Battery Cell Manufacturing Device and Battery Cell Manufacturing Method

A battery cell manufacturing device according to one embodiment of the present disclosure is a battery cell manufacturing device comprising a battery case in which an electrode assembly and an electrolyte are incorporated, with a pocket part and a pre-sealing part being formed on the outer peripheral surface thereof, and the device including a jig for pressing the pocket part, wherein the jig includes a first jig located at the upper part and a second jig located at the lower part with respect to the pocket part, and wherein pressing and releasing of the first jig and the second jig to the pocket part are repeated at least once to press the pocket part.

CROSS CITATION WITH RELATED APPLICATION(S)

This application claims the benefit of Korean Patent Application No. 10-2021-0012232 filed on Jan. 28, 2021 and Korean Patent Application No. 10-2022-0012372 filed on Jan. 27, 2022 in the Korean Intellectual Property Office, the contents of which are incorporated herein by reference in their entirety.

The present disclosure relates to a battery cell manufacturing device and a battery cell manufacturing method, and more particularly, to a battery cell manufacturing device and a battery cell manufacturing method in which the amount of electrolyte loss is reduced and the quality is made uniform.

BACKGROUND

Along with the technology development and increased demand for mobile devices, demand for secondary batteries as energy sources has been increasing rapidly. Among these secondary batteries, a lithium secondary battery having high energy density and a high voltage, a long cycle lifespan, and a low self-discharge rate is commercially available and widely used.

A pouch for a secondary battery is mainly used as an exterior material for packaging such a secondary battery. The pouch is generally a pouch film having a structure of an outer layer, an adhesive layer, an aluminum layer, an adhesive layer, and an inner layer. However, the pouch-type secondary battery may be damaged in various processes. As an example, there is a problem that a part of the electrolyte in the pouch is pushed out to the outer peripheral surface in the process of sealing the outer peripheral surface of the pouch after the electrode assembly is incorporated into the pouch.

FIG.1is a flowchart showing a conventional battery cell manufacturing process.FIG.2is a diagram showing a battery cell after the pre-sealing step ofFIG.1.FIG.3is a diagram showing a battery cell after the sealing step ofFIG.1.

Referring toFIG.1, the conventional battery cell manufacturing process includes a pre-sealing step (S10) and a sealing step (S20). Referring toFIG.2, the pre-sealing step (S10) is a step of forming a pre-sealing part12at the end part of an outer peripheral surface11of a battery cell10. Further, referring toFIGS.2and3, the sealing step (S20) is a step of forming the sealing part15on the outer peripheral surface11of the battery cell10by a first sealing tool51and a second sealing tool55.

Here, the pre-sealing part12prevents a part of the electrolyte in the pouch from leaking to the outside before the sealing step (S20). However, by the pre-sealing step (S10), a pocket part11pmay be formed between the pre-sealing part12and the central part of the battery cell10on the outer peripheral surface11of the battery cell10. In particular, a part of the electrolyte in the pouch may be contained in the pocket part11p.

However, referring toFIG.3, in the conventional battery cell manufacturing process, the sealing step (S20) is performed in a state in which the electrolyte in the pocket part11pis not sufficiently removed, so that the electrolyte can remain in the pocket part11plocated between the pre-sealing part12and the sealing part15. That is, there is a problem that a part of the electrolyte to be contained in the battery cell10may be lost, and the quality of the battery cell10is not made uniform. Therefore, there is a need to develop a battery cell manufacturing device and a battery cell manufacturing method in which the amount of electrolyte loss is reduced and the quality is made uniform.

DETAILED DESCRIPTION OF THE INVENTION

Technical Problem

It is an object of the present disclosure to provide a battery cell manufacturing device and a battery cell manufacturing method in which the amount of electrolyte loss is reduced and the quality is made uniform.

The objects of the present disclosure are not limited to the aforementioned objects, and other objects which are not described herein should be clearly understood by those skilled in the art from the following detailed description and the accompanying drawings.

Technical Solution

According to one aspect of the present disclosure, there is provided a battery cell manufacturing device comprising a battery case in which an electrode assembly and an electrolyte are incorporated, with a pocket part and a pre-sealing part being formed on the outer peripheral surface of the battery case, and the device including a jig for pressing the pocket part, wherein the jig includes a first jig located at the upper part and a second jig located at the lower part with respect to the pocket part, and wherein pressing and releasing of the first jig and the second jig to the pocket part are repeated at least once to press the pocket part.

