JP2003007346A - Secondary lithium battery and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary lithium battery and a manufacturing method of the same, wherein the constitution of the battery is made compact so that the volume energy density of the battery is improved. SOLUTION: In the lithium battery, positive electrode plates and negative electrode plates are wound and laminated on the peripheral wall of a shallow cylindrical wound core to constitute an inner electrode body 61, which contains a nonaqueous electrode solution therein. Two electrode terminals are arranged on both ends of the inner electrode body, the electrode terminals having inner terminals 69A, 69B, outer terminals 70A, 70B, and battery lids 71A, 71B. Each electrode terminal is electrically connected to the inner electrode body via a plurality of strip current collecting tabs 65, 66. At least one of the electrode terminals has a pressure releasing hole in a position corresponding to the axis of the wound core. While one ends of a plurality of the strip current collecting tabs 65, 66 are arranged in a low in the direction almost perpendicular to the axis of the wound core, the surface of at least one of the current collecting tabs 65, 66 is made contact, i.e., connected to, the side wall of at least the inner terminal 69A or 69B of either of the electrode terminals. The other ends of a plurality of the strip current collecting tabs 65, 66 are fixed to the ends of the positive electrode plates or negative electrode plates of the inner electrode body 61, respectively.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a lithium secondary battery (hereinafter, also simply referred to as “battery”) and a method for manufacturing the same, and more specifically, a lithium secondary battery that saves space and improves volume energy density. The present invention relates to a battery and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, lithium secondary batteries have been widely used as a power source for electronic devices such as portable communication devices and notebook personal computers. In addition, there is an increasing demand for resource saving and energy saving for the protection of the global environment, and as a battery for driving a motor of an electric vehicle or a hybrid electric vehicle (hereinafter, also simply referred to as “electric vehicle”), a lithium battery is used. Development of secondary batteries is underway.

This lithium secondary battery is constructed by winding or stacking a positive electrode plate and a negative electrode plate inside the positive electrode plate and the negative electrode plate so that the positive electrode plate and the negative electrode plate do not come into direct contact with each other via a separator made of a porous polymer film. Internal electrode body (hereinafter, also simply referred to as “electrode body”).

Conventionally, as shown in FIG. 8, for example, a wound type internal electrode body 61 is manufactured by winding a positive electrode plate 62 and a negative electrode plate 63 via a separator 64.
Each of the negative electrode plate 63 and the negative electrode plate 63 (hereinafter, also referred to as “electrode plate 62, 63”) has at least one positive electrode current collecting tab 65 and negative electrode current collecting tab 66 (hereinafter, “current collecting tab 6”).
5, 66 "). Then, as shown in FIG. 7, the ends of the current collecting tabs 65, 66 on the opposite side to the electrode plates 62, 63 are connected to the internal terminal portions 69A, 69B.
Etc. That is, the current collecting tabs 65, 66
Collects current from the electrode plates 62 and 63 and also serves as a lead wire. Reference numeral 10 is a communication hole, reference numeral 11 is a rivet, reference numeral 12 is a polypropylene ring, reference numeral 13 is a V-shaped groove, reference numeral 14 is a melt polypropylene, reference numeral 76 is an elastic body (packing), reference numeral 77. Indicates an insulating polymer film.

A positive electrode plate 62 is used as the electrode plates 62 and 63.
Is made of aluminum or the like, and the negative electrode plate 63 is made of a metal foil body of copper, nickel or the like as a current collector substrate, and is formed by applying an electrode active material to each of them, and the current collector tabs 65 and 66 are formed as described above. It is arranged on at least one side of the electric substrate. Therefore, if a strip-shaped current collecting tab that is thinner than the thickness of the electrode active material is used, when the electrode plate is wound, the shape of the current collecting tab is such that the current collecting tab partly bulges toward the outer periphery. Is less likely to occur, which is preferable.

However, the current collecting tabs 65 and 66 are
To connect the ends to the electrode plates 62 and 63 and connect the other end to the surfaces of the internal terminal portions 69A and 69B as shown in FIG. 7, a certain amount of space or more was required. In particular, when welding the current collecting tab and the internal terminal with an energy ray such as a laser, it is necessary to lengthen the current collecting tab in order to suppress the adverse effect on the electrode body due to the heat,
An even larger space was needed. Therefore, there is a problem that the volume energy density of the battery is small because the battery becomes large by the space. In addition, when a lithium secondary battery is used for driving a motor in an electric vehicle or the like, a large space is required because it is necessary to load a large number of batteries connected in series to extract a large current. was there.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above conventional problems, and an object of the present invention is to attach one end of a plurality of strip-shaped current collecting tabs to the center of a winding core. A structure in which at least one surface of the current collecting tab is connected in a state of being aligned in a direction substantially perpendicular to the axis while being in contact with a side wall of an internal terminal portion forming at least one of the electrode terminals. Is to provide a lithium secondary battery that saves space and improves the volume energy density, and a method for manufacturing the same.

