KR100659875B1 - Electrode plate rolling Device for Secondary battery - Google Patents

Abstract

The pole plate winding device for a secondary battery of the present invention includes a body portion on which the pole plate is wound, a drive unit for rotating the body portion, and a variable unit for varying the length of the body portion, and thus the length of the body portion is variable while the pole plate is wound on the body portion. The winding tension of the pole plate being wound has certain advantages in any part of the mandrel.

Variable Mandrel, Winding Tension, Winding Device

Description

Electrode plate rolling device for secondary battery {Electrode plate rolling Device for Secondary battery}

1 is a view schematically showing a pole plate winding apparatus for a secondary battery according to the present invention;

2 shows schematically a mandrel according to the invention,

3 shows a part of a mandrel according to the invention,

Figure 4a, 4b is a view showing the operation of the mandrel applied to the present invention.

<Brief Description of Major Codes in Drawings>

100: mandrel 103: body

103a: first body portion 103b: second body portion

105: clamp 107: pressing portion

109 drive unit 110 rack

111: first pinion gear 113: first variable shaft

115: guide groove 117: elastic member

119: variable shaft 121: second pinion gear

123: second variable axis 125: guide projection

The present invention relates to a pole plate winding apparatus for a secondary battery, and more particularly, to a pole plate winding apparatus for a secondary battery provided with a mandrel for winding the pole plate constituting the electrode assembly in the secondary battery.

Recently, compact and lightweight electric / electronic devices such as cellular phones, notebook computers, camcorders, etc. have been actively developed and produced. These portable electric / electronic devices have a battery pack that can be operated in a place where no separate power source is provided. The built-in battery pack includes at least one battery therein for outputting a predetermined level of voltage for driving the portable electric / electronic device for a period of time.

In consideration of economical aspects, battery packs employ secondary batteries that can be charged and discharged in recent years. Typical secondary batteries include nickel secondary batteries such as nickel-cadmium (Ni-Cd) batteries, nickel-hydrogen (Ni-MH) batteries, lithium (Li) batteries, and lithium ion (Li-ion) batteries.

In particular, the lithium secondary battery has an operating voltage of 3.6 V, which is three times higher than that of a nickel-cadmium battery or a nickel-hydrogen battery, which is widely used as a power source for portable electronic equipment, and is rapidly increasing in terms of high energy density per unit weight. to be.

Such lithium secondary batteries mainly use lithium-based oxides as positive electrode active materials and carbon materials as negative electrode active materials. In general, a battery is classified into a liquid electrolyte battery and a polymer electrolyte battery according to the type of electrolyte, and a battery using a liquid electrolyte is called a lithium ion battery, and a battery using a polymer electrolyte is called a lithium polymer battery. Moreover, although a lithium secondary battery is manufactured in various shapes, typical shapes include cylindrical shape, square shape, and pouch type.

Typically, a lithium secondary battery includes an electrode assembly, a case for a lithium secondary battery accommodating the electrode assembly, an electrolyte solution injected into the case for the lithium secondary battery and closing the case to enable the movement of lithium ions.

The electrode assembly is interposed between the positive electrode plate and the negative electrode plate, and the positive electrode plate and the negative electrode plate to prevent a short, and is wound by a separator capable of moving electrolyte or ions.

At this time, the electrode assembly is formed by the insertion groove is formed in the center is wound by the rotating mandrel.

The mandrel includes a body formed such that its cross section has a major axis and a minor axis and an insertion groove formed at the center of the body.

The end where the first electrode plate, the second electrode plate, and the separator are stacked is inserted into the insertion groove. Next, when the body is rotated, the laminated electrode plate and the separator are wound on the outer surface of the body, and the wound end is finished by the fixing tape.

However, in the conventional winding mandrel, when the body is rotated, the winding tension of the pole plate on both ends of the mandrel relative to the long axis of the mandrel is greater than the winding tension of the pole plate on the other part. Therefore, the electrode plate wound on both ends to increase tension has a problem in that it is difficult to separate the mandrel from the electrode plate after being wound on the mandrel.

In addition, when the electrode assemblies having different winding tensions of the respective parts are accommodated in the case of the secondary battery and the electrolyte is injected, there is a problem in that deformation occurs in the portion where the tension is large.

Therefore, the secondary battery has a problem in that the performance of the battery is degraded due to the deformation of the electrode assembly.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and an object of the present invention is to provide a pole plate winding device for a secondary battery that evens the winding tension of the pole plate wound by the mandrel.

The present invention for achieving the above object provides a pole plate winding device for a secondary battery including a body portion wound on the outer surface, a drive unit for rotating the body portion and a variable unit for varying the length of the body portion.

The body portion is formed to have a long axis and a short axis in the cross-section, it may be divided into the first and second body parts based on the short axis may be installed at a predetermined interval.

