electrolytic solution, the adhesion is very close by using the ionomer resin layer 40 as a heat-sealing agent of another exterior member 17 that closes the hole of the exterior member. It was found that sealing with high force and sealing force could be performed. Compared to the case of general polyethylene, a water increase of a fraction and a 50% increase in peel adhesion were obtained.

13. FIG. 13 is a view showing an embodiment (embodiment 13) that satisfies the constitutional requirements of claim 13 and is a view as viewed from the side, and epoxy bonding is performed on another exterior member itself that closes a hole of the exterior member. By using the agent layer 41, the hole of the exterior member could be easily closed. The shape of the hole can be freely adjusted, the productivity has increased, and the cost has decreased. The same applies to the case where at least one of a fusing agent, an adhesive, pitch or grease is used for the exterior member, and it is possible to easily close the holes by using a material having viscosity at least initially. Was. Of course, it is necessary to pay sufficient attention to the chemical resistance to these electrolytic solutions.

14. FIG. 14 is a diagram showing an embodiment (Embodiment 14) that satisfies the constitutional requirements of claim 14.
Reference numeral 16 in (a) denotes a member which is formed by bending a hole in the lateral direction, and the pressure and the temperature applied to the heat-sealing layer 42 are slightly smaller than those of the other portions, so that the inner portion is higher than the other portions. The sealing portion has a reduced strength against pressure, and the internal pressure rises so that the opening 43 can function as a safety valve as shown in FIG. A small cut is provided in the center of the polypropylene member 44.
The part 5 is heat-sealed, and if the inner part also increases, the strength is such that it can be broken with a smaller pressure than the laminated part of the other exterior members. Thus, it can function as a safety valve. As described above, by setting the strength and the adhesive force of the exterior member that closes the hole of the exterior member provided at a position overlapping with the member so as to be small, the safety valve can be easily provided without increasing the number of components.

Hereinafter, the manufacturing method will be described in detail. Positive electrode 1
No. 1 is a mixture of LiCoO ₂ , graphite and PVDF (polyvinylidene fluoride) in a weight ratio of 90: 7: 3 to obtain NMP (N-
Methyl-2-pyrrolidone) solution.
Coated on a 0 μm Al substrate, dried at 120 degrees
A positive electrode having an active material layer of 0 μm was produced. For the negative electrode, graphite and PVDF were dispersed in an NMP solution at a weight ratio of 90:10, and this was applied to a 10 μm Cu substrate,
After drying at 120 ° C., a negative electrode having an active material layer of about 70 μm was produced. Both the positive electrode and the negative electrode were roll-pressed before use. The electrolyte is a mixed solvent of EC (ethylene carbonate) and DMC (dimethyl carbonate).
An M-LiPF ₆ solution was used. A separator having a porosity of 40% or more and a thickness of 25 μm was used.

[0033] The positive active Substances, V ₂ 0 ₅ in addition to LiCoO _2, LiNiO _2, oxide, polyaniline involving intercalation of lithium such as LiMn ₂ O _4, a non-aqueous polymeric material such as polypyrrole, etc. Secondary battery cathode material,
The same applies to the use of water-based primary and secondary battery materials such as conventional dry batteries, alkaline batteries, and nickel hydrogen batteries. The graphite mixed with the positive electrode active material may be natural graphite, artificial graphite, or amorphous carbon. Further, in addition to PVDF, the binder may be a fluorine-containing NMP-soluble polymer, PVP (polyvinylpyrrolidone), or the like.

As the electrolyte, a non-aqueous electrolyte containing an acrylate monomer and a thermal polymerization initiator was used. In particular,
An electrolyte obtained by dissolving 1.5M LiPF ₆ in a mixed solvent of equal amounts of ethylene carbonate and dimethyl carbonate is added with about 13 wt% of a monofunctional monomer, 0.2 wt% of a trifunctional monomer and a thermal polymerization initiator. Using. Actually, as in the case of evacuation, the electrolytic solution is slowly but poured into the laminate outer container from a minute gap between the member 16 made of polytetrafluoroethylene and the laminate film 5. After the injection is completed, an exterior member 17 made of another laminated film is arranged above the hole 13, and the pressure is applied across the upper and lower portions of this portion and the temperature is applied only to the upper portion.
By applying 30 degrees for a short time, the holes 13 are closed by heat fusion. After that, the entire outer container is
The monomer is polymerized by leaving it to stand for a period of time, and the electrolytic solution is gelled to form a solid electrolyte to produce a polymer battery.