[0008]

[Means for Solving the Problems] That is, according to the present invention, a positive electrode plate and a negative electrode plate are wound and laminated on an outer peripheral wall of a hollow cylindrical winding core, and a non-aqueous electrolysis is formed therein. A plurality of strips each including an internal electrode body impregnated with the liquid and two electrode terminals each having an internal terminal portion, an external terminal portion, and a battery lid portion, which are arranged at both ends of the internal electrode body. A lithium secondary battery electrically connected through a current collecting tab, wherein at least one of the electrode terminals has a pressure release hole at a position corresponding to the center axis of the winding core. One end of the strip-shaped current collecting tab is aligned in a direction substantially perpendicular to the center axis of the winding core, and at least one surface of the plurality of current collecting tabs has at least one electrode terminal. While connected to the side wall of the internal terminal part of,
Provided is a lithium secondary battery characterized in that the other ends of a plurality of current collecting tabs are fixed to respective end portions of a positive electrode plate and a negative electrode plate of an internal electrode body.

Further, according to the present invention, an inner electrode is formed by winding and stacking a positive electrode plate and a negative electrode plate on the outer peripheral wall of a hollow cylindrical winding core, and impregnating a non-aqueous electrolyte therein. Body, a cylindrical battery case having the internal electrode body housed therein and open at both ends, and an internal terminal portion, an external terminal portion, and a battery in which the internal electrode body is sealed at both open ends of the battery case. Two electrode terminals each having a lid portion, each of which is electrically connected to each of the internal electrode body and the electrode terminals via a plurality of strip-shaped current collecting tabs. A lithium secondary battery, one of which is provided with a pressure release hole at a position corresponding to the center axis of the winding core, wherein one end of a plurality of strip-shaped current collecting tabs is substantially perpendicular to the center axis of the winding core. In the correct orientation and at least one of the multiple If at least one of the electrode terminals is in contact with the side wall of the internal terminal portion, the connection is made, and the other end of the current collecting tab is fixed to each of the positive electrode plate and the negative electrode plate of the internal electrode body. A lithium secondary battery is provided.

In the present invention, the center axis of the winding core is preferably coaxial with the center axis of the battery case,
It is preferable that the external terminal portion has a hollow portion, and this hollow portion serves as a pressure release passage of the pressure release hole. Further, the thickness of one of the current collecting tabs is 5 μm or more and 100 μm or less, and
At least 10 current collecting tabs are preferably connected to one location of the internal terminal portion.

According to the present invention, an inner electrode is formed by winding and stacking a positive electrode plate and a negative electrode plate on an outer peripheral wall of a hollow cylindrical winding core and impregnating a non-aqueous electrolytic solution therein. Body and internal terminal portions arranged at both ends of the internal electrode body,
A lithium secondary battery in which an external terminal portion and each of two electrode terminals having a battery lid portion are electrically connected via a plurality of strip-shaped current collecting tabs. One end of the current collector tab is inserted into a groove formed in the side wall of the internal terminal portion forming at least one of the electrode terminals, and the other end of the current collecting tab is fixed to the end portions of the positive electrode plate and the negative electrode plate of the internal electrode body. Thus, there is provided a lithium secondary battery characterized in that the internal electrode body and the electrode terminal are electrically connected.

Further, according to the present invention, an inner electrode is formed by winding and stacking a positive electrode plate and a negative electrode plate on an outer peripheral wall of a hollow cylindrical winding core, and impregnated with a non-aqueous electrolytic solution inside thereof. Body, a cylindrical battery case having the internal electrode body housed therein and open at both ends, and an internal terminal portion, an external terminal portion, and a battery in which the internal electrode body is sealed at both open ends of the battery case. A lithium secondary battery comprising: two electrode terminals having a lid, and electrically connecting the internal electrode body and each of the electrode terminals via a plurality of strip-shaped current collecting tabs. Then, one end of the current collecting tab is inserted into the concave groove formed in the side wall of the internal terminal portion forming at least one of the electrode terminals, and the other end of the current collecting tab is connected to the positive electrode plate and the negative electrode plate of the internal electrode body. By fixing it to the end of the Provided is a lithium secondary battery characterized by being connected. At this time, the concave groove may be circumferentially provided on the side wall of the internal terminal portion, and as the plurality of current collecting tabs, they are put together in at least one place and inserted into the concave groove of the internal terminal portion to be connected. It is preferable.

In the present invention, it is preferable that one of the current collecting tabs has a thickness of 5 μm or more and 100 μm or less, and at least 10 current collecting tabs are connected to one location of the internal terminal portion. Also, at least one of the electrode terminals,
It is preferable to provide a pressure release hole at a position corresponding to the central axis of the winding core, the central axis of the winding core is preferably coaxial with the central axis of the battery case, the external terminal portion has a hollow portion, It is preferable that this hollow portion serves as a pressure release passage of the pressure release hole.

