JP2000058026A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the mechanical strength of a bonding part of a terminal member by forming an electrode terminal member, while weaving lead wires into a vertical net having a longitudinal axis in the longitudinal director crossing the cross direction, in parallel with a connection part of a longitudinal one end and an electrode material. SOLUTION: A layered material of a positive electrode material 2 and a negative electrode material laminated through separator, made of the polymer including the gel-like electrolyte and formed by fitting the positive electrode material and the negative electrode material onto a strip positive electrode collector and a strip negative electrode collector, is sealed by a laminating material in a condition such that tips 8a, 9a of a positive electrode terminal member and a negative electrode terminal member 8, 9 connected to the layered structure are exposed. The positive electrode and the negative electrode terminal members 8, 9 are preferably formed into a vertical net by weaving narrow lead wires 10 of Ni or the like having a diameter at 50-300 μm at 30-90 degrees in crossing angle in the longitudinal direction, and quantity of the lead wire 10 to be used becomes larger than the case of a lateral net. Consequently, the cross-sectional area of the whole conductor becomes large, and since the deterioration of the welding strength to the laminate material 7 is prevented, strength in the tensile direction is improved. Moreover, the width is preferably set at 3 mm or more and less than half the width of the battery main body 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery having an electrode terminal member formed by weaving a conductive wire in a mesh shape and connecting a vertically long end to an electrode material, and more particularly to a tip of the electrode terminal member connected to the electrode material. It is suitably used for a thin battery or the like in which a battery main body is sealed with a laminate material in a state where a portion is exposed.

[0002]

2. Description of the Related Art A battery is defined as a device that converts chemical energy, physical energy, or biochemical energy into electrical energy, and is roughly classified into a chemical battery, a biological battery, a physical battery, and the like. For example, for a chemical battery, a primary battery in which the process of chemical change is not reversible or not configured to be rechargeable, a secondary battery in which the process of chemical change is reversible or configured to be rechargeable, and a reaction. Fuel cells and the like that promote a chemical reaction while supplying a substance involved in the reaction from the outside and extracting a reaction product to the outside are classified.

[0003] A battery is generally provided with an electrode terminal member for taking out a potential difference generated between the electrodes to the outside. As the electrode terminal member, generally, a lead-like conductor made of a conductor having good conductivity, a mesh-like conductor obtained by weaving a conductive wire having good conductivity in a mesh shape, or the like is used. For example, in a lithium ion battery, such a lead-like conductor or a mesh-like conductor is used, but an electrode terminal member having a positive electrode side formed of an aluminum material and a negative electrode side formed of a nickel material is used.

In portable equipment, a lithium ion secondary battery which can be repeatedly charged and has a large capacity is generally used as a power source.
As portable devices become more multifunctional, there is a demand for more secure portability as well as power supply capacity, and there is an increasing demand for thinner power supplies, in other words, thin batteries. A general lithium ion secondary battery is smaller and thinner than a dry battery or the like, but uses a liquid electrolyte as a conductive substance and is provided with a metal can to prevent leakage of the electrolyte. . Therefore, a general lithium ion secondary battery is
Since it is difficult to configure the metal can to be 4 mm or less in order to maintain the mechanical strength, there is a limit to the reduction in thickness.

Recently, lithium-ion batteries and polymer batteries using an all solid electrolyte or a gel electrolyte as an electrolyte have been receiving attention as ultra-thin batteries. For example, a polymer battery is formed by sandwiching a severator made of a polymer electrolyte material in the form of a film between a positive electrode material and a negative electrode material in a film form, and sealing the whole with a laminate material. The laminate material is made of a polymer multilayer film including at least one or more aluminum layers inside, and is heat-sealed around the laminate in a state where the laminate of each electrode material and the severator is sealed. In a polymer battery, an electrode terminal member is joined to each electrode material, and sealing with a laminate material is performed in a state where the tip portions of these electrode terminal members are exposed.