The jig may be extended along the pocket part.

A width of the jig may be equal to or smaller than a length of the pocket part.

At least one of the first jig and the second jig may have a surface in contact with the pocket part that is covered with a soft member.

The soft member may be formed of a POM (polyoxymethylene) pad.

The soft member bottom part facing the pocket part may have a structure in which the thickness changes.

The soft member bottom part has a first end part and a second end part, and the thickness of the soft member may decrease as it goes from the first end part adjacent to the pre-sealing part toward the second end part farther from the pre-sealing part relative to the first end part.

The battery cell manufacturing device further includes a sealing tool including a first sealing tool located at an upper part and a second sealing tool located at a lower part, with respect to the pocket part, wherein the sealing tool may heat-seal at least a part of the pocket part pressed by the jig to form a sealing part on the outer peripheral surface of the battery case.

A width of the sealing tool may be equal to or smaller than a length of the jig.

According to another aspect of the present disclosure, there is provided a battery cell manufacturing method comprising a battery case in which an electrode assembly and an electrolyte are incorporated, the method comprising: a pre-sealing step of forming a pocket part and a pre-sealing part on the outer peripheral surface of the battery case; and a pressing step of pressing and bonding the pocket part with a jig, wherein the jig includes a first jig located at the upper part and a second jig located at the lower part, with respect to the pocket part, and wherein in the pressing step, pressing and releasing of the first jig and the second jig to the pocket part may be repeated at least once.

The pressing step may be repeated until the thickness of the pocket part is similar to the thickness of the end part of the outer peripheral surface of the battery case.

The battery cell manufacturing method further includes a sealing step that is performed after the pressing step, wherein in the sealing step, at least a part of the pocket part may be heat-sealed by a sealing tool to form a sealing part on the outer peripheral surface of the battery case.

Advantageous Effects

A battery cell manufacturing device and a battery cell manufacturing method according to an embodiment of the present disclosure presses the pocket part with a jig before sealing the pocket part formed on the outer peripheral surface of the battery case, thereby being able to reducing the amount of electrolyte loss and make the quality uniform.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A description of parts not related to the description will be omitted herein for clarity, and like reference numerals designate like elements throughout the description.

Further, throughout the description, when a portion is referred to as “including” a certain component, it means that the portion can further include other components, without excluding the other components, unless otherwise stated.

FIG.4is a flowchart showing a battery cell manufacturing process according to an embodiment of the present disclosure.FIG.5is a diagram showing a battery cell after the pre-sealing step ofFIG.4.0

Referring toFIGS.4and5, a battery cell manufacturing device according to an embodiment of the present disclosure is a battery cell manufacturing device comprising a battery case100in which an electrode assembly and an electrolyte are incorporated, with a pocket part110pand a pre-sealing part120being formed on the outer peripheral surface110of the battery case100, and the device including a jig300for pressing the pocket part110p.

Here, the jig300includes a first jig310located at the upper part and a second jig350located at the lower part, with respect to the pocket part110p. More specifically, the first jig310and the second jig350may be formed of the same material and shape. However, the present disclosure is not limited thereto, and can be appropriately deformed according to the shape of the battery case100.

Additionally, the first jig310and the second jig350can each perform upward and downward movements. As another example, one of the first jig310and the second jig350is fixed in a state in contact with the pocket part110p, and the remaining one can perform upward and downward movements. However, the present disclosure is not limited thereto, and can be appropriately deformed according to the shape of the battery case100.

Further, the jig300may be extended along the pocket part110p. In other words, the width of the jig300may be extended along the pocket part110p. As an example, the width of the jig300may be equal to or smaller than the length of the pocket part110p.

Thereby, in the battery cell manufacturing device according to an embodiment of the present disclosure, the jig300can relatively uniformly press the pocket part110p, and the quality of the battery cell can be further improved.

Further, in the jig300of the present embodiment, at least one of the first jig310and the second jig350may have a surface in contact with the pocket part110pthat is covered with a soft member310P. As an example, referring toFIG.5, a surface of the first jig310in contact with the pocket part110pmay be covered with a soft member.

As an example, the soft member310P may be formed of a POM (polyoxymethylene) pad. However, the soft member310P is not limited thereto, and any material that can be sufficiently pressed without damaging the pocket part110pcan be applied.