The constitutional conditions of the present invention are suitably adopted for a lithium secondary battery having a capacity of 2 Ah or more, and specifically, suitable for in-vehicle use, for engine starting or for electric vehicles and hybrid electric vehicles. Used.

Further, according to the present invention, each of the current collecting tabs provided at both ends of the internal electrode body formed by winding the positive electrode plate and the negative electrode plate around the outer periphery of the winding core via the separator, the internal terminal portion, and the external Two electrode terminals having a terminal portion and a battery lid portion are electrically connected to each other to form an electrical connection body, and the electrical connection body is housed in a cylindrical battery case with both ends open. A method for manufacturing a lithium secondary battery, in which a battery case and an outer edge portion of an electrode terminal are joined and sealed, wherein one end of a plurality of strip-shaped current collecting tabs provided at both ends of an internal electrode body is wound around a core. In the state of being aligned in a direction substantially perpendicular to the center axis of
Manufacture of a lithium secondary battery characterized by using an electrical connection body in which at least one surface of a current collecting tab is connected in a state of being in contact with a side wall of an internal terminal portion forming at least one of electrode terminals. A method is provided.

Further, according to the present invention, each of the current collecting tabs provided at both ends of the internal electrode body formed by winding the positive electrode plate and the negative electrode plate around the winding core through the separator, the internal terminal portion, and the external The electrical connection body is formed by joining the recessed groove formed in the side wall of each internal terminal portion, which constitutes the two electrode terminals having the terminal portion and the battery lid portion, and then formed the electrical connection body. After the connection body was inserted into a battery case with both ends open, both end portions of the battery case were joined to respective outer edge portions of the two electrode terminals, and then provided on at least one electrode terminal. Provided is a method for manufacturing a lithium secondary battery, which comprises sealing the electrolyte solution inlet after injecting the non-aqueous electrolyte solution from the electrolyte solution inlet.

In the present invention, a crimping and / or welding method may be used as a method for joining the concave groove of the internal terminal portion and the current collecting tab, and the current collecting tab is crimped and / or welded during the joining operation. It is preferable to dispose the electrode terminal at a position where it is easy to do.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the lithium secondary battery of the present invention is formed by winding and stacking the positive electrode plate and the negative electrode plate on the outer peripheral wall of the hollow cylindrical winding core 67 as described above. And an internal electrode body 61 having a non-aqueous electrolyte impregnated therein,
Internal terminal portions 6 arranged at both ends of the internal electrode body 61
9A, 69B, external terminal portions 70A, 70B, and two electrode terminals each having a battery lid portion 71A, 71B are electrically connected via a plurality of strip-shaped current collecting tabs 65, 66. A lithium secondary battery 68 in which at least one of the electrode terminals is provided with a pressure release hole 75 at a position corresponding to the central axis of the winding core 67, as shown in FIG. One end of the current collecting tabs 65, 66 of the
Of the plurality of current collecting tabs 65, 66 in a state of being aligned in a direction substantially perpendicular to the central axis of the inner terminal portion 69A of at least one of the electrode terminals,
While connecting to the side wall of 69B,
The other ends of the plurality of current collecting tabs 65 and 66 are connected to the internal electrode body 61.
The positive electrode plate and the negative electrode plate are fixed to the respective ends.

As described above, the current collecting tabs 65 and 66 are housed inside the electrode terminals in a manner that the current collecting tabs 65 and 66 are housed.
A space is saved and the volumetric energy density is improved by adopting a configuration in which one end of the terminal is connected to the electrode terminals from the direction substantially perpendicular to the central axis of the winding core 67 on the side walls of the internal terminal portions 69A and 69B. You can Further, when a large number of lithium secondary batteries are used for driving a motor in an electric vehicle or the like, the individual batteries are made compact, so that the space required for loading the batteries can be reduced.

The “internal terminal portion” here does not structurally indicate a specific portion of the electrode terminal, but means a portion to which the current collecting tab of the electrode terminal is directly connected. is there.

The electrode terminals used in the present invention include:
There is no particular limitation and, for example, a general molding method can be used.

The material of the electrode terminal is not particularly limited as long as it is compatible with the electrochemical reaction of the positive electrode and the negative electrode, and a general-purpose metal material can be used. For example, the positive electrode may be aluminum or its alloy, and the negative electrode may be copper, nickel, or an alloy thereof.

The collector tab used in the present invention is not particularly limited as long as it is a strip-shaped metal foil body corresponding to the electrochemical reaction of the positive electrode and the negative electrode, and a general-purpose metal material can be used. For example, the positive electrode may be aluminum or its alloy, and the negative electrode may be copper, nickel, or an alloy thereof.

As a method of connecting the other end of the current collecting tab and the internal electrode body, a separator is sandwiched between the positive electrode plate and the negative electrode plate on the outer peripheral wall of the winding core, and while winding them,
No electrode active material is applied by ultrasonic welding,
A method of attaching the positive electrode plate and the negative electrode plate where the metal foil is exposed to the end portions at regular intervals can be mentioned.

