JP3460267B2 - Battery electrode winding device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery electrode winding device for forming a spiral laminated electrode body by stacking and winding a long positive electrode, the negative electrode and a separator.

[0002]

2. Description of the Related Art Recent remarkable advances in electronic technology have been made to reduce the size and weight of electronic equipment. Along with this, a battery as a mobile power source is required to be small, lightweight and have high energy density.

As a battery capable of obtaining such a high output and a high energy density, the electrode material of the positive electrode and the negative electrode in which the active substance is attached to the electrode current collector (usually a metal foil) is rolled into a roll shape. There is a battery that uses a wound wound body as an electrode.

In the battery using the wound electrode body as described above, the battery electrode winding device that winds the electrode current collector around the winding core at the time of manufacturing the battery electrode winding device has four unwinding shafts and a winding coil. It is composed of parts and.

On the four unwinding shafts, a raw material of a negative electrode material in which a negative electrode mixture is applied on both sides of a negative electrode current collector and a positive electrode in which a positive electrode mixture is applied on both sides of a positive electrode current collector A raw material of an electrode material and a raw material of a separator made of a microporous polypropylene film are mounted respectively.

A winding core is attached to the winding section, and the winding core is rotatably driven at a constant direction and at a constant speed to produce a wound electrode body. That is, the electrode material in which the separator, the positive electrode, the separator, and the negative electrode are sequentially laminated is 4
The electrode material is wound around the winding shaft of the book, and the winding core is driven to rotate, whereby the electrode material is wound around the winding core, and a wound electrode body having a predetermined winding amount is manufactured.

[0007]

In the conventional battery electrode winding device, when the wound electrode body is manufactured, the electrode material (including the separator) is rotated by rotating the winding body as described above. Due to the winding around the body, the tension applied to the electrode material becomes insufficient. The wound electrode body manufactured in such a state has poor adhesion between the electrodes, which leads to deterioration of battery performance, that is, energy density, cycle characteristics, heavy load characteristics, and the like.

In view of this problem, if the tension applied to the electrode material when it is fed is increased, a new problem arises in that the risk of the separator being cut is greatly increased. In particular, a separator having a practically used aperture ratio of about 30% or more, that is, the area occupied by micropores on the surface is 30%.
When using the above separator, it becomes very difficult to manufacture a high-performance battery.

In addition, since the winding is driven by the core, that is, the inner side is driven, when the number of windings around the core is several tens of times or more, a separator is most likely to crack near the inner circumference. Therefore, the rate of occurrence of internal short circuit increases significantly. Therefore, at present, in a battery in which a wound electrode body is manufactured by winding an electrode current collector by driving a winding core,
It is virtually impossible to produce a large capacity (5 Ah or more).

The present invention has been made in view of the above-mentioned various problems, and an object thereof is to improve energy density and cycle characteristics.
Moreover, it is an object of the present invention to provide a battery electrode winding device capable of using a separator having a large porosity of about 40% or more and significantly improving heavy load characteristics.

[0011]

DISCLOSURE OF THE INVENTION The present invention, which is proposed to achieve the above-mentioned object, provides a positive electrode in which a positive electrode mixture is applied to both surfaces of a long positive electrode current collector and a long electrode. The aperture ratio between the negative electrode current collector and the negative electrode coated with the negative electrode mixture on both surfaces is 4
With 0% or more of the separator interposed, while maintaining the tension of the positive electrode, the negative electrode and the separator at a desired value by a tensioner, the positive electrode, the negative electrode and the separator are superposed and wound on a winding core, In a battery electrode winding device that forms a spiral laminated electrode body, a rotary drive roller is brought into contact with the peripheral surface of the winding core body via the laminated electrode body, and the rotary drive roller is rotationally driven. By doing so, the positive electrode, the negative electrode, and the separator are superposed and wound on the winding core to form a spiral laminated electrode body.

In this case, it is desirable to provide a pressure contact roller which is in pressure contact with the laminated electrode wound around the peripheral surface of the core body.

Further, it is desirable that a plurality of the rotary drive rollers be provided.

Furthermore, it is desirable that a plurality of the pressure contact rollers be provided.

