KR20170104205A - Degassing Device for Manufacture of Secondary Battery and Degassing Process Using the Same - Google Patents

Abstract

The present invention relates to a degassing apparatus for manufacturing a battery cell, the degassing apparatus which secures a sufficient residual amount of an electrolyte within the battery cell, and enables a chamber type device to be mixed with a non-chamber type device at the same time, and a degassing method using the degassing apparatus for manufacturing the battery cell. The present invention provides the degassing apparatus for manufacturing the battery cell, as an apparatus used in a degassing process of removing gases generated in an activation process due to charging and discharging of the battery cell, the degassing apparatus comprising: a chamber in which the battery cell passing through the activation process is located in a state that the battery cell is sealed from the outside; a cutting unit which is located within the chamber to perforate through-holes for gas exhaustion in a gas pocket of the battery cell; a vacuum pump which is located on an outer portion of the chamber and sucks in gas within the chamber to create a vacuum state inside the chamber; a first pipe which includes a ball valve for pipe opening or closing as a pipe mounted on an outer surface of the chamber in a state that the first pipe is communicated with the inside of the chamber; a second pipe which is formed to be communicated with the inside of the battery cell through the through-holes perforated in the gas pocket of the battery cell, and to which an end portion of the first pipe is connected from the outside of the chamber; and a third pipe of which an end portion of one side is connected to the second pipe, of which an end portion of the other side is connected to a vacuum pump, and which includes a throttle valve for controlling amount of the gas sucked in by the vacuum pump.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a degassing apparatus for manufacturing a battery cell and a degassing method using the same,

The present invention relates to a degassing apparatus for manufacturing a battery cell and a degassing method using the same.

2. Description of the Related Art In recent years, the use of secondary batteries as a power source for electric vehicles (EV) and hybrid electric vehicles (HEV) has been realized, and the use area has also been expanded for applications such as grid- Accordingly, a lot of researches on a battery that can meet various demands have been made.

Typically, in terms of the shape of a battery, there is a high demand for a prismatic secondary battery and a pouch-type secondary battery which can be applied to products such as mobile phones with a small thickness, and has advantages such as high energy density, discharge voltage, There is a high demand for lithium secondary batteries such as lithium ion batteries and lithium ion polymer batteries.

In particular, in recent years, a pouch-shaped battery having a structure in which a stacked or stacked / folded electrode assembly is embedded in a pouch-shaped battery case of an aluminum laminate sheet has attracted much attention due to low manufacturing cost, small weight, And its usage is gradually increasing.

Generally, such a pouch-shaped battery is subjected to a process of activating the battery by charging and discharging during the manufacturing process of the battery cell and a degassing process of removing the gas generated in the activation process.

1 is a schematic view schematically showing a degassing process of a conventional pouch-shaped battery cell.

1, the battery cell 100 is formed by impregnating an electrolyte solution in a state where the electrode assembly 110 is housed in the housing part 102 of the battery case 101, and sealing the outer periphery 111 by heat fusion .

The electrode assembly 110 is activated in the state of being impregnated with the electrolytic solution in the housing part 102 through charging and discharging.

The battery cell 100 having undergone the activation process is formed with a through hole 122 in the gas pocket 121 opposed to the housing part 102 and through the through hole 122 in the activation process of the battery cell 100 The generated gas is discharged to the outside of the battery case 101 and removed.

In the battery cell 100 in which the removal of the gas is completed, the gas pocket in which the through hole 122 is drilled is removed, and the remaining portion 123 is sealed by heat fusion.

Thereafter, the battery cell 100 is completed by pressing with a high-temperature press so as to form a uniform outer shape.

However, since the degassing process of the pouch-shaped battery cell is performed by applying a predetermined vacuum and pressure, a part of the electrolytic solution in the battery cell is discharged together with the gas due to a sudden change in pressure, The amount of the battery cell decreases, which causes a problem of deteriorating the performance of the battery cell.