The internal terminal portion of the electrode terminal is connected to the current collecting tab, and the external terminal portion is connected to a bus bar or the like for deriving a current from the battery, so that the internal terminal is suppressed in order to suppress the connection resistance. It is preferable that the portion and the current collecting tab are made of the same metal as that of the external terminal portion and the bus bar.

Further, as shown in FIG. 2, in the lithium secondary battery of the present invention, at least one of the electrode terminals has a winding core 6
It is preferable to provide the pressure release hole 75 at a position corresponding to the central axis of 7, but at this time, the central axis of the winding core 67 is preferably coaxial with the central axis of the battery case 73, and the external terminal portion 70A. , 70B has a hollow portion, and this hollow portion serves as a pressure release passage of the pressure release hole 75. According to the present invention, the conventional pressure-releasing function is achieved by connecting the side wall of the internal terminals 69A, 69B to the portion that does not block the pressure-releasing passage from a direction substantially perpendicular to the central axis of the winding core 67. It is intended to save space while holding.

In the present invention, the thickness and the number of the current collecting tabs used in the present invention are not particularly limited, but it is preferable that the thickness of one current collecting tab is 5 μm or more and 100 μm or less, Moreover, it is preferable that at least 10 current collecting tabs are connected to one location of the internal terminal portion in order to suppress the connection resistance and simplify the connection of the current collecting tabs.

Although the suitable thickness range varies depending on the material of the current collecting tab, in the lithium secondary battery of the present invention, for example, when the current collecting tab is aluminum or aluminum alloy, it is 15 μm to 25 μm. It is preferably 7 μm to 15 μm for copper or a copper alloy.

Further, as shown in FIG. 2, the lithium secondary battery of the present invention, as described above, has a hollow cylindrical winding core 67.
An inner electrode body 6 in which a positive electrode plate and a negative electrode plate are wound and laminated on the outer peripheral wall of and the nonaqueous electrolytic solution is impregnated into the inner electrode body 6.
1, a cylindrical battery case 73 in which the internal electrode body 61 is housed, the both ends of which are open, and the battery case 7
The internal electrode body 61 is sealed at both open ends of 3 and has two electrode terminals having internal terminal portions 69A and 69B, external terminal portions 70A and 70B, and battery lid portions 71A and 71B. The body 61 and each of the electrode terminals are electrically connected via a plurality of strip-shaped current collecting tabs 65 and 66, and at least one of the electrode terminals is located at a position corresponding to the central axis of the winding core 67. In a lithium secondary battery 68 including pressure release holes 75, as shown in FIG. 1, one end of a plurality of strip-shaped current collecting tabs 65, 66 is substantially aligned with a center axis of a winding core 67. Current collecting tab 6 in a state of being aligned in a vertical direction
The surfaces of at least one of the plurality of sheets 5 and 66 are connected in a state of being in contact with the side walls of the internal terminal portions 69A and 69B of at least one of the electrode terminals.
Alternatively, the other ends of the plurality of sheets 5 and 66 may be fixed to the respective ends of the positive electrode plate and the negative electrode plate of the internal electrode body 61. Since the specific configuration and the technical effect thereof according to the present invention have been described above, the overlapping portions will be omitted.

Further, as shown in FIG. 2, the lithium secondary battery of the present invention, as described above, has a hollow cylindrical winding core 67.
An inner electrode body 6 in which a positive electrode plate and a negative electrode plate are wound and laminated on the outer peripheral wall of and the nonaqueous electrolytic solution is impregnated into the inner electrode body 6.
1 and two electrode terminals having internal terminal portions 69A and 69B, external terminal portions 70A and 70B, and battery lid portions 71A and 71B, which are arranged at both ends of the internal electrode body 61, respectively. A lithium secondary battery 68 electrically connected through a plurality of strip-shaped current collecting tabs 65 and 66, wherein one end of the current collecting tabs 65 and 66 is
Internal terminal portion 69 constituting at least one of electrode terminals
The inner electrode body 61 is inserted into the groove 1 formed in the side walls of A and 69B, and the other ends of the current collecting tabs 65 and 66 are fixed to the ends of the positive electrode plate and the negative electrode plate of the inner electrode body 61. And an electrode terminal are electrically connected to each other. At this time, the internal groove 69 is used as the groove 1.
It is preferable to be provided around the side walls of A and 69B. Since the specific configuration and the technical effect thereof according to the present invention have been described above, the overlapping portions will be omitted.

In this way, the current collecting tabs 65, 66 are housed inside the electrode terminals in such a manner that the current collecting tabs 65, 66 are housed.
By adopting the configuration in which one end of the above is inserted into the groove 1 formed in the side walls of the internal terminal portions 69A and 69B and connected to the electrode terminal, space saving can be achieved and the volume energy density can be improved. Further, when a large number of lithium secondary batteries are used for driving a motor in an electric vehicle or the like, the individual batteries are made compact, so that the space required for loading the batteries can be reduced.