Preferably, the variable unit reduces the interval between the first and second body parts sequentially according to the degree of winding of the electrode plate to the first and second body parts.

The variable unit may include first and second pinion gears connected to end portions of the first and second body portions, first and second pinion gears respectively connected to end portions of the first and second connection shafts, and the first and second pinions. The rack is meshed with the gear, and the first and second pinion gear is connected to the first and second pinion gear for pressing the first and second pinion gear.

The drive unit is preferably connected to the rack.

The variable shaft may include a first variable shaft installed at one side of the first pinion gear and formed in a tubular shape, and a second variable shaft installed at one side of the second pinion gear and inserted into the first variable shaft. Can be.

The second variable shaft may have a guide protrusion formed on one side thereof, and the first variable shaft may have a guide groove formed to correspond to the guide protrusion.

An inner side of the first variable shaft may be provided with an elastic member having one side in contact with the first variable shaft and the other side in contact with an end portion of the second variable shaft.

The first and second pressurizing parts may be air cylinders.

Preferably between the first and second body portion is provided with a clamp for fixing the end of the pole plate.

Hereinafter, with reference to the drawings will be described in detail the mandrel for pole plate winding of a secondary battery according to the present invention.

1 is a view schematically showing a pole plate winding apparatus for a secondary battery according to the present invention, Figure 2 is a view schematically showing a mandrel according to the present invention, Figure 3 is a view showing a part of the mandrel according to the present invention. to be.

Referring to these drawings, the secondary battery winding device is a device for winding the electrode assembly 200 constituting the secondary battery, the electrode assembly 200 is a first electrode plate 210 is attached to the first electrode tab (not shown) ), A shape in which a second electrode plate 220 having a second electrode tab (not shown) and separators 230 and 230a interposed between the first electrode plate 210 and the second electrode plate 220 are wound. Is made of.

That is, in the electrode assembly 200, the first electrode plate 210, the second electrode plate 220, and the separators 230 and 230a each consist of one strip, and the separator 230 and the first electrode plate ( 210, the separator 230a, and the second electrode plate 220 are disposed in this order, and are wound in a jelly-roll type. A fixing tape 250 is attached to the outermost surface of the electrode assembly 200 to fix the electrode assembly 200 so that the electrode assembly 200 wound in a jelly roll type is not loosened.

The first electrode plate 210 may be an anode, and includes a first active material layer coated on both sides of a first electrode current collector made of a thin metal plate having excellent conductivity, for example, aluminum (Al) foil. have. Chalcogenide compounds are used as the active material, and complex metal oxides such as LiCoO 2, LiMn 2 O 4, LiNiO 2, LiNi 1-x Cox O 2 (0 <x <1), and LiMnO 2 are used in the present embodiment. It is not limited.

The second electrode plate 220 may be a cathode, and includes a second active material layer coated on both surfaces of the second electrode current collector made of a conductive metal plate, for example, copper (Cu) or nickel (Ni) foil. have. As the second active material, carbon (C) -based material, Si, Sn, tin oxide, composite tin alloys, transition metal oxides, lithium metal nitrides, or lithium metal oxides are used. It is not limited.

The separators 230 and 230a prevent a short between the first electrode plate 210 and the second electrode plate 220 and only move the charge of the lithium secondary battery 100, for example, lithium ions. It is made possible, but it is made of any one selected from the group consisting of polyethylene, polypropylene and a copolymer (co-polymer) of polyethylene and polyflopropylene, but the material is not limited in this embodiment. The separators 230 and 230a may be formed to have a width wider than that of the first electrode plate 210 and the second electrode plate 220 to prevent a short circuit between the first electrode plate 210 and the second electrode plate 220. Do.

The winding device includes a supply unit 120, 130, 130a, 140 to which the first and second electrode plates 210 and 220 and the separators 230 and 230a, which constitute the electrode assembly 200, and the supplied first and second electrode plates ( A cutter 400 for cutting the 210 and 220 and the separators 230 and 230a to a predetermined length, a mandrel 100 for winding the first and second electrode plates 210 and 220 and the separators 230 and 230a, and respective supply units And a feed roller 500 for guiding the transfer of the first and second electrode plates 210 and 220 and the separators 230 and 230a unwound from the 120, 130, 130a and 140.

The supply parts 120, 130, 130a, and 140 may include a first electrode plate supply part 210 in which the first and second electrode plates 210 and 220 are wound, a second electrode plate supply part 140 in which the second electrode plate 220 is wound, and a separator. It consists of supply parts 130 and 130a. In this case, each of the supply units 120, 130, 130a, and 140 is disposed such that the separators 230, 230a are interposed between the first electrode plate 210 and the second electrode plate 220.