The electrolyte to be injected, which comprises the above-mentioned acrylic monomer and constitutes a solid electrolyte which can be gelled by thermal polymerization, includes carbonates such as cyclic carbonates, chain carbonates and carboxylic acid esters. , Acetonitrile, dimethylformamide, dimethylsulfoxide and the like, and non-aqueous secondary batteries may be water. The supporting salt is LiB
F ₄ , LiClO ₄ , LiAsF ₆ , LiSO ₃ CF ₃ , L
iC (SO ₂ CF ₃ ) ₃ or LiN (SO ₂ CF ₃ ) ₂ may be used. In addition, polymer particles such as polyacrylonitrile, polyethylene oxide, and polyvinyl copolymer may be dispersed in addition to the acrylic monomer containing the electrolyte. Further, a PVDF-HFP-based polymer may be used. The separator may not be used when a polymer is used.

As thermal polymerization initiators, azobisisobutyronitrile, benzoyl peroxide, lauroyl peroxide, ethyl methyl ketone peroxide, bis-
Peroxy dicarbonates such as (4-t-butylcyclohexyl) peroxy dicarbonate and diisopropyl peroxy dicarbonate can be exemplified. Acrylate-based monomers include (meth) acrylate, specifically acrylate or methacrylate, and monofunctional acrylates include alkyl (meth) acrylate ｛methyl (meth) acrylate, butyl (meth) acrylate, and trifluoroethyl (meth) acrylate. Acrylate, etc., alicyclic (meth) acrylate, hydroxyalkyl (meth) acrylate (hydroxyethyl acrylate, hydroxypropyl acrylate, etc.), hydroxypolyoxyalkylene (oxyalkylene group preferably has 1 to 4 carbon atoms) (meth) Acrylates {hydroxypolyoxyethylene (meth) acrylate, hydroxypolyoxypropylene (meth) acrylate, etc.}
And alkoxyalkyl (the alkoxy group preferably has 1 to 4 carbon atoms) (meth) acrylate {methoxyethyl acrylate, ethoxyethyl acrylate, phenoxyethyl acrylate, etc.}. Preferred examples of the trifunctional or higher polyfunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, pentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.
Specific examples of other (meth) acrylates include, for example, methyl ethylene glycol (meth) acrylate,
Ethyl ethylene glycol (meth) acrylate, propyl ethylene glycol (meth) acrylate, phenyl ethylene glycol, ethoxydiethylene glycol acrylate, methoxyethyl acrylate, methoxydiethylene glycol methacrylate, methoxytriethylene glycol acrylate, methoxytriethylene glycol methacrylate, methoxytetraethylene glycol methacrylate, etc. Alkyl propylene glycol (meth) acrylate such as alkyl ethylene glycol (meth) acrylate, ethyl propylene glycol acrylate, butyl propylene glycol acrylate, and methoxy propylene glycol acrylate. By using these acrylate monomers and the thermal polymerization initiator in an optimal formulation, it is possible to obtain a polymer electrolyte by performing thermal polymerization even at 60 ° C. for one hour to form a gel.

The laminate film may be a fusion material in which 25 μm thick aluminum is coated on the electrode side with polyethylene as a fusion material, and the outside is similarly coated with a polymer such as polyester. As the inner heat-sealing agent, besides polyethylene, polyolefin such as polypropylene, modified polyolefin containing carboxyl group, ionomer may be used, and a hot melt resin may be used as an adhesive layer, and an epoxy resin adhesive may be used. The layer may be provided only in the sealing portion. For the outer coating,
Polyimide, polyamide, polyphenylene oxide, etc. may be used, or the same polyolefin-based fusing material as the inside may be used. However, it is necessary to have excellent adhesion to another exterior member 17. Further, at least one of them is not a laminate film but a hard case, and the case may be sealed with a fusing material or an adhesive. In addition, the film structure of the sealing portion may not be apparently film-like as long as the electrode of the exterior member is sufficiently thin compared to the thickness of the outer member and fusion or adhesion is used.