At this time, the plurality of current collecting tabs 65, 66
However, the internal terminal portions 69 are gathered in at least one place.
It is preferable to be inserted and connected to the recessed grooves 1 of A and 69B from the viewpoint of easy connection. In particular, as shown in FIG.
If a plurality of current collecting tabs 65, 66 are put together in one place and inserted into the concave grooves 1 of the internal terminal portions 69A, 69B and connected, the pressure release passage described later will not be blocked at all.
More preferable.

As a method of connecting one end of the current collecting tab and the concave groove 1 of the internal terminal portion, a method of crimping and / or welding can be mentioned. At this time, examples of welding include arc welding using energy rays, laser welding, electron beam welding, ultrasonic welding, resistance welding, and spot welding.

Further, as shown in FIG. 2, the lithium secondary battery of the present invention, as described above, has a hollow cylindrical winding core 67.
An inner electrode body 6 in which a positive electrode plate and a negative electrode plate are wound and laminated on the outer peripheral wall of and the nonaqueous electrolytic solution is impregnated into the inner electrode body 6.
1, a cylindrical battery case 73 in which the internal electrode body 61 is housed, the both ends of which are open, and the battery case 7
The inner electrode body 61 is sealed at both open ends of the inner electrode body 3 and has two electrode terminals having inner terminal portions 69A and 69B, outer terminal portions 70A and 70B, and battery lid portions 71A and 71B. A lithium secondary battery 68 in which a body 61 and each of the electrode terminals are electrically connected via a plurality of strip-shaped current collecting tabs 65 and 66, and the lithium secondary battery 68 has a structure as shown in FIG. One end of each of the tabs 65 and 66 is inserted into the recessed groove 1 formed in the side wall of each of the internal terminal portions 69A and 69B forming at least one of the electrode terminals, and the current collecting tabs 65 and 66 are formed.
The inner electrode body 61 and the electrode terminal may be electrically connected by fixing the other end of the inner electrode body 61 to the ends of the positive electrode plate and the negative electrode plate of the inner electrode body 61. Since the specific configuration and the technical effect thereof according to the present invention have been described above, the overlapping portions will be omitted.

The constitutional conditions of the lithium secondary battery of the present invention are preferably used for a device having a relatively large capacity in which it is preferable to use a plurality of current collecting tabs. Specifically, the wound type electrode body is preferably used for those having a capacity of 2 Ah or more. The application of the lithium secondary battery is not particularly limited, however, as a large-capacity vehicle-mounted device that is frequently discharged with a large current and is required to have a high energy density and a low internal resistance, for starting an engine, or for an electric vehicle. It can be used particularly preferably for driving a motor of a hybrid electric vehicle.

Further, as shown in FIG. 2, in the method for manufacturing a lithium secondary battery of the present invention, as described above, the outer peripheral wall of the hollow cylindrical winding core 67 with the positive electrode plate and the negative electrode plate via the separator. Current collecting tabs 65 and 66 provided at both ends of an internal electrode body 61 wound around the inner electrode body 61 and internal terminal portions 69A and 69, respectively.
B, the external terminal portions 70A and 70B, and the battery lid portion 71A,
After electrically connecting two electrode terminals having 71B to each other to form an electrical connection body, and housing the electrical connection body in a cylindrical battery case 73 having open ends, a battery case 73 is a method for manufacturing a lithium secondary battery 68 in which 73 and an outer edge portion of an electrode terminal are joined and sealed, and FIG.
As shown in (b), one end of a plurality of strip-shaped current collecting tabs 65, 66 provided at both ends of the internal electrode body 61 is aligned in a direction substantially perpendicular to the central axis of the winding core 67. Then, it is preferable to use an electrical connector in which at least one surface of the current collecting tabs 65 and 66 is connected in contact with the side walls of the internal terminal portions 69A and 69B forming at least one of the electrode terminals. In the present specification, the electrical connection body specifically means a plurality of internal electrode bodies and electrode terminals arranged at both ends of the internal electrode body as shown in FIG. It is electrically connected via a strip-shaped collector tab. Needless to say, the electrical connection body shown in FIG. 4A is also an example.

Further, as described above, the method for manufacturing a lithium secondary battery of the present invention, as shown in FIGS. 3 (a) and 3 (b), hollows the positive electrode plate and the negative electrode plate via the separator. Internal electrode body 61 formed by winding the outer peripheral wall of a cylindrical winding core 67
Each of the current collecting tabs 65 and 66 provided at both ends of the terminal, the internal terminal portions 69A and 69B, the external terminal portions 70A and 70B, and the battery lid portions 71A and 71B. The recesses 1 formed in the side walls of the internal terminal portions 69A and 69B are joined to form an electrical connection body, and then, as shown in FIGS. 4 (a), 4 (b) and 4 (c). After inserting the electrical connector into a battery case 73 whose both ends are open, the respective ends of the battery case 73 and the outer edges of the two electrode terminals are joined together. As shown in (a), FIG. 5 (b), and FIG. 5 (c), after injecting the nonaqueous electrolytic solution from the electrolytic solution injection port 81 provided in at least one electrode terminal, the electrolytic solution injection port 8
1 should be sealed.