When the first and second electrode plates 210 and 220 wound on the supply parts 120 and 140 are unwound in the first electrode plate supply part 120 and the second electrode plate supply part 140 at predetermined intervals from the respective supply parts 120 and 140. Electrode tab attachment parts 217 and 227 are provided to attach the first and second electrode tabs.

The cutter unit 400 cuts the first and second electrode plates 210 and 220 and the separators 230 and 230a unwound from the respective supply units 120, 130, 130a and 140 to a predetermined length. That is, the cutter 400 cuts each of the first and second electrode plates 210 and 220 and the separators 230 and 230a into a length for forming one electrode assembly 200.

 The mandrel 100 rotates the first and second electrode plates 210 and 220 and the separators 230 and 230a while rotating, and the body part 103, the driving part 150 for rotating the body part 103, and the body part ( A variable unit for varying the length of 103).

The body portion 103 is formed so that its cross section is substantially elliptical and has a long axis and a short axis, and is divided into two parts based on the short axis and separated into a first body part 103a and a second body part 103b. Here, the first and second body parts 103a and 103b are disposed at predetermined intervals.

Here, the clamp 105 is installed between the first body portion 103a and the second body portion 103b and ends of the first and second electrode plates 210 and 220 and the separators 230 and 230a wound on the mandrel 100. Fix it.

The variable unit sequentially spaces the gap between the first and second body parts 103a and 103b according to the degree in which the first and second electrode plates 210 and 220 and the separators 230 and 230a are wound on the body part 103. It is formed to reduce. Accordingly, the variable unit is connected to the first and second connecting shafts 111a and 121a and the first and second connecting shafts 111a and 121a, respectively, which are connected to the ends of the first and second body parts 103a and 103b, respectively. Variable shaft 119 and the first connecting the first and second pinion gear (111,121), the rack 110, the first and second pinion gear (111, 121) and the first and second pinion gears (111, 121) And first and second pressurizing parts 107a and 107b connected to the first and second pinion gears 111 and 121a respectively connected to the second and second pinion gears 111 and 121 to pressurize the first and second pinion gears 111 and 121.

The first and second pressure parts 107a and 107b may use an air cylinder to press the first and second connection shafts 111a and 121a from both sides or to restore the first and second connection shafts 111a and 121a to their original positions.

The driving unit 109 is preferably connected to the rack 110 to rotate the body portion 103.

The variable shaft 119 connects the first and second pinion gears 111 and 121, and the first and second body parts 103a and the first and second pinion gears 111 and 121 move toward the center along the rack 110. It guides the movement of 103b) and consists of a 1st variable shaft 113 provided in the 1st pinion gear 111, and the 2nd variable shaft 123 provided in the 2nd pinion gear 121. As shown in FIG.

The first variable shaft 113 is formed in a tubular shape such that the second variable shaft 123 is insertable therein. In addition, the first variable shaft 113 is provided with an elastic member 117 inside, one side is in contact with the inner wall of the first variable shaft 113, the other side is in contact with the end of the second variable shaft 123. The elastic member 117 prevents the second variable shaft 123 from being inserted more than a predetermined interval when the second variable shaft 123 is inserted into the first variable shaft 113 and guides the restoration of the second variable shaft 123 to its original position. do.

The conveying roller 500 is rotated by a rotating shaft and a rotating driver (not shown), and the first and second electrode plates 210 and 220, the separators 230 and 230a, and the fixed tape 250 are unwound from the respective supply parts 120, 130, 130a and 140. To guide the transfer.

Hereinafter, the operation of the electrode plate winding apparatus for secondary batteries of the present invention by the above-described configuration.

First, each supply unit 120, 130, 130a, 140, and 150 unwinds the first and second electrode plates 210 and 220 and the separators 230 and 230a.

The unrolled first and second electrode plates 210 and 220 and the separator 230 are led to the cutter unit 400 by the feed rollers 500 installed at predetermined positions.

In this case, the first and second electrode tabs are attached to the first and second electrode plates 210 and 220 by electrode tab attachment portions 217.227 at predetermined positions.

Ends of the first and second electrode plates 210 and 220 having the first and second electrode tabs and the separators 230 and 230a may be attached to the clamp 105 provided between the first body portion 103a and the second body portion 103b. Is fixed by.

At this time, the first body portion 103a and the second body portion 103b of the mandrel 100 are disposed at a predetermined interval.

When the first and second electrode plates 210 and 220 and the separators 230 and 230a are fixed by the clamp 105, the driving unit 109 connected to the rack 110 is driven to rotate the mandrel 100.

When the mandrel 100 is rotated, the first body part 103a and the second body part 103b are wound on the outer surface of the electrode plates 210, 220, 230, and 230a, and are connected to the first and pinion gears 111 and 121. The first and second pressing parts 107a and 107b for pressing the second connecting shafts 111a and 121a are driven.