In addition, since the degassing process is performed in a non-chamber type or a chamber type according to the size, shape, and working conditions of the battery cells, it is difficult to provide all of the manufacturing facilities according to the process conditions, It is practically very difficult to change the manufacturing facility in accordance with the manufacturing process.

Therefore, there is a high need for a deaerator capable of ensuring a sufficient amount of electrolyte remaining in the battery cell, and capable of mixing the chamber system or the non-chamber system.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

The inventors of the present application have conducted intensive research and various experiments and have succeeded in manufacturing battery cells having different manufacturing methods according to size, shape, and working conditions with a degassing device operating in two operation modes as described later, It is possible to improve the elasticity of the operation of the manufacturing facility and confirm that the discharge amount of the electrolytic solution can be controlled by using the chamber during the degassing process, and thus the present invention has been accomplished.

To attain the above object, a degassing apparatus for manufacturing a battery cell according to the present invention is an apparatus used in a degassing process for removing gas generated in an activation process by charging and discharging a battery cell,

A chamber in which a battery cell having undergone the activation process is positioned inside the battery cell in a sealed state from the outside;

A cutout positioned in the interior of the chamber for puncturing the through-hole in the gas pocket of the battery cell for discharge of gas;

A vacuum pump located outside the chamber and sucking gas in the chamber to evacuate the interior of the chamber;

A first pipe having a ball-valve for opening and closing a pipe, the pipe being mounted on an outer surface of the chamber in a state of being communicated with the inside of the chamber;

A second pipe configured to communicate with the inside of the battery cell through a through hole formed in a gas pocket of the battery cell and an end of the first pipe connected to the outside of the chamber; And

A third pipe having one end connected to the second pipe and the other end connected to the vacuum pump and having a throttle valve for adjusting the amount of gas sucked by the vacuum pump;

As shown in FIG.

Accordingly, by controlling the opening and closing of the first pipe by the ball valve, the degassing apparatus is operated in various operating modes, so that the battery cells of different manufacturing methods are produced by only one manufacturing facility according to the size, shape, It becomes possible. Also, by controlling the amount of gas in the chamber that is sucked by the vacuum pump through the throttle valve, the loss of the electrolyte can be reduced by controlling the amount of the electrolyte discharged together with the gas inside the battery cell.

In one specific embodiment, the degassing apparatus according to the present invention comprises:

A first operation mode in which the interior of the chamber is set to a non-vacuum state, and the gas inside the battery cell is removed while the second pipe is in communication with the through-hole of the gas pocket; or

The inside of the chamber is set to a vacuum state and the second pipe is communicated with the through hole of the gas pocket or partially communicated or non-communicated with the through hole of the gas pocket, through the first pipe or through the first pipe and the second pipe, A second operating mode for removing gas;

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Specifically, when the deaerator is operated in the first operation mode, the ball valve of the first pipe is switched to a closed state, and the gas inside the battery cell sequentially passes through the second pipe and the third pipe It can be set to a structure which is removed by a vacuum pump.

The ball valve has a structure in which a structure having a through hole at the center of the flow path is located inside and is opened and closed by rotating. When the ball valve is switched to the closed state, the gas inside the battery cell can not move to the first pipe but moves only through the second pipe and the third pipe.

That is, when the deaerator is operated in the first operation mode, the gas inside the battery cell is removed by the second pipe communicating with the gas pocket, so that the gas inside the chamber is not sucked by the vacuum pump, Lt; / RTI >

On the other hand, when the deaerator is operated in the second operation mode, the ball valve of the first pipe is switched to the open state, and the inside of the chamber is set to the vacuum state.

In such a structure, the second pipe may be non-conductive or communicated with the gas pocket, and the flow path of the gas sucked by the vacuum pump depending on whether the second pipe is communicated or not may be slightly different as described below.