In the battery electrode winding device according to the present invention, the positive electrode, the negative electrode, and the separator to which desired tensions are respectively applied by the tensioner are superposed and wound on the winding core to form a spiral laminated electrode body. A spiral laminated electrode body is formed by rotating and driving the laminated electrode body wound around the peripheral surface of the winding core body by contacting a rotation driving roller.

[0015]

EXAMPLES Examples in which the battery electrode winding device according to the present invention is applied to a non-aqueous electrolyte secondary battery will be described below with reference to the drawings.

The non-aqueous electrolyte secondary battery to which the present invention is applied uses as the negative electrode a substance capable of being doped and dedoped with lithium ions such as lithium, a lithium alloy, and a carbon material, and also used as a positive electrode. A lithium composite oxide such as a lithium cobalt composite oxide is used. This battery has high battery voltage, high energy density,
It is a battery with excellent cycle characteristics.

The electrode of the non-aqueous electrolyte secondary battery is a negative electrode 11 made of KH carbon which is a carbon material capable of doping and dedoping lithium, and a positive electrode made of LiCoO ₂ which is a composite oxide of lithium and a transition metal. The electrode portion composed of 12 and 12 is wound around the winding core body a plurality of times via the separator 13 to form a winding electrode body. This wound electrode body is manufactured using a battery electrode winding device.

As shown in FIG. 1, the battery electrode winding device according to the present invention comprises unwinding shafts 1a to 1d, four tensioners 2 and a winding section 3.

The unwinding shaft 1b is mounted with a raw material of the negative electrode material 11 in which the negative electrode mixture is applied on both sides of the negative electrode current collector, and the unwinding shaft 1d is provided with positive electrodes on both sides of the positive electrode current collector. The raw material of the positive electrode material 12 coated with the mixture is mounted on the unwinding shafts 1a and 1c, and the raw material of the separator 13 made of a microporous polypropylene film is mounted on the unwinding shafts 1a and 1c.

The tensioner 2 has the unwinding shafts 1a to 1d.
4 units are provided corresponding to. This tensioner 2
Has a narrow, substantially rectangular shape made of metal, and has one end 2
The a is mounted on the substrate 4 and is rotatable around the one end 2a. A raw material of the electrode materials 11 and 12 or a raw material of the separator 13 (hereinafter simply referred to as a raw material) is attached to the other end portion 2b. This tensioner 2
When the electrode is wound, the other end 2b to which the original fabric is attached is rotated counterclockwise by a predetermined angle around the one end 2a, whereby the original fabric is pulled downward in FIG. Will increase. Similarly, by rotating the other end portion 2b clockwise by a predetermined angle, the original fabric is pulled upward in FIG. 1 and the tension is reduced. The tensioner 2 thus applies the desired tension to the web.

As shown in FIG. 2, the winding section 3 is composed of a winding core 5 and a rotation driving roller 6.

The winding core 5 has a metal cylindrical shape, one end surface of which is installed on the substrate 4 and is rotatably installed. The rotary drive roller 6 has a cylindrical shape, and is installed below the core body 5 in the drawing, with its cylindrical side surface always in contact with the cylindrical side surface of the core body 5. The rotary drive roller 6 has one end surface mounted on the substrate 4, receives a rotary drive force from a rotary drive controller 7 installed on the substrate 4, and is rotationally driven at a desired constant speed about its axis. It

In the battery electrode winding device according to the present invention, the respective tension rolls fed from the respective unwinding shafts 1a to 1d are adjusted to have a desired tension by the tensioners 2 and fed into the winding section 3. . In the winding unit 3, as shown in FIG. 2, the electrode stack 14 in which a separator, a negative electrode, a separator, and a positive electrode are stacked in this order is used as an electrostatic removal blower 1.
The static electricity charged on the surface of the separator 13 is removed by 5, and each original surface is cleaned by each cleaning unit 16. One end of the electrode laminate 14 is fixed to the winding core 5 by a method such as tape or welding, and the rotary drive roller 6
Is driven to rotate in the direction of arrow M in FIG.
2 is rotated in the direction of arrow N in FIG. 2 and the electrode laminated body 14 is wound while being pressed against the winding core 5 and the rotation driving roller 6 with a predetermined pressure to complete the wound electrode body.