[0006] Solidified lithium ion secondary batteries are also
The basic configuration is almost the same as that of the polymer battery, and a positive electrode material and a negative electrode material are formed by applying a positive electrode active material and a negative electrode active material on a belt-shaped current collector, respectively. The positive electrode material and the negative electrode material are coated with a gel electrolyte in a molten state and overlapped via a severator. An electrode terminal member is connected to each of the positive electrode material and the negative electrode material.
The solidified lithium ion secondary battery is formed by further laminating the above-mentioned laminate, or winding it to be folded, and then sealing with a laminate material in a state in which the distal end of the electrode terminal member is exposed. You.

[0007]

In a battery, there is a need for a structure which maintains mechanical strength so that the electrode terminal member is not damaged by an externally applied force. Since the lead-shaped electrode terminal member has a relatively large diameter, a relatively large mechanical strength is maintained. On the other hand, since the mesh-shaped electrode terminal member is formed by weaving a small-diameter conductive wire, there is a problem that the electrode terminal member is easily damaged when an external force such as bending or tearing is applied.

On the other hand, in the above-mentioned solidified lithium ion secondary battery or polymer battery, since the electrode terminal member is pulled out from the bonding portion of the laminate material, the strength of the drawing portion is such that the mesh electrode terminal has a large bonding area. The member can obtain higher mechanical strength than the lead electrode terminal member. Further, since the mesh electrode terminal member is thinner than the lead electrode terminal member, it is possible to reduce the thickness of the entire battery.

For this reason, in a solidified lithium ion secondary battery or a polymer battery, a mesh electrode terminal member is generally used. However, while maintaining a small size and a thin shape, the battery body and the battery body are not subjected to external force such as bending or tearing. It is required that the joints have sufficient mechanical strength to further improve the reliability.

Therefore, the present invention has been proposed with the object of providing a highly reliable battery having a mesh electrode terminal member and improved mechanical strength at the joint.

[0011]

A battery according to the present invention that achieves this object is provided with an electrode terminal member formed by weaving a conductive wire in a mesh shape and connecting one end in a longitudinal direction to an electrode material. The terminal member is woven in a longitudinal mesh shape having a major axis in a length direction orthogonal to a width direction parallel to a connection portion with the electrode material.

According to the battery according to the present invention having the above-described structure, the electrode terminal member is woven in a vertical mesh having the longitudinal direction as a long axis, so that the electrode terminal member is stretched in the tensile direction. Strength is improved. Therefore, even when an external force such as bending or tearing is applied to the electrode terminal member, the battery is suppressed from being damaged and the reliability is improved.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. The battery shown in the drawings as an embodiment of the present invention has a structure in which a separator 4 made of a film-shaped polymer electrolyte material is sandwiched between a film-shaped cathode material 2 and a negative electrode material 3 to form a laminate. A polymer battery 1 in which a battery body 1a is formed to be ultra-thin by joining sealing materials 5 and 6 to the outer surfaces of the negative electrode material 2 and the negative electrode material 3, respectively, and then sealing the whole with a laminate material 7 is shown. In the polymer battery 1, as shown in FIG. 1, a positive electrode terminal member 8 and a negative electrode terminal member 9 are respectively joined to a positive electrode material 2 and a negative electrode material 3. As shown in FIG. 2, each of the positive electrode terminal member 8 and the negative electrode terminal member 9 has
And constitutes a connection part with the outside.

The polymer battery 1 has a basic structure similar to that of a lithium ion secondary battery, and a positive electrode material 2 is made of a lithium nickel oxide, a lithium cobalt oxide or a lithium cobalt oxide on a film-shaped current collector such as an aluminum foil. It is formed by forming a film of an electrode active material such as manganese oxide. In the polymer battery 1, the negative electrode material 2 is formed by doping lithium ions on a film-shaped current collector such as a copper foil.
It is formed by forming a film of an electrode active material made of a undoped carbon material or the like.