First, in the second operation mode, when the second pipe is not connected to the through hole of the gas pocket, most of the gas inside the battery cell is sequentially removed through the first pipe and the third pipe by the vacuum pump , And a small amount of gas is sequentially removed through the second pipe and the third pipe by a vacuum pump.

Secondly, in the second operating mode, when the second pipe communicates with the through-hole of the gas pocket, some of the gas in the battery cell is sequentially removed by the vacuum pump via the first pipe and the third pipe, And the remaining gas in the cell may be removed by a vacuum pump through the second pipe and the third pipe sequentially.

In these various second modes of operation, the cutout having perforations formed in the gas pocket is punched through a through-hole in the gas pocket so that the interior of the battery cell can be exposed to the vacuum environment of the chamber, And then returned to the home position.

In the second operation mode, since the ball valve is switched to the open state, the gas inside the chamber can be introduced into the first pipe.

The gas inside the battery cell is discharged into the chamber through the through-hole in a state where the incising portion perforates the through-hole in the gas pocket. In this state, the vacuum pump simultaneously sucks the gas discharged from the inside of the battery cell and the gas inside the chamber.

In this case, when the diameter of the first pipe is larger than the diameter of the second pipe, the flow rate is proportional to the cross-sectional area value, so that most of the gas is removed via the first pipe and the third pipe sequentially, Are sequentially removed via the second pipe and the third pipe.

As a result, in the second operation mode, the gas discharged into the chamber through the through-hole is sucked into the first pipe together with the gas in the chamber, and some gas inside the battery cell is sucked into the second pipe, It is removed via a pipe.

In this second operation mode, the vacuum pump does not directly inhale most of the gas inside the battery cell, and as a result, the internal pressure of the battery cell is not changed suddenly, and the advantage of the reduced amount of the discharged electrolyte have.

Specifically, when operating in the first operation mode, if the gas inside the battery cell is sucked through the second pipe, the internal pressure suddenly changes within-one-second to -98 Kpa, and the electrolyte solution is discharged Can occur.

On the other hand, when operating in the second operation mode, most of the gas generated inside the battery cell is discharged into the chamber through the through-hole, and then sucked together with the gas inside the chamber, The loss of the electrolytic solution is reduced.

The structure of the ball valve is not particularly limited, but may be a butterfly valve structure.

The butterfly valve structure is advantageous in that it is simple in structure, low in pressure loss, and suitable for a low-pressure gas because the disk inside the valve simply rotates. In the first operation mode or the second operation mode .

The throttle valve may have a structure including a vane for controlling the opening amount of the gas sucked to adjust the pressure inside the chamber.

In the above structure, the structure may further include a stepping motor for controlling the rotation angle of the vane so that the vane can control the degree of vacuum in the chamber.

During the degassing process, the vacuum condition should be at least -80 kPa, preferably -90 kPa, which can be regarded as a stabilization right. However, when the pressure in the chamber is reduced within a short time in the process of reaching the set vacuum condition, the electrolyte may be drawn out from the inside of the battery cell together with the gas inside the chamber. Therefore, The above problem can be solved by increasing the vacuum reaching time.

That is, by controlling the angle of the vane by 0.1 degree, for example, by using the stepping motor, the degree of vacuum of the inside of the chamber is set to a value of -60 kPa, -70 kPa, -80 kPa, -90 kPa, Decompression is possible.

Specifically, the stepping motor may receive feedback on the degree of vacuum in the chamber to control the degree of vacuum in the chamber to a set value. The above feedback is performed at intervals of 0.2 second with respect to the degree of vacuum in the chamber, and the target degree of vacuum can be set through the above process.

The first pipe may be connected to the outside of the chamber at a relatively lower height than a battery cell located inside the chamber. However, the present invention is not limited thereto, and the first pipe may be removed The formation position thereof is not limited to a great extent.