In the battery electrode winding device according to the present invention, the electrode laminated body 14 is pressed against the winding core 5 by the rotary driving roller 6 which receives the driving force and is driven to rotate.
Since the winding core 5 is wound, the rotation driving force from the outside acts on the winding core 5 to wind the winding. Therefore, during the winding, even if a relatively large tension is applied to the electrode laminated body 14, the separator 13 located in the vicinity of the inner circumference of the winding core, which is most likely to be damaged, does not receive a large tensile force and is damaged. Since it is difficult, by winding the electrode laminated body 14 with appropriate tension, it is possible to manufacture a wound electrode body having high adhesion between the positive electrode and the negative electrode.

Therefore, a practical separator having a large aperture ratio , that is, a separator having a large area of fine pores on the surface can be sufficiently used, and the adhesion between the positive electrode and the negative electrode constituting the wound electrode body is improved. By doing so, it is possible to significantly improve the performance (energy density, cycle characteristics, heavy load characteristics, etc.) of the non-aqueous electrolyte secondary battery, especially the cycle characteristics.

Next, another example of the battery electrode winding device according to the present invention will be described with reference to the drawings. The same parts as those of the battery electrode winding device shown in FIGS. 1 and 2 are designated by the same reference numerals and described.

First, the first modification will be described. This first modified example is different in that a pressure contact roller 8 is provided in the winding section 3 as shown in FIG.

In the first modification, the winding section 3 is composed of a core body 5, a rotation driving roller 6, and a pressure contact roller 8. As shown in FIG. 3, the press roller 8 is installed above the core body 5 such that its cylindrical side surface is always in contact with the cylindrical side surface of the core body 5. The pressure contact roller 8 has one end surface installed on the substrate 4 and is rotatably installed. A pressurizing air cylinder 1 is provided above the press roller 8 via a winding force control rod 17.
7 is installed. A predetermined force is applied to the pressing roller 8 downward by the pressurizing air cylinder 18 in FIG.

In this first modification, each unwinding shaft 1a
Each tensioner 2 feeds each of the above-mentioned raw materials sent from 1d to 1d to the winding section 3 with its tension set to a desired value. In the winding unit 3, as shown in FIG. 3, an electrode laminate 14 in which a separator, a negative electrode, a separator and a positive electrode are laminated in this order is removed by a static electricity removing blower 15 to remove static electricity charged on the surface of the separator 13. Then, each cleaning unit 16 cleans each original surface. One end of the electrode laminate 14 is fixed to the core 5 by a method such as tape or welding, and the rotary drive roller 6 is rotationally driven in the direction of arrow M in FIG. 3 rotates in the directions of arrows N and L in FIG. 3 so that the electrode laminate 14 is applied with a predetermined pressure between the winding core 5 and the rotation driving roller 6 and between the winding core 5 and the pressure roller 8. The wound electrode body is completed while being pressed and wound.

In the battery electrode winding device shown in FIG. 3,
Similarly to the above-described device, the electrode laminate 14 is wound around the core body 5 while being pressed against the core body 5 by the rotary drive roller 6 that receives the driving force and is rotationally driven. Is driven by the rotation driving force from the outside to be wound. Therefore, even if a relatively large tension is applied to the electrode laminate 14 during winding, the separator 13 located near the inner circumference of the winding core that is most likely to be damaged is not applied with a large tension and is damaged. Since it is difficult, by winding the electrode laminated body 14 with appropriate tension, it is possible to manufacture a wound electrode body having high adhesion between the positive electrode and the negative electrode.

Therefore, it is possible to use a practical separator having a large aperture ratio , that is, a separator having a large area of fine pores on the surface, and the adhesion between the positive electrode and the negative electrode forming the spirally wound electrode body is improved. By doing so, it is possible to significantly improve the performance (energy density, cycle characteristics, heavy load characteristics, etc.) of the non-aqueous electrolyte secondary battery, especially the cycle characteristics.