Further, in the method for manufacturing a lithium secondary battery of the present invention, FIG. 6 (a), FIG. 6 (b), and FIG. 6 (c).
As shown in FIG. 7, a crimping and / or welding method may be used as a method for joining the concave groove 1 of the internal terminal portions 69A, 69B and the current collecting tabs 65, 66. It is preferable to place the electrode terminals at positions where it is easy to crimp and / or weld the electrodes 66. At this time,
The groove 1 and the current collecting tabs 65 and 66 can be joined only by pressure bonding, but welding the groove 1 and the current collecting tabs 65 and 66 is more preferable because the stability of the connection is improved. By these manufacturing methods, the lithium secondary battery described above can be manufactured easily and with high productivity.

The structure of the lithium secondary battery using the wound type internal electrode body will be described in more detail. Figure 8
The positive electrode plate 62 shown in is formed by applying a positive electrode active material to both surfaces of the current collector substrate. As the current collector substrate, a metal foil such as an aluminum foil or a titanium foil having good corrosion resistance against a positive electrode electrochemical reaction is used, but a punching metal or a mesh (mesh) may be used instead of the foil. As the positive electrode active material, lithium manganate (LiMn ₂ O ₄ ) or lithium cobalt oxide (LiCo) is used.
O ₂ ), lithium transition metal composite oxides such as lithium nickel oxide (LiNiO ₂ ) are preferably used, and preferably,
Carbon fine powder such as acetylene black is added to these as a conductive additive.

To coat the positive electrode active material, a slurry or paste prepared by adding a solvent, a binder or the like to the positive electrode active material powder is applied to a current collecting substrate by a roll coater method or the like.
It is performed by drying, and thereafter, a pressing process or the like is performed if necessary.

The negative electrode plate 63 can be formed in the same manner as the positive electrode plate 62. As the current collector substrate of the negative electrode plate 63, a metal foil such as a copper foil or a nickel foil having a good corrosion resistance against a negative electrode electrochemical reaction is preferably used. As the negative electrode active material, an amorphous carbonaceous material such as soft carbon or hard carbon, or highly graphitized carbonaceous powder such as artificial graphite or natural graphite is used.

The separator 64 preferably has a three-layer structure in which a Li ⁺ permeable polyethylene film (PE film) having micropores is sandwiched between porous Li ⁺ permeable polypropylene films (PP film). Used for. This is because the PE film is softened at about 130 ° C. and the micropores are crushed when the temperature of the electrode body rises, and also serves as a safety mechanism for suppressing the movement of Li ⁺ , that is, the battery reaction. By sandwiching this PE film with a PP film having a higher softening temperature, even when the PE film is softened, the PP film retains its shape so that the positive electrode plate 62 and the negative electrode plate 63 come into contact with each other.
It is possible to prevent short circuits, reliably suppress battery reactions, and ensure safety.

As the solvent of the non-aqueous electrolyte, ethylene carbonate (EC), diethyl carbonate (DE
C), dimethyl carbonate (DMC), propylene carbonate (PC) -based ones,
A single solvent or a mixed solvent of γ-butyrolactin, tetrahydrofuran, acetonitrile and the like is preferably used.

As the electrolyte of the non-aqueous electrolyte, a lithium complex fluorine compound such as lithium hexafluorophosphate (LiPF ₆ ) or lithium borofluoride (LiBF ₄ ) or a lithium halide such as lithium perchlorate (LiClO ₄ ). One kind or two or more kinds are dissolved in the solvent and used. In particular, it is preferable to use LiPF ₆ which does not easily undergo oxidative decomposition and has high conductivity of the non-aqueous electrolyte.

[0046]

As described above, according to the present invention, one end of a plurality of strip-shaped current collecting tabs is aligned in a direction substantially perpendicular to the central axis of the winding core, and the current collecting tab is arranged. By adopting a configuration in which at least one surface of the plurality of sheets is connected in contact with the side wall of the internal terminal portion of at least one of the electrode terminals, space saving is achieved,
It is possible to provide a lithium secondary battery having an improved volume energy density and a method for manufacturing the same.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an embodiment of a connection between an internal electrode body and an electrode terminal via a current collecting tab in a lithium secondary battery of the present invention.

FIG. 2 is a cross-sectional view showing an embodiment of the lithium secondary battery of the present invention.

FIG. 3 is a continuous cross-sectional view showing manufacturing steps (a) and (b) of the lithium secondary battery of the present invention.