The degassing apparatus according to the present invention may further include an electrolyte tank for collecting the electrolyte solution which becomes solid in the ball valve in the process of sucking the gas, and may be separately disposed outside the chamber.

In this deaerator structure, the chamber may have a structure in which a lower die on which the battery cell is seated and an upper die for pressing the battery cell seated on the lower die are additionally provided.

Specifically, the battery cell may have a structure in which the gas pocket and the battery cell body are seated on the lower die so as to be parallel to the paper surface.

The present invention also provides a method of manufacturing a battery cell using the above-described degassing apparatus.

Such a battery cell manufacturing method

(a) storing an electrode assembly in a housing of a battery case, and sealing the battery case in a state where the electrode assembly is impregnated with an electrolyte solution to manufacture a battery cell having a gas pocket;

(b) charging and discharging the battery cell to activate the battery cell;

(c) puncturing a through hole for sucking gas into the gas pocket of the battery cell;

(d) discharging gas inside the battery cell by applying vacuum and pressure;

(e) a process of removing the gas pocket and then secondary sealing to complete the battery cell;

.

The deaerator according to the present invention can greatly improve the efficiency of the manufacturing process by changing the operation mode according to the size, shape and working condition of the battery cell to be deaerated in the process of manufacturing the battery cell.

The present invention also provides a battery cell manufactured using the above method and a battery pack including at least one of the battery cells, and specific configurations of the battery cell and the battery pack are well known in the art, A detailed description thereof will be omitted.

As described above, the degassing apparatus for manufacturing a battery cell according to the present invention can operate the degassing apparatus by changing the operation mode by regulating the opening and closing of the first pipe by the ball valve, In an operation mode according to an exemplary embodiment, the amount of gas in the chamber sucked by the vacuum pump through the throttle valve is adjusted to discharge the gas in the battery cell together with the gas It is possible to reduce the loss of the electrolytic solution by controlling the amount of the electrolytic solution.

1 is a schematic view schematically showing a degassing process of a conventional pouch-shaped battery cell;
2 is a perspective view schematically illustrating the structure of a degassing apparatus for manufacturing a battery cell according to an embodiment of the present invention;
3 is a schematic view schematically showing a degassing apparatus for producing a battery cell before the degassing process;
4 is a schematic diagram schematically illustrating a degassing process according to one embodiment of the present invention; And
5 is a schematic view schematically illustrating a degassing process according to another embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings according to the embodiments of the present invention, but the scope of the present invention is not limited thereto.

2 is a schematic view schematically showing a structure of a degassing apparatus 200 for manufacturing a battery cell according to an embodiment of the present invention.

2, a degassing apparatus 200 for manufacturing a battery cell includes a chamber 210, a vacuum pump 220, a first pipe 230, a second pipe 240, and a third pipe 250 .

The chamber 210 is a sealed space from the outside and includes therein a lower die 211 on which the battery cell 100 is seated and an upper die 212 for pressing the battery cell 100 seated on the lower die 211 A cut portion 213 for piercing the through hole 122 in the gas pocket 121 of the battery cell 100 and a sealing portion for sealing the remaining portion after the gas pocket 121 is removed Not included).

The first pipe 230 has one end connected to the outer surface of one side of the chamber 210 and the other end connected to the second pipe 240 while communicating with the inside of the chamber 210.

The second pipe 240 is configured such that one end of the second pipe 240 can communicate with the inside of the battery cell 100 through a through hole 122 formed in the gas pocket 121 of the battery cell 100, The third pipe 250 and the first pipe 230, respectively.

The third pipe 250 has one end connected to the second pipe 240 and the other end connected to the vacuum pump 220.

The ball valve 231 and the throttle valve 251 are formed in the first pipe 230 and the third pipe 250 from the outside of the chamber 210, respectively.

The vacuum pump 220 is connected to one end of the third pipe 250 at the rear side of the throttle valve 251 when viewed in the direction 201 of the gas sucked and moved from the chamber 210.