In the polymer battery 1, a general lithium ion battery uses an electrolytic solution as an electrolyte of a conductive substance interposed between a positive electrode material and a negative electrode material. This electrolytic solution is used as a solid polymer electrolyte. Sebalator 4 replaced by
Is interposed between the positive electrode material 2 and the negative electrode material 3 to form a laminate. That is, the polymer battery 1 is constituted by a gel electrolyte in which the separator 4 incorporates an electrolytic solution into a polymer. Polymer battery 1
Comprises a single-layer or multi-layer laminate of the positive electrode material 2, the negative electrode material 3, and the separator 4. Polymer battery 1
In the case of a multi-layer structure, after electrically connecting the respective positive electrode members 2 and between the negative electrode members 3, the positive electrode terminal member 8 is connected to the positive electrode member 2 and the negative electrode terminal member 9 is connected to the negative electrode member 3. Each is connected.

The laminate 7 is made of, for example, a moisture-proof polymer multilayer film including at least one or more metal foil layers such as an aluminum layer and a polymer layer. The laminate 7 encapsulates the laminate of the positive electrode material 2, the negative electrode material 3, and the separator 4, and heat-welds the laminate to seal the laminate. Laminate material 7
When sealing the laminate, the positive electrode terminal member 8 and the negative electrode terminal member 9 connected to the positive electrode material 2 and the negative electrode material 3, respectively, are welded in the thickness direction to be exposed to the outside.

The details of the positive electrode terminal member 8 and the negative electrode terminal member 9 will be described later, and a so-called mesh electrode terminal member in which a thin conductive wire 10 is woven in a mesh shape is used. Each of the positive electrode terminal member 8 and the negative electrode terminal member 9 is configured to have a rectangular shape having substantially the same outer dimensions. As shown in FIG. Electrical conduction is achieved by welding or the like to the joints 2a, 3a of the negative electrode material 3 and the negative electrode material 3 is connected with sufficient mechanical strength. The positive electrode terminal member 8 and the negative electrode terminal member 9 may be connected to the positive electrode member 2 and the negative electrode member 3 by performing, for example, an ultrasonic welding process.

The positive electrode terminal member 8 and the negative electrode terminal member 9 are connected to the positive electrode member 2 and the negative electrode member 3 while maintaining a sufficient interval so as not to contact each other, and are specifically set as follows. . That is, as shown in FIG. 2, the positive electrode terminal member 8 and the negative electrode terminal member 9 are exposed at the positions of the intervals D1 and D2 from both ends of the battery main body 1a. Interval D1, D
2 are substantially equal to each other, and there is no particular limitation on their dimensions. Further, the positive electrode terminal member 8 and the negative electrode terminal member 9
The mutual interval D3 is set in a range where they do not contact each other.

As described above, the positive electrode terminal member 8 and the negative electrode terminal member 9 are formed into a whole rectangular shape by weaving a small-diameter conductive wire 10 in a mesh shape, and have widths W1 and W2 of 3 mm or more. Thereby, it is configured such that the mechanical strength is maintained even in a mesh shape. The widths W1 and W2 of the positive electrode terminal member 8 and the negative electrode terminal member 9 are, of course, not more than half the width of the battery body 1a.

As the positive electrode terminal member 8, a member in which a conductive wire 10 made of, for example, aluminum or nickel is woven in a mesh shape is used. Further, as the negative electrode terminal member 9, one in which a conductive wire 10 made of, for example, copper or nickel is woven in a mesh shape is used. The conductor 10 has a circular cross section as shown in FIG.
Those having a diameter of 50 μm to 300 μm are used. When the diameter of the conductive wire 10 is 50 μm or less, the mechanical strength of the positive electrode terminal member 8 and the negative electrode terminal member 9 cannot be maintained. Further, when the diameter of the conductive wire 10 is 300 μm or more, the welding strength to the laminate 7 is deteriorated as described later. Of course, the conductor 10 may have an elliptical cross section.

Each of the positive electrode terminal member 8 and the negative electrode terminal member 9 is formed by weaving a conducting wire 10 in a mesh shape with its longitudinal direction as a long axis. That is, as shown in detail in FIG. 4, the positive electrode terminal member 8 and the negative electrode terminal member 9 have the long axis perpendicular to the connection parts 2a, 3a of the positive electrode material 2 and the negative electrode material 3, and the connection parts 2a, It is woven into a parallelogram whose minor axis is in the width direction parallel to 3a. The positive electrode terminal member 8 and the negative electrode terminal member 9 have a length M1 between the long axis intersections P1 and P2 of the parallelogram formed by the conducting wire 10, and a short axis intersection P3 and P
When the length between the four is M2, it is woven in a mesh shape satisfying the relationship of M1> M2.