Thereby, in the battery cell manufacturing device according to an embodiment of the present disclosure, a part of the jig300has a surface in contact with the pocket part110pthat is covered with a soft member310P, whereby the pocket part110pcan be uniformly pressed without overlapping each other, and can prevent sealing defects such as wrinkles during sealing from occurring on a part of the pocket part110pthat is subsequently pressed.

FIGS.6to8are diagrams each showing a battery cell in a process in which the pressing step ofFIG.4is repeated.

In the jig300of the present embodiment, the first jig310and the second jig350can repeatedly press and release the pocket part110pat least once to press the pocket part110p. More specifically, referring toFIG.5, the first jig310and the second jig350can each move toward the pocket part110p. Further, referring toFIG.6, the first jig310and the second jig350may be in contact with the pocket part110p. Here, at least a part of the electrolyte contained in the pocket part110pmay move toward the inside of the battery case100.

Additionally, referring toFIGS.7and8, the first jig310and the second jig350can move again to the pressed pocket part110pand press the pocket part110pagain. Here, the remaining part of the electrolyte contained in the pocket part110pmay move toward the inside of the battery case100. If necessary, as shown inFIGS.7and8, the pressing and releasing of the pocket part110pcan be repeated several times according to the movement of the first jig310and the second jig350.

Thereby, in the battery cell manufacturing device according to an embodiment of the present disclosure, the jig300can allow the electrolyte contained in the pocket part110pto move toward the inside of the battery case100and thus, can reduce the amount of electrolyte loss in the battery case100. Further, the jig300may be repeatedly pressed and released on the pocket part110p, whereby the electrolyte remaining in the pocket part110pcan be minimized, and the quality of the battery cell can be further improved.

FIG.9is a diagram showing a battery cell after the pressing step ofFIG.4.FIG.10is a diagram showing a battery cell after the sealing step ofFIG.4.

Referring toFIGS.9and10, in the battery cell manufacturing device according to another embodiment of the present disclosure, the above-mentioned battery cell manufacturing device may further include a sealing tool500together with the jig300.

Here, the sealing tool500includes a first sealing tool510located at the upper part and a second sealing tool550located at the lower part, with respect to the pocket part110p. Here, the first sealing tool510and the second sealing tool550can heat-seal at least a part of the pocket part110ppressed by the jig300to form a sealing part150on the outer peripheral surface110of the battery case100.

Thereby, in the battery cell manufacturing device according to an embodiment of the present disclosure, the sealing tool500can allow the battery case100to be sealed in a state in which the electrolyte contained in the pocket part110plocated between the pre-sealing part130and the sealing part150is minimized. That is, the battery case100can reduce the amount of electrolyte loss and improve the quality of the battery cell.

Further, the first sealing tool510and the second sealing tool550may be formed of the same material and shape. However, the present disclosure is not limited thereto, and can be appropriately deformed according to the shape of the battery case100.

Further, the first sealing tool510and the second sealing tool550may each perform upward and downward movements. As another example, one of the first sealing tool510and the second sealing tool550is fixed in contact with the pocket portion110p, and the remaining one can perform upward and downward movements. However, the present disclosure is not limited thereto, and can be appropriately deformed according to the shape of the battery case100.

Further, the width of the sealing tool500may be equal to or smaller than the width of the jig300. As an example, with respect to the pocket portion110p, the sealing tool500can be disposed adjacently at a position close to the inside of the battery case100.

Thereby, in the battery cell manufacturing device according to an embodiment of the present disclosure, the sealing tool500can allow the sealing part150to form at a position close to the inside of the battery case100in the pocket part110p, whereby a part of the electrolyte in the battery case100can be prevented from being leaked to the outer peripheral surface110of the battery case100in the subsequent charging/discharging process of the battery cell, and the quality of the battery cell can also be improved.

Referring toFIG.4, a battery cell manufacturing method according to another embodiment of the present disclosure is a battery cell manufacturing method comprising a battery case100in which an electrode assembly and an electrolyte solution are incorporated, the method comprising: a pre-sealing step (S100), a pressing step (S200) and a sealing step (S300).

Referring toFIGS.4and5, the pre-sealing step (S100) may be a step of forming the pre-sealing part120on the outer peripheral surface110of the battery case100. Here, the pre-sealing part120may be formed by heat-sealing the upper and lower parts of the outer peripheral surface110of the battery case100using a pre-sealing tool (not shown).