FIG. 3 is a schematic view schematically showing a degassing apparatus for producing a battery cell before a degassing process, and FIG. 4 is a schematic view schematically showing a degassing process according to an embodiment of the present invention.

Referring to FIG. 4 together with FIG. 2 and FIG. 3, before the degassing process, the battery cell 100 is seated on the lower die 211 in parallel to the ground, The second pipe 240 is connected to the inside of the battery cell 100 in a state of being communicated with the through hole 122 formed in the gas pocket 121 by the cutout 213 and the first pipe 230, The ball valve 231 is switched to the closed state (the first pipe is indicated by a dotted line).

When the battery cell 100 is pressed by the upper die 212, the gas inside the pressurized battery cell 100 passes through the through hole 122 and then flows through the second pipe 240 and the third pipe 250 And sequentially sucked into the vacuum pump 220 via the pipe.

Since the first pipe 230 is closed by the ball valve 231 and the gas can not pass therethrough, the non-vacuum state inside the chamber 210 is maintained.

Therefore, when the battery cell 100 is operated in the first operation mode, only the inside of the battery cell 100 is evacuated to remove the gas.

Referring to FIG. 5 with reference to FIG. 2 and FIG. 3, when the degassing apparatus is operated in the second operation mode, the cutout portion 213 forms the through hole 122 in the gas pocket 121, , The ball valve 231 of the first pipe 230 is switched to the open state (the first pipe is indicated by the solid line).

When the battery cell is pressed by the upper die 212, the gas inside the pressurized battery cell 100 is discharged into the chamber 210 through the through-hole 122, and the discharged gas flows through the second pipe 240 Or the first pipe 230, and then is sucked into the vacuum pump 220 through the third pipe 250.

The gas inside the chamber 210 is sucked into the vacuum pump 220 through the first pipe 230 or the second pipe 240 so that the inside of the battery cell 100 and the chamber 210 are evacuated.

In some cases, the second pipe 240 may be directly connected to the through-hole 122 to increase the amount of gas discharged by the second pipe 240.

4 and 5, a first vacuum gauge 235 and a second vacuum gauge 245 are formed at one end of the first pipe 230 and the cutout 213, respectively.

When the degassing process is operated in the first operating mode, the first vacuum gauge 235 does not operate and the second vacuum gauge 245 measures the degree of vacuum inside the chamber 210.

When the degassing process is operated in the second operating mode, the second vacuum gauge 245 does not operate and the first vacuum gauge 235 measures the degree of vacuum inside the chamber 210.

The pressure inside the chamber 210 is adjusted by adjusting a vane (not shown) included in the throttle valve 251 based on the degree of vacuum measured by the vacuum gauges 235 and 245.

3 to 5, after the gas inside the battery cell 100 is removed, the gas pocket 121 is removed, and the open side of the battery cell 100 is sealed by the sealing part 214 Thereby completing the battery cell.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (19)