Further, the positive electrode terminal member 8 and the negative electrode terminal member 9 have an intersection angle .theta.1 between the conductors 10a and 10b which intersect each other and forms the long axis side intersections P1 and P2.
It is configured to be 0 ° or less and woven in a mesh shape. The positive electrode terminal member 8 and the negative electrode terminal member 9 are connected at a short axis side intersection P3,
Intersection angle θ2 between the conductors 10a and 10c constituting P4
Is set to 90 ° or more and 150 ° or less and woven in a mesh shape.

The positive electrode terminal member 8 and the negative electrode terminal member 9 configured as described above have a so-called longitudinal shape in which the intersection angle θ1 of the long-axis intersections P1 and P2 is smaller than the intersection angle θ2 of the short-axis intersections P3 and P4. It is a mesh. Therefore, the positive electrode terminal member 8 and the negative electrode terminal member 9 have a larger number of conductors 10 than that of a so-called cross-mesh in the width direction, in other words, the total conductor cross-sectional area is larger and the material ratio is higher. The mechanical strength increases.

The positive terminal member 8 and the negative terminal member 9
Are connected to the positive electrode material 2 and the negative electrode material 3 as described above, and then are welded by the laminate material 7. The positive electrode terminal member 8 and the negative electrode terminal member 9 are welded to the laminate 7 by filling a parallelogram-shaped space defined by the respective conducting wires 10 with a polymer resin. In this case, the positive electrode terminal member 8 and the negative electrode terminal member 9
When the intersection angle θ of each conductor 10 is 30 ° or less, the amount of the polymer resin to be filled is reduced, and the welding strength is slightly deteriorated.

The positive electrode terminal member 8 and the negative electrode terminal member 9 maintain the welding strength with the laminate 7 by being sufficiently filled with the polymer resin at the intersections P3 and P4 on the short axis side. And the battery is pulled out from the battery main body 1a. The positive electrode terminal member 8 and the negative electrode terminal member 9 can thereby be prevented from being damaged even when an external force such as bending or tearing is applied.

Accordingly, even when an external force such as bending or tearing is applied to the positive electrode terminal member 8 or the negative electrode terminal member 9, the polymer battery 1 is prevented from being damaged and the reliability is improved.

Of course, the present invention relates to the polymer battery 1 described above.
However, the present invention is not limited to the solid-state lithium-ion battery having the same basic configuration, but is also applicable to various batteries. The battery is a chemical battery, a biological battery, or a physical battery, and is applied to a primary battery and a secondary battery. The battery to be applied may be any one in which the electrode terminal member is formed by weaving a conductive wire in a mesh shape. The electrode terminal member is not particularly limited in the material of the conductive wire, but generally, an aluminum material or a nickel material is used on the positive electrode side, and a copper material or a nickel material is used on the negative electrode side.

When the electrode terminal member is configured to be in contact with the electrolyte component, the electrode material is corroded by the electrolyte component, so that the nickel material cannot be used directly. Therefore, as the electrode terminal member, a member which has been subjected to a non-conductive treatment such as winding a Kavton tape or the like on the surface of a nickel material is used.

The significance of the battery using the above-mentioned electrode terminal member was confirmed by manufacturing a test apparatus 20 shown in FIG. 6 and performing a tensile strength test on the test apparatus 20. Example Test Equipment 20A, 20B
Like the positive electrode terminal member 8 and the negative electrode terminal member 9 described above, a so-called vertical mesh electrode terminal member having a long axis in a longitudinal direction with respect to the width direction is provided. On the other hand, the comparative example test devices 20C and 20D each include a so-called horizontal mesh electrode terminal member woven in the width direction as the major axis with respect to the longitudinal direction.