FIG. 4 is a continuous cross-sectional view showing manufacturing steps (a), (b) and (c) of the lithium secondary battery of the present invention, which is subsequent to FIG. 3;

5 is a continuous cross-sectional view showing manufacturing steps (a), (b) and (c) of the lithium secondary battery of the present invention, which is subsequent to FIG.

FIG. 6 is a continuous cross-sectional view showing a method (a), (b), (c) for joining the internal terminal portion and the current collecting tab in the lithium secondary battery of the present invention.

FIG. 7 is a cross-sectional view showing an embodiment of a conventional lithium secondary battery.

FIG. 8 is a perspective view showing an example of a wound type internal electrode body.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Recessed groove, 10 ... Communication hole, 11 ... Rivet, 12 ... Polypropylene ring, 13 ... V-shaped groove, 14 ... Melting polypropylene, 61 ... Wound type internal electrode body, 62 ... Positive electrode plate, 6
3 ... Negative electrode plate, 64 ... Separator, 65 ... Positive electrode current collecting tab, 66 ... Negative electrode current collecting tab, 67 ... Core, 68 ... Battery,
69A ... Positive electrode internal terminal portion, 69B ... Negative electrode internal terminal portion, 7
0A ... Positive electrode external terminal portion, 70B ... Negative electrode external terminal portion, 71
A ... Positive battery cover, 71B ... Negative battery cover, 72 ... Vibration preventing member, 73 ... Battery case, 74 ... Constricted portion, 7
5 ... Pressure release hole, 76 ... Elastic body (packing), 77 ... Insulating polymer film, 78 ... Pressure release valve, 79 ... Metal foil, 80
... Nozzle, 81 ... Electrolyte injection port, 82 ... Electrolyte injection port sealing member, 83 ... Energy ray.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5H011 AA03 EE04 JJ04 JJ12 JJ27                       KK00 KK01                 5H022 AA09 BB03 BB11 CC03 CC16                       CC20 CC22                 5H029 AJ03 AK03 AL06 AL07 AL08                       AM02 AM03 AM05 AM07 BJ02                       BJ14 CJ05 DJ02 DJ05 EJ04                       HJ04 HJ19

Claims (21)