Thereby, in the battery cell manufacturing method according to an embodiment of the present disclosure, a part of the outer peripheral surface110of the battery case100is sealed by the pre-sealing step (S100), so that the electrolyte in the battery case100cannot be leaked to the outside.

Additionally, the pre-sealing part120may be formed at a position spaced apart from the inside of the battery case100by a predetermined distance even on the outer peripheral surface110of the battery case100. Particularly, on the outer peripheral surface of the battery case100, a pocket part110pmay be formed between the inside of the battery case100and the pre-sealing part120. Here, the pocket part110pmay include at least a part of the electrolyte in the battery case100, as described above.

Referring toFIGS.4, and6to8, the pressing step (S200) may be a step in which pressing is performed on the pocket part110pof the outer peripheral surface110of the battery case100. More specifically, the pressing step (S200) can be performed by the above-mentioned first jig310and second jig350. Further, in the pressing step (S200), the pressing and releasing of the first jig310and the second jig350to the pocket part110pcan be repeated at least once.

Thereby, in the battery cell manufacturing method according to an embodiment of the present disclosure, at least a part of the electrolyte contained in the pocket part110pcan move toward the inside of the battery case100by the pressing step (S200).

As an example, the pressing step (S200) may be repeated until the thickness of the pocket part110pis similar to the thickness of the end part of the outer peripheral surface110of the battery case100. Here, the thickness of the end part of the outer peripheral surface110of the battery case100may mean the total thicknesses of the pouch film of the upper case and the pouch film of the lower case constituting the battery case100. However, the time point at which the repetition of the pressing step (S200) ends is not limited thereto, and can be appropriately adjusted according to the production model and the process conditions of the battery cell100.

Thereby, in the battery cell manufacturing method according to an embodiment of the present disclosure, the pressing step (S200) can be repeated until reaching the above-described thickness, and the electrolyte contained in the pocket part110pcan be sufficiently moved into the battery case100. That is, the electrolyte remaining in the pocket part110pcan be minimized, and the quality of the battery cell can also be further improved.

Further, referring toFIGS.4,9, and10, a sealing step (S300) can be performed after the pressing step (S200). Here, in the sealing step (S300) may be a step in which at least a part of the pocket part110pis heat-sealed by the above-mentioned sealing tool500to form the sealing part150on the outer peripheral surface of the battery case.

Thereby, in the battery cell manufacturing method according to an embodiment of the present disclosure, the sealing step (S300) can heat-seal the pocket part110pin a state in which the electrolyte contained in the pocket part110pis minimized. That is, in the sealing step (S300), the battery case100can be sealed with the sealing part150in a state in which the amount of electrolyte loss inside the battery case100is reduced, thereby further improving the quality of the battery cell.

FIG.11is a diagram showing a modification of the battery cell manufacturing device shown inFIG.5.

Referring toFIG.11, in the jig300of the present embodiment, at least one of the first jig310and the second jig350has a surface in contact with the pocket part110pthat is covered with a soft member310P. At this time, the bottom part of the soft member310P′ facing the pocket part110pmay have a structure in which the thickness changes. The soft member (310P′) bottom part may have a first end part (P1) and a second end part (P2), and the thickness of the soft member310P′ increases as it goes from the first end part P1adjacent to the pre-sealing part200toward the second end part P2farther from the pre-sealing part200relative to the first end part P1.

By having a structure in which the thickness of the bottom portion of the soft member310P in contact with the pocket part110paccording to the present embodiment changes, in particular, a structure in which the thickness decreases as it moves away from the pre-sealing part200, the electrolyte can be moved much more efficiently toward the inside of the battery case100at the time of pressing the pocket part110p. Thereby, the electrolyte remaining in the pocket part110pcan be minimized, and the quality of the battery cell can be further improved.

Although the preferred embodiments of the present disclosure have been shown and described above, the scope of the present disclosure is not limited thereto, and numerous changes and modifications can be devised by those skilled in the art using the principles of the invention defined in the appended claims, which also falls within the spirit and scope of the present disclosure.

Description of Reference Numerals100:battery case110:outer peripheral surface of battery case110p:pocket part120:pre-sealing part150:sealing part300:jig500:sealing tool