[0038]

Advantages (1) Claims 1 to 6 A highly reliable vacuum injection can be performed in a short time. (2) Claims 7 to 9 The positioning and lamination steps during battery fabrication can be performed in a short time. it can. (3) Claim 10 A compact and highly reliable strong terminal can be easily realized. (4) Claim 11 In Claims 1 and 2, it is possible to provide a highly reliable battery that is hardly damaged at a part outside the exterior member overlapping the member. (5) Claims 12 and 13 The hole of the exterior member can be closed with high reliability or easily. (6) Claim 14 It can easily be used also as a safety valve.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating one embodiment of the present invention that satisfies the constitutional requirements of claim 1; (A) is a side view, (b) is a plan view.

FIG. 2 is a view for explaining an embodiment of a member satisfying the constitutional requirements of claim 2; (A) and (c) are side views, and (b) and (d) are plan views.

FIG. 3 is a view for explaining one embodiment of a member satisfying the constitutional requirements of claim 3; (A) is a side view, (b) is a plan view, and (c) is a left side view.

FIG. 4 is a view for explaining an embodiment of a member satisfying the constitutional requirements of claim 4; (A) is a plan view, (b) is a side view, and (c) is a bottom view as viewed from below.

FIG. 5 is a view for explaining an embodiment of a member satisfying the constitutional requirements of claim 5; (A) is a plan view, (b) is a side view, and (c) is a left side view.

FIG. 6 is a view for explaining an embodiment of a member satisfying the constitutional requirements of claim 6, and is a view as viewed from a side.

FIG. 7 is a view for explaining an embodiment of the present invention which satisfies the constitutional requirements of claim 7;

FIG. 8 is a diagram illustrating one embodiment of the present invention that satisfies the constitutional requirements of claim 8;

FIG. 9 is a view for explaining an embodiment of the present invention which satisfies the constitutional requirements of claim 9; (A) is a plan view and (b) is a side view.

FIG. 10 shows a first embodiment of the present invention which satisfies the constitutional requirements of claim 10;
It is a schematic diagram showing an embodiment. (A) is the hole 2 of the exterior member
8 is on the upper surface, and FIG.
Is on the side surface, and this member is in contact with one or more exterior members.

FIG. 11 is a view showing one embodiment of the present invention which satisfies the constitutional requirements of claim 11;
It is a figure explaining an embodiment. (A) shows a state in which a battery with a laminate exterior is used by being fixed to a package or equipment, and (b) shows a state in which the battery with a laminate exterior is fixed to the package or equipment and electrical output is taken out from a thin plate terminal. Show.

FIG. 12 shows a first embodiment of the present invention that satisfies the constitutional requirements of claim 12;
It is a figure explaining an embodiment.

FIG. 13 shows a first embodiment of the present invention which satisfies the constitutional requirements of claim 13;
It is a figure explaining an embodiment.

FIG. 14 is a view showing a first embodiment of the present invention satisfying the constitutional requirements of claim 14;
It is a figure explaining an embodiment. (A) shows the thermal fusion layer 42
And FIG. 3B shows a state in which the pressure and temperature applied to the heat-sealing are made smaller than those of the other parts, and FIG. 4B shows a state in which the hole is opened by the internal pressure, and FIG. It is a figure showing the state where a polypropylene member was closed by heat fusion to a hole.