[Claims] 1. An internal electrode body, which is constructed by winding and stacking a positive electrode plate and a negative electrode plate on an outer peripheral wall of a hollow cylindrical winding core, and impregnated with a non-aqueous electrolytic solution in the inside, and the internal electrode. Two electrode terminals each having an internal terminal portion, an external terminal portion, and a battery lid portion, which are arranged at both ends of the body, are electrically connected to each other through a plurality of strip-shaped current collecting tabs. A lithium secondary battery in which at least one of the electrode terminals is provided with a pressure release hole at a position corresponding to the central axis of the winding core, wherein one end of the plurality of strip-shaped current collecting tabs is provided. , In a state of being aligned in a direction substantially perpendicular to the central axis of the winding core, and at least one surface of the plurality of current collecting tabs is at least one of the internal terminal portions of the electrode terminals. While being in contact with the side wall, while being connected, the other end of the plurality of current collecting tabs, A lithium secondary battery, characterized in that it is fixed to each of the ends of the positive electrode plate and the negative electrode plate of the internal electrode body. 2. An internal electrode body, which is constructed by winding and stacking a positive electrode plate and a negative electrode plate on an outer peripheral wall of a hollow cylindrical winding core, and impregnated with a non-aqueous electrolytic solution in the inside, and the internal electrode. It has a cylindrical battery case with both ends open and a body housed therein, and an internal terminal portion, an external terminal portion, and a battery lid portion in which the internal electrode body is sealed at both open ends of the battery case. Two electrode terminals are provided, and each of the internal electrode body and the electrode terminal is electrically connected via a plurality of strip-shaped current collecting tabs, and at least one of the electrode terminals is provided. A lithium secondary battery comprising a pressure release hole at a position corresponding to the center axis of the winding core, wherein one end of the plurality of strip-shaped current collecting tabs is substantially aligned with the center axis of the winding core. At least one of the plurality of current collecting tabs aligned in a vertical direction. Surface is in contact with the side wall of the internal terminal portion of at least one of the electrode terminals, and the other end of the current collecting tab is connected to the positive electrode plate and the negative electrode plate of the internal electrode body. A lithium secondary battery, characterized in that it is fixed to each of the ends. 3. The lithium secondary battery according to claim 1, wherein the center axis of the winding core is coaxial with the center axis of the battery case. 4. The external terminal portion has a hollow portion, and the hollow portion serves as a pressure release passage of the pressure release hole.
4. The lithium secondary battery according to any one of 3 above. 5. The collector tab according to claim 1, wherein one of the collector tabs has a thickness of 5 μm or more and 100 μm or less, and at least 10 collector tabs are connected to one location of the internal terminal portion. The lithium secondary battery according to any one of items. 6. An internal electrode body, which is constructed by winding and stacking a positive electrode plate and a negative electrode plate on an outer peripheral wall of a hollow cylindrical winding core, and impregnated with a non-aqueous electrolyte in the inside, and the internal electrode. Two electrode terminals each having an internal terminal portion, an external terminal portion, and a battery lid portion arranged at both ends of the body are electrically connected to each other through a plurality of strip-shaped current collecting tabs. In the lithium secondary battery, the one end of the current collecting tab is inserted into a groove formed in a side wall of the internal terminal portion forming at least one of the electrode terminals, and A lithium secondary battery, characterized in that the ends are fixed to the ends of the positive electrode plate and the negative electrode plate of the internal electrode body to electrically connect the internal electrode body and the electrode terminals. . 7. An internal electrode body, which is constructed by winding and stacking a positive electrode plate and a negative electrode plate on an outer peripheral wall of a hollow cylindrical winding core, and impregnated with a nonaqueous electrolytic solution in the inside, and the internal electrode. It has a cylindrical battery case with both ends open and a body housed therein, and an internal terminal portion, an external terminal portion, and a battery lid portion in which the internal electrode body is sealed at both open ends of the battery case. A lithium secondary battery comprising two electrode terminals, wherein the internal electrode body and each of the electrode terminals are electrically connected via a plurality of strip-shaped current collecting tabs, One end of the current collecting tab is inserted into a groove formed in a side wall of the internal terminal portion that constitutes at least one of the electrode terminals, and the other end of the current collecting tab is connected to the positive electrode plate of the internal electrode body. And the internal electrode by fixing to the end of the negative electrode plate. Lithium secondary battery, characterized by comprising electrically connecting the electrode terminals and. 8. The lithium secondary battery according to claim 6, wherein the groove is provided around a sidewall of the internal terminal portion. 9. The plurality of current collecting tabs are at least one.
The lithium secondary battery according to any one of claims 6 to 8, wherein the lithium secondary battery is grouped into a place and inserted into and connected to the recessed groove of the internal terminal portion. 10. The method according to claim 6, wherein one of the current collecting tabs has a thickness of 5 μm or more and 100 μm or less, and at least 10 current collecting tabs are connected to one location of the internal terminal portion. The lithium secondary battery according to any one of items. 11. The lithium secondary battery according to claim 6, wherein at least one of the electrode terminals has a pressure release hole at a position corresponding to the central axis of the winding core. 12. The lithium secondary battery according to claim 6, wherein a center axis of the winding core is coaxial with a center axis of the battery case. 13. The external terminal portion has a hollow portion, and the hollow portion serves as a pressure release passage of the pressure release hole.
The lithium secondary battery according to any one of 1 to 12. 14. The method according to claim 1, wherein the capacity is 2 Ah or more.
4. The lithium secondary battery according to any one of 3 above. 15. The lithium secondary battery according to claim 1, which is mounted on a vehicle. 16. The lithium secondary battery according to claim 15, which is for an electric vehicle or a hybrid electric vehicle. 17. The lithium secondary battery according to claim 15, which is for starting an engine. 18. A collector tab provided at each end of an internal electrode body formed by winding a positive electrode plate and a negative electrode plate around an outer peripheral wall of a hollow cylindrical winding core via a separator, an internal terminal portion, and an external portion. An electrical connection body is formed by electrically connecting two electrode terminals having a terminal portion and a battery lid portion, and the electrical connection body is housed in a cylindrical battery case with both ends open. After that, a method for manufacturing a lithium secondary battery, in which the battery case and the outer edge of the electrode terminal are joined and sealed, wherein the plurality of strip-shaped current collecting tabs provided at both ends of the internal electrode body are provided. A side wall of the internal terminal portion that constitutes at least one of the electrode terminals, with at least one surface of the current collecting tab being aligned in a direction substantially perpendicular to the central axis of the winding core. Characterized by using an electrical connector that is connected in contact with Method of manufacturing a lithium secondary battery. 19. A collector tab provided at each end of an internal electrode body formed by winding a positive electrode plate and a negative electrode plate around an outer peripheral wall of a hollow cylindrical winding core via a separator, an internal terminal portion, and an external portion. An electric connection is formed by joining the groove formed in the side wall of each of the internal terminal portions forming the two electrode terminals having the terminal portion and the battery lid portion, and then forming the electrical connection body. After inserting the dynamic connection body into a battery case with both ends open, each end of the battery case is joined to each outer edge of the two electrode terminals, and then at least one of the electrodes is connected. A method for manufacturing a lithium secondary battery, comprising injecting a non-aqueous electrolyte solution from an electrolyte solution inlet provided in a terminal and then sealing the electrolyte solution inlet. 20. The method for manufacturing a lithium secondary battery according to claim 19, wherein a crimping and / or welding method is used as a method of joining the concave groove of the internal terminal portion and the current collecting tab. 21. The method of manufacturing a lithium secondary battery according to claim 19, wherein the electrode terminal is arranged at a position where the current collecting tab can be easily crimped and / or welded during the joining operation.