In the first test apparatus 20A, one of the electrode terminal members 21A is made of aluminum material for the conductor 10 and is woven in the longitudinal direction, and the other electrode terminal member 22A is made of the nickel material for the conductor 10. It is woven in the vertical direction. The second embodiment test apparatus 20B includes electrode terminal members 21B and 22B.
Are made of nickel material for the conductive wire 10 and are woven in the longitudinal direction. On the other hand, in the first comparative example 20C, one of the electrode terminal members 21C is made of aluminum material for the conductive wire 10 and woven sideways, and the other electrode terminal member 22C is made of a nickel material for the conductive wire 10. It is woven to the side. The second comparative example test device 20D includes the electrode terminal member 2
1D and 22D are each woven by using a nickel material for the conductive wire 10.

Each of the above-mentioned test devices 20 is sandwiched between two polyethylene films 23 and 24 as a laminate from both sides in a state where the electrode terminal member 21 and the electrode terminal member 22 are parallel to each other. This is subjected to a heat welding process. Each of the polyethylene films 23 and 24 has a thickness of 0.1 mm, and is subjected to a heat welding process with the welding portion 25 being 4 cm ² .

In the tensile strength test, the polyethylene films 23 and 24 were pulled at a constant speed with respect to each of the above-described test devices 20 using a tensile tester, and the loads at the maximum load points at which breakage occurred were measured. As a result of this measurement,
The load at the maximum load point was 7.39 kgf for the test apparatus 20A of the first example. The load at the maximum load point of the test apparatus 20B of the second example was 8.15 kgf. On the other hand, as for the first comparative example test device 20C, the load at the maximum load point was 6.
It was 06 kgf. With respect to the second comparative example test device 20D, the load at the maximum load point was 6.79 kgf.

As apparent from the above tensile strength test, the tensile strength of the test apparatus 20A of the first embodiment is approximately 22 times that of the tensile strength test apparatus 20C of the first comparative example.
% Or more. Similarly, the second comparative example test apparatus 20D is also used for the second comparative example test apparatus 20B.
The tensile strength is increased by 20% or more as compared with. Therefore, since the electrode terminal members 21 and 22 are woven in a vertical mesh pattern, the electrode terminal members 21 and 22 are welded in the welding portion 25 as compared with horizontal electrode mesh elements formed of the same material. It is confirmed that the strength is improved.

Next, regarding the significance of the battery using the above-described electrode terminal member, a test device 30 shown in FIG. 7 was manufactured, and a liquid leakage test was performed on the test device 30 to confirm the result. Was. The test apparatus 30 is formed by heat-welding a pair of mesh-shaped electrode terminal members 31 and 32 to an aluminum laminate pack 33 and filling the aluminum laminate pack 33 with 5 g of an electrolytic solution. The electrolyte is prepared by dissolving 1.2 mol / kg of LiPF ₆ as an electrolyte salt in propylene carbonate as a solvent.

The test apparatus 30 includes one electrode terminal member 3
1 is woven in a mesh using an aluminum material for the conductive wire, and the other electrode terminal member 32 is woven in a mesh using a nickel material for the conductive wire. The test apparatus 30 is formed by subjecting the electrode terminal members 31 and 32 to a heat-sealing process in a state where the electrode terminal members 31 and 32 are sandwiched by an aluminum laminate pack 33, and has the same configuration as the polymer battery 1 as a whole.

As in the case of the positive electrode terminal member 8 and the negative electrode terminal member 9 described above, the test apparatus 30A has a so-called longitudinal mesh electrode terminal member 31A whose longitudinal direction is a long axis with respect to the width direction. , 32A are used. On the other hand, the comparative example test device 30B has a so-called cross-meshed electrode terminal member 31 woven in the width direction with the major axis in the longitudinal direction.
B, 32B.

In the liquid leakage test, the test apparatus 30 constructed as described above was placed in a vacuum desiccator, and the weight change rate with respect to the evacuation time was measured. The weight change rate is a value obtained by calculating the percentage change in weight between the weight of the test apparatus 30 before measurement and the weight after measurement. FIG. 8 shows an example test device 30A and a comparative example test device 30 based on the above-described liquid leakage test.
FIG. 9 is a diagram in which the measurement results with B are plotted as the weight change rate (%) on the vertical axis and the measurement time (H) on the horizontal axis. Note that, in the same figure, a minus sign indicates a result that the weight after measurement is reduced with respect to the weight before measurement.