Next, a second modification of the present invention will be described. This second modified example has substantially the same configuration and function as the first modified example, but as shown in FIG. 4, in the winding section 3, two rotary drive rollers 6a and 6b are provided. The difference is that

In the second modification, as shown in FIG. 4, the winding portion 3 is provided with the winding core 5 and the winding core 5 which is provided obliquely below the winding core 5 in the left and right directions. Doing 2
It is composed of rotary drive rollers 6a and 6b and a pressure contact roller 8.

In this second modification, each unwinding shaft 1a
Each tensioner 2 feeds each of the above-mentioned raw materials sent from 1d to 1d to the winding section 3 with its tension set to a desired value. In this winding unit 3, as shown in FIG. 4, the electrode laminate 14 in which a separator, a negative electrode, a separator and a positive electrode are laminated in this order is removed by an electrostatic removal blower 15 from the static electricity charged on the surface of the separator 13. Further, each cleaning unit 16 cleans each original surface. One end of the electrode laminated body 14 is fixed to the winding core 5 by a method such as tape or welding, and the two rotary drive rollers 6a and 6b are rotationally driven in the direction of arrow M in FIG. The core body 5 and the pressure contact roller 8 rotate in the directions of arrow N and arrow L in FIG. 4, respectively, so that the electrode laminate 14 is between the core body 5 and the rotation driving rollers 6a and 6b, and the core body 5.
It is wound while being pressed against each other at a predetermined pressure between the pressure roller 8 and the pressure roller 8 to complete a wound electrode body.

In the second modification of the battery electrode winding device according to the present invention, as in the device shown in FIG. 1, the core is formed by the two rotary drive rollers 6a and 6b which are driven to rotate by the driving force. Since the electrode laminate 14 is wound around the core body 5 while being pressed against the body 5, the winding drive force is applied to the core body 5 from the outside so that the core body 5 is wound. Therefore, during the winding, even if a relatively large tension is applied to the electrode laminated body 14, the separator 13 located in the vicinity of the inner circumference of the winding core, which is most likely to be damaged, does not receive a large tensile force and is damaged. Since it is difficult, by winding the electrode laminated body 14 with appropriate tension, it is possible to manufacture a wound electrode body having high adhesion between the positive electrode and the negative electrode.

Therefore, a separator having a large aperture ratio , which is highly practical, that is, a separator having a large area of fine pores on the surface, can be sufficiently used, and the adhesion between the positive electrode and the negative electrode forming the spirally wound electrode body is improved. By doing so, it is possible to significantly improve the performance (energy density, cycle characteristics, heavy load characteristics, etc.) of the non-aqueous electrolyte secondary battery, especially the cycle characteristics.

Next, a third modification of the battery electrode winding device according to the present invention will be described. The third modification has substantially the same configuration and function as the first modification, but as shown in FIG. 5, in the winding unit 3, two rotation driving rollers 6a and 6b and two rotation driving rollers 6a and 6b are provided. Pressure contact rollers 8a and 8
The difference is that b is provided.

In the third modified example, as shown in FIG. 5, the winding portion 3 is provided with the winding core 5 and the winding core 5 which is provided obliquely below the winding core 5 in the left and right directions. Doing 2
The rotary drive rollers 6a and 6b are provided as bases, and a pressure contact roller 8 is provided obliquely above and to the left of the core body 5 and is in pressure contact with the core body 5.

In this third modification, each unwinding shaft 1a
The tensions 2 set the tensions of the respective webs sent from 1d to 1d to desired values, and the webs are sent to the winding section 3. In this winding unit 3, as shown in FIG. 5, the electrode stack 14 in which a separator, a negative electrode, a separator, and a positive electrode are stacked in this order is removed by a static electricity removal blower 15 from the static electricity charged on the surface of the separator 13. Further, each cleaning unit 16 cleans each original surface. One end of the electrode laminate 14 is fixed to the winding core 5 by a method such as tape or welding, and the two rotation driving rollers 6a and 6b are each driven to rotate in the direction of arrow M in FIG. The body 5 and the two pressing rollers 8a and 8b are respectively shown in FIG.
The electrode laminate 14 rotates in the directions of the middle arrow N and the arrow L so that a predetermined pressure is applied between the core body 5 and the rotation driving rollers 6a and 6b and between the core body 5 and the pressure contact rollers 8a and 8b. The wound electrode body is completed while being pressed and contacted with.