An apparatus for use in a degassing process for removing gas generated in an activation process by charging and discharging a battery cell,
A chamber in which a battery cell having undergone the activation process is positioned inside the battery cell in a sealed state from the outside;
A cutout positioned in the interior of the chamber for puncturing the through-hole in the gas pocket of the battery cell for discharge of gas;
A vacuum pump located outside the chamber and sucking gas in the chamber to evacuate the interior of the chamber;
A first pipe having a ball-valve for opening and closing a pipe, the pipe being mounted on an outer surface of the chamber in a state of being communicated with the inside of the chamber;
A second pipe configured to communicate with the inside of the battery cell through a through hole formed in a gas pocket of the battery cell and an end of the first pipe connected to the outside of the chamber; And
A third pipe having one end connected to the second pipe and the other end connected to the vacuum pump and having a throttle valve for adjusting the amount of gas sucked by the vacuum pump;
Wherein the deaerator is disposed in the vicinity of the deaerator. The apparatus according to claim 1,
A first operation mode in which the interior of the chamber is set to a non-vacuum state, and the gas in the battery cell is removed while the second pipe is in communication with the through-hole of the gas pocket; or
The inside of the chamber is set to a vacuum state and the second pipe is communicated with the through hole of the gas pocket or partially communicated or non-communicated with the through hole of the gas pocket, through the first pipe or through the first pipe and the second pipe, A second operating mode for removing gas;
Wherein the gas-liquid separator is operated by a gas-liquid separator. 3. The method according to claim 2, wherein, when the deaerator is operated in the first operation mode, the ball valve of the first pipe is switched to a closed state, and the gas inside the battery cell sequentially flows through the second pipe and the third pipe And is removed by a vacuum pump. 3. The battery cell manufacturing method according to claim 2, wherein, when the deaerator operates in the second operation mode, the ball valve of the first pipe is switched to an open state, Degassing device. 5. The battery pack according to claim 4, wherein in the second operation mode, the second pipe is not connected to the through hole of the gas pocket, and the gas inside the battery cell is sequentially passed through the first pipe and the third pipe, And removing the dehydrating agent. 5. The battery pack according to claim 4, wherein in the second operation mode, the second pipe is not connected to the through-hole of the gas pocket, and most of the gas inside the battery cell sequentially passes through the first pipe and the third pipe, And the remaining gas in the battery cell is sequentially removed through the second pipe and the third pipe by the vacuum pump. 5. The method according to claim 4, wherein, in the second operation mode, the second pipe is communicated with or partially communicated with the through-hole of the gas pocket, and a part of the gas inside the battery cell sequentially passes through the first pipe and the third pipe, And the remaining gas in the battery cell is removed by the vacuum pump sequentially through the second pipe and the third pipe. 8. The apparatus of claim 7, wherein in the second mode of operation, the cutout having perforations in the gas pocket is cut through the through-hole of the gas pocket such that the interior of the battery cell is exposed to the vacuum environment of the chamber, And then returning to the original position after the through-hole is drilled. The degassing apparatus for a battery cell according to claim 1, wherein the ball valve comprises a butterfly valve structure. 2. The degasser according to claim 1, wherein the throttle valve includes a vane therein for controlling the amount of gas sucked in to regulate the pressure inside the chamber. The degassing apparatus for a battery cell according to claim 10, further comprising a stepping motor for controlling a rotation angle of the vane so that the vane can adjust the degree of vacuum in the chamber. 12. The apparatus according to claim 11, wherein the stepping motor receives feedback on the degree of vacuum in the chamber to control the degree of vacuum in the chamber to a set value. The apparatus of claim 1, wherein the first pipe is connected to the outside of the chamber at a relatively lower height than a battery cell located inside the chamber. The device according to claim 1, further comprising an electrolyte tank for collecting the electrolytic solution which becomes solid in the ball valve during a gas sucking process. The device of claim 1, wherein the chamber further comprises a lower die on which the battery cell is mounted, and an upper die for pressing the battery cell seated on the lower die. 16. The device of claim 15, wherein the battery cell is seated on the lower die such that the gas pocket and the battery cell body are parallel to the paper surface. A method of manufacturing a battery cell using a degassing apparatus for manufacturing a battery cell according to any one of claims 1 to 16,
(a) a process of accommodating an electrode assembly in a battery compartment of a battery case, and sealing the battery case in a state of being impregnated with an electrolytic solution to manufacture a battery cell having a gas pocket;
(b) charging and discharging the battery cell to activate the battery cell;
(c) puncturing a through hole for sucking gas into the gas pocket of the battery cell;
(d) discharging gas inside the battery cell by applying vacuum and pressure;
(e) removing the gas pocket and sealing the battery cell to complete the battery cell;
And forming a battery cell. A battery cell characterized by being manufactured using the method according to claim 17. A battery pack comprising at least one battery cell according to claim 18.

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