As can be seen from the figure, the test apparatus 30A of the embodiment has a smaller weight change rate than the test apparatus 30B of the comparative example, in other words, the leakage of the electrolyte is extremely small. Therefore, the device 30A for testing the example uses the mesh electrode terminal members 31A, 32A in the vertical direction, compared with the device 30B for the comparative example using the mesh electrode terminal members 31B, 32B in the horizontal direction. The sealing performance of the aluminum laminate pack 33 is maintained.

[0039]

As described above in detail, according to the battery according to the present invention, since the electrode terminal member woven in a vertical mesh having the major axis in the longitudinal direction is used, this battery is used. Even when an external force such as bending or tearing is applied to the terminal member, the damage is suppressed and reliability is improved. Further, according to the battery of the present invention, the mechanical strength of the electrode terminal member itself is large, and the polymer film is efficiently filled in the mesh when sealed with the laminate material, so that the bonding strength with the laminate material is improved. , A highly reliable polymer battery can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part for explaining a configuration of a thin battery such as a polymer battery shown as an embodiment of a battery according to the present invention.

FIG. 2 is a front view illustrating a schematic configuration of the thin battery.

FIG. 3 is a diagram illustrating a configuration in which an electrode terminal member provided in the thin battery is attached to an electrode material.

FIG. 4 is a diagram illustrating a detailed structure of the electrode terminal member.

FIG. 5 is a perspective view of a main part of a conductive wire used for the electrode terminal member.

FIG. 6 is an explanatory view of a test device used for a tensile test.

FIG. 7 is a front view of a test device used for a liquid leakage test of the thin battery.

FIG. 8 is a view showing the results of the liquid leakage test.

[Explanation of symbols]

Reference Signs List 1 polymer battery (thin battery), 2 positive electrode material, 3 negative electrode material, 4 separator, 5 sealing material, 6 sealing material, 7 laminate material, 8 positive electrode terminal member, 9 negative electrode terminal member, 1
0 conductor

Continued on the front page F term (reference) 5H022 AA09 BB01 CC02 CC09 CC12 CC16 CC21 5H024 AA00 AA02 BB00 CC04 CC16 DD11 HH00 HH13 5H029 AJ11 AK03 AL06 AM01 AM11 BJ04 BJ12 DJ05 EJ01 HJ00 HJ04 HJ05

Claims (4)

[Claims] 1. A battery having an electrode terminal member formed by weaving a conductive wire in a mesh shape and connecting one end in a length direction to an electrode material, wherein the mesh is formed in a width direction parallel to a connection portion with the electrode material. A battery comprising an electrode terminal member woven in a longitudinal direction with a longitudinal direction perpendicular to the longitudinal direction as a major axis. 2. The method according to claim 1, wherein the electrode material comprises a positive electrode material formed by applying a positive electrode active material on a band-shaped positive electrode current collector, and a negative electrode material formed by applying a negative electrode active material on a band-shaped negative electrode current collector. The positive electrode material and the negative electrode material are laminated via a severator, and the electrode terminal members are connected to each other. Using a non-aqueous electrolyte, a solid electrolyte, or a gel electrolyte as an electrolyte, the tip of the electrode terminal member is The laminated body of the positive electrode material, the negative electrode material, and the separator is sealed with a laminate material in an exposed state, and is constituted.
The battery according to 1. 3. The electrode terminal member has a width of 3 mm or more, and is の of the length of a battery body obtained by sealing the positive electrode material, the negative electrode material, and the severator with a laminate material.
The battery of claim 1, wherein 4. The electrode terminal member is woven in a mesh shape by a conductive wire having a diameter of 50 μm to 300 μm, and a crossing angle of the conductive wire in a length direction orthogonal to a connection portion with the electrode material is 30 ° or more. The battery of claim 1, wherein the battery is woven less than 90 °.