FIG. 15 is a view illustrating a conventional flat battery.
(A) is a sectional view, and (b) is a plan view.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Positive electrode collector 2 Negative electrode collector 3 Separator layer 4 Positive-side exterior material (laminated film) 5 Negative-side exterior material (laminated film) 6 Positive electrode terminal 7 Negative electrode terminal 8 Gap part 9 Gap part 10A Heat fusion part 10B Heat Fused portion 10C Heat-fused portion 10D Non-heat-fused portion 11 Positive electrode active material layer 12 Negative electrode active material layer 13 Hole formed in 4 14 Coating layer (heat-fused layer) coated on positive electrode side laminate film 4 15 Negative electrode Coating layer (heat sealing layer) coated on side laminate film 5 16 Member (for example, square block made of polytetrafluoroethylene) 17 Exterior member different from 5 made of aluminum having heat sealing layer 18 18 Heat Fusion layer 19 Through hole provided in member 16 20 Notch provided in member 16 21 Through hole provided in member 16 22a Through hole provided in member 16 22b Through hole provided in member 16 23a Through hole provided in member 16 23b Through hole provided in member 16 23c Through hole provided in member 16 Vycor glass 25 Battery element 26 Member 27 Slender member 28 Hole in exterior member 29 External terminal of positive electrode 30 External of negative electrode Exterior member closing the hole 32 provided in the terminal 31 27 33 Thermal fusion layer 34 Package 35 Fixing spring member 36 Fixing butting member 37 Battery member 38a Fixing / collecting spring member 38b Fixing / collecting spring member Reference Signs List 39 Equipment used 40 Ionomer resin layer 41 Epoxy resin adhesive layer 42 Heat fusion layer 43 Opening 44 Polypropylene member with a cut in the center 45 Peripheral

Continued on front page (72) Inventor Toshige Fujii 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (14)

[Claims] An electrochemical element comprising at least two or more parts, at least one of which is in the form of a film, and an exterior member for accommodating an electrochemical element provided with a hole in the film-like exterior member, and an exterior member comprising A terminal for outputting a current or a voltage generated from the electrochemical element to the outside of the member, a member different from the electrochemical element or the terminal provided inside the exterior member near the hole of the film-shaped exterior member (hereinafter simply referred to as a member) And an exterior member that covers the hole, which is different from the exterior member provided with the hole. 2. The electrochemical device according to claim 1, wherein a hole or a cutout is provided in at least a part of the member at a position where the hole of the member and the hole of the exterior member overlap. 3. A hole or notch (A) in which a hole or notch of a member penetrates to a side different from the member-side exterior portion, and a hole or notch having a direction or shape different from that of the hole or notch. The electrochemical device according to claim 1, further comprising a notch (B), wherein the both holes or the notch are connected in the member. 4. A hole or notch (B) having a cross-sectional area of a hole or notch (A) penetrating to a side different from the member-side exterior part in a direction or shape different from that of the hole or notch.
4. The electrochemical device according to claim 3, wherein the cross-sectional area is equal to or smaller than the cross-sectional area of the electrochemical device. 5. The number of holes or notches (A) penetrating to a side different from the member-side exterior part is different from the number of holes or notches (B) in the direction or shape of the holes or notches. The electrochemical device according to claim 3, wherein the number is equal to or less than the number. 6. The electrochemical device according to claim 1, wherein at least a part of the hole or the cutout of the member has a microstructure. 7. The electrochemical device according to claim 1, wherein the exterior member and at least a part of the member are fixed. 8. The electrochemical device according to claim 1, wherein the member and at least a part of the electrochemical element or the terminal are fixed. 9. An electrochemical device, wherein the member is arranged so as to overlap with a connecting portion between the electrochemical element and the terminal or an exposed portion of the current collector of the electrochemical element. 10. A member having a part of a terminal.
10. The electrochemical device according to any one of 9 above. 11. A fixing device for an electrochemical element is provided on at least a part of an outer side of an exterior member overlapping with the member.
11. The electrochemical device according to any one of items 10 to 10. 12. The electrochemical element according to claim 1, wherein an ionomer resin is used as a part of an exterior member other than the exterior member having the hole that closes the hole of the exterior member. 13. A fusing agent, a part of an exterior member different from the exterior member having the hole that closes the hole of the exterior member,
The electrochemical device according to claim 1, wherein at least one of an adhesive, pitch, and grease is used. 14. The internal pressure fracture strength of a portion overlapping with another exterior member that is different from the exterior member having the hole closing the hole of the member and the exterior member has the smallest value among the exterior members. The electrochemical device according to claim 1, wherein