In the third modification of the battery electrode winding device according to the present invention, as in the device shown in FIG. 1, the core is formed by the two rotary drive rollers 6a and 6b which are rotationally driven by receiving the driving force. Since the electrode laminate 14 is wound around the core body 5 while being pressed against the body 5, the winding drive force is applied to the core body 5 from the outside so that the core body 5 is wound. Therefore, during the winding, even if a relatively large tension is applied to the electrode laminated body 14, the separator 13 located in the vicinity of the inner circumference of the winding core, which is most likely to be damaged, does not receive a large tensile force and is damaged. Since it is difficult, by winding the electrode laminated body 14 with appropriate tension, it is possible to manufacture a wound electrode body having high adhesion between the positive electrode and the negative electrode.

Therefore, a practical separator having a large aperture ratio , that is, a separator having a large area of fine pores on the surface can be sufficiently used, and the adhesion between the positive electrode and the negative electrode constituting the wound electrode body is improved. By doing so, it is possible to significantly improve the performance (energy density, cycle characteristics, heavy load characteristics, etc.) of the non-aqueous electrolyte secondary battery, especially the cycle characteristics.

[0042]

In the battery electrode winding device according to the present invention, the positive electrode, the negative electrode, and the separator to which desired tensions are respectively applied by the tensioner are superposed and wound on the winding core to form a spiral laminated electrode body. In doing so, since the spirally laminated electrode body is formed by rotating the laminated electrode body wound around the peripheral surface of the winding core by contacting the rotation driving roller, the energy density and the cycle characteristics can be improved. It is possible to improve the characteristics, and moreover, it is possible to use a separator having an aperture ratio of 40% or more, and it is possible to significantly improve heavy load characteristics.

Further, in the battery electrode winding device, the energy density and the cycle characteristics can be further improved by providing the pressure contact roller which is in pressure contact with the laminated electrode body wound around the peripheral surface of the winding core. And the aperture ratio is 40
%, It is possible to use a separator having a content of at least%, and the heavy load characteristics can be further improved significantly.

[Brief description of drawings]

FIG. 1 is a front view schematically showing the structure of a battery electrode winding device according to the present invention.

FIG. 2 is a front view schematically showing a winding section that is a component of the battery electrode winding device according to the present invention.

FIG. 3 is a front view schematically showing a winding section that is a component of a first modification of the battery electrode winding device according to the present invention.

FIG. 4 is a front view schematically showing a winding section that is a constituent element of a second modification of the battery electrode winding device according to the present invention.

FIG. 5 is a front view schematically showing a winding section that is a component of a third modification of the battery electrode winding device according to the present invention.

[Explanation of symbols]

1a to 1d unwinding shaft, 2 tensioner, 3
Winding unit, 4 substrate, 5 winding core body, 6 rotation drive roller, 7 rotation drive control device, 8 pressure contact roller

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01M 10/04 H01M 6/02 H01M 10/40

Claims (4)

(57) [Claims] 1. An aperture ratio between a positive electrode in which a positive electrode mixture is applied on both sides of a long positive electrode current collector and a negative electrode in which a negative electrode mixture is applied on both sides of a long negative electrode current collector. 40% or more of the separator is interposed, and the tension of the positive electrode, the negative electrode, and the separator is set to a desired value by a tensioner, and the positive electrode, the negative electrode, and the separator are superposed and wound on a winding core, In a battery electrode winding device for forming a spiral laminated electrode body, a rotary drive roller is brought into contact with the laminated electrode body wound around the peripheral surface of the core body to rotationally drive the rotary drive roller. By doing so, the above-mentioned positive electrode, the above-mentioned negative electrode, and the above-mentioned separator are piled up on the above-mentioned winding core, and it winds up, and forms a spiral laminated electrode body. 2. The battery electrode winding device according to claim 1, further comprising a pressure roller that is pressed against the laminated electrode body wound around the peripheral surface of the winding core. 3. The battery electrode winding device according to claim 1, wherein a plurality of the rotation driving rollers are provided. 4. The battery electrode winding device according to claim 2, wherein a plurality of the pressure contact rollers are provided.