The first and second pressurizing parts 107a and 107b sequentially press the first and second connection shafts 111a and 121a connected to the first and second pinion gears 111 and 121 so that the first and second electrode plates 210 and 220 and the separator are sequentially pressed. The distance between the first body part 103a and the second body part 103b is reduced according to the extent to which the 230 and 230a are wound.

That is, as shown in FIGS. 4A and 4B, when the first and second pressurizing parts 107a and 107b press the first and second pinion gears 111 and 121, the first pinion gear connected to the first body part 103a ( The second pinion gear 121 connected to the second body portion 103b and 111 is moved toward the center of the body portion 103 along the rack 110 engaged with the first and second pinion gears 111 and 121. At this time, the second variable shaft 123 connected to the second body portion 103b is inserted into the first variable shaft 113 connected to the first body portion 103a. In the second variable shaft 123, the guide protrusion 125 formed on the outer surface thereof is inserted by the guide of the guide groove 115 formed on the first variable shaft 113.

Here, the first and second electrode plates 210 and 220 and the separators 230 and 230a may have the mandrel 100 in a state where the first body portion 103a and the second body portion 103b are not moved toward the center of the body portion 103. ), The winding tension applied to both ends of the mandrel 100 increases as the first and second electrode plates 210 and 220 and the separators 230 and 230a are wound, but the first body portion 103a and the second body portion are increased. Since 103b is moved toward the center of the body portion 103, the winding tension applied to both ends of the mandrel 100 may be acted in the same manner as the plane of the mandrel 103.

The first and second electrode plates 210 and 220 and the separators 230 and 230a wound by the mandrel 100 may be cut by the cutter unit 400 to have a predetermined length.

When the first and second electrode plates 210 and 220 and the separators 230 and 230a are wound, the fixed tape supply unit 150 disposed on one side of the first and second electrode plates 210 and 220 and the separators 230 and 230a may be disposed outside. The supplied fixing tape 250 is attached to form the electrode assembly 200.

Meanwhile, after the winding of the first and second electrode plates 210 and 220 and the separators 230 and 230a is finished, the first body portion 103a and the second body portion 103b are next to the first and second electrode plates 210 and 220. The separators 230 and 230a are restored to their initial positions by the elastic member 117 installed inside the first variable shaft 113 so as to be wound up.

According to the present invention, the electrode plate winding device for secondary batteries is installed at predetermined intervals after the mandrel is separated, and the winding tension of the electrode plates wound on the mandrel as the electrode plates are sequentially reduced as the electrode plates are wound is any There is also a certain advantage in the part.

In addition, the electrode plate winding device for a secondary battery has an advantage that the winding tension of the mandrel is constant so that the electrode plates are stretched to prevent the generation of a defective electrode assembly.

In addition, since the electrode plate has a constant winding force applied to both ends of the mandrel and a winding tension applied to the plane, after the end of the winding, the mandrel and the wound electrode plate are easily separated.

Claims (10)

delete A first electrode plate, a separator, a second electrode plate, and a separator wound on an outer surface thereof, the body part being separated and formed into first and second body parts spaced apart from each other; A driving part connected to the body part to transmit a driving force and rotating the body part in one direction such that the first and second electrode plates and the separator are wound around the body part; And a variable unit for sequentially varying an interval between the first body part and the second body part according to winding tensions of the winding objects wound on the body part. delete The method of claim 2, The variable unit may include first and second connecting shafts connected to ends of the first and second body parts, respectively; First and second pinion gears respectively connected to ends of the first and second connection shafts; A rack engaged with the first and second pinion gears; A variable shaft connecting the first and second pinion gears; And And a first and second pressurizing part connected to the first and second pinion gears to pressurize the first and second pinion gears. The method of claim 4, wherein The driving unit pole plate winding apparatus for a secondary battery, characterized in that connected to the rack. The method of claim 4, wherein The variable shaft is installed on one side of the first pinion gear, the first variable shaft formed in a tubular shape; And And a second variable shaft installed at one side of the second pinion gear, the second variable shaft being inserted into the first variable shaft. The method of claim 6, The second variable shaft is formed with a guide protrusion on one side, The first variable shaft is a pole plate winding apparatus for a secondary battery, characterized in that the guide groove is formed to correspond to the guide projection. The method of claim 7, wherein The inside of the first variable shaft, the pole plate winding apparatus for a secondary battery, characterized in that one side is in contact with the first variable shaft, the other side is in contact with the end of the second variable shaft. The method of claim 4, wherein And the first and second pressurizing parts are air cylinders. The method of claim 2, A pole plate winding device for a secondary battery, characterized in that a clamp for fixing the end of the pole plate is provided between the first and second